| OpenOffice::OODoc::XPath - Low-level navigation in the documents |
blankSpaces(length)cloneContent(oodoc_xpath_object)createSpaces(length)createElement(xml)decode_text(utf8_string)encode_text(editable_string)dispose()exportXMLBody()exportXMLContent()exportXMLElement(element)flatten(element)getAttributes(element)getBody()getFlatText(element)getObjectCoordinates(object)getText(element)getTextList(path)getXMLContent([filehandle])getXPathValue(xpath_expression)isOpenDocument()makeXPath(expression)removeElement(element)resetCurrentContext()save([filename])selectNodesByXPath(xpath_expression)appendTextChild(text)flatten()selectFrameElementByName(name)
OpenOffice::OODoc::XPath - Low-level navigation in the documents
This module is a low-level class which uses OODoc::File (without inheriting anything from it) along with the classes defined in the XML::Twig module. It's a common basis for the other, more user- friendly, document-oriented modules. It uses XPath expressions in order to retrieve any document element (but it doesn't provide a full implementation of the XPath standard). In addition, while the most part of the provided methods are OpenDocument-aware, this module could be used against any other kind of XML documents, simply because it benefits from all the features of XML::Twig. Such a possibility may prove useful for applications that simultaneously process OpenDocument and non-OpenDocument XML files.
The OpenOffice::OODoc::XPath class should not be explicitly used in the applications, because all its features are available in more user-friendly classes such as OODoc::Text, OODoc::Styles, OODoc::Image, OODoc::Document and OODoc::Meta. The present manual page is provided to describe the common methods and properties that are available with all these classes.
This chapter can be skipped by programmers who are only interested in upper level methods provided by the OODoc::Text, ::Styles, ::Image and ::Meta modules. Understanding these modules is easier and using them requires less Perl and XML expertise. However, calling OODoc::XPath methods remains a good rescue option as it allows all kinds of operations on all types of XML elements contained in any OpenDocument-compliant file.
OODoc::XPath is the common foundation of OODoc::Meta, OODoc::Text, OODoc::Styles and OODoc::Image. It contains the lowest layer of navigation services for XML documents and handles the link with OODoc::File for file access. Its primary role is as an interface with the XML::Twig API.
In the present manual chapter, you will see ``elements'' often mentioned. When it says that a module expects a parameter or returns an element (either singly or as a list), it is referring to an XML element. It is important to distinguish elements from their content (elements being simply references to XML data structures). To read or modify the content of an element such as its text or XML attributes, use the accessors also available within OODoc::XPath.
In most cases where XPath methods require a reference to an element as an argument, there are two ways of proceeding:
- reference the element directly (obtained previously)
- or give an XPath expression and a position, being a string and an integer respectively; for example, the pair ('//office:body/text:p', 12) or ('//text:p', 12) represents the thirteenth occurrence of the 'text:p' element, i.e. the 13th paragraph (occurrences are numbered starting from 0).
The second way requires the knowledge of an appropriate XPath expression (according the OOo/OpenDocument XML format specification). And a given XPath expression is not necessarily the same with an OpenDocument as in an OpenOffice.org document. So you should preferently use high level accessors (provided by derivative classes such as OODoc::Document) and avoid XPath hardcoding. However, you know you can at any time reach any element with XPath.
Of course, you will never need to use XPath expressions in order to
reach the most common text elements (such as paragraphs), because the
OODoc::Text module provides more friendly accessors (for example, you
will probably use the getParagraph() method and forget ``//text:p'').
Some methods accept both forms which means that if the first parameter is recognised as an element reference, the position does not need to be given. Therefore the number of arguments for certain OODoc::XPath methods can vary.
For those who really want to access all areas there are also OODoc::XPath methods which allow unrestricted access to every element or XML attribute via an access path in XPath syntax. If you are into this kind of thing, we recommend you obtain good syntax reference manuals for XPath and OpenDocument and a supply of aspirin.
Methods which may return several lines of text (e.g. getTextList) do so either in the form of an unique character string containing ``\n'' separators or in table form.
Unless otherwise stated, the word 'document' in this chapter only refers to XML documents contained within OODoc::XPath objects and not, say, OpenDocument files (as an end user would use).
Amongst the different methods which return elements, attributes or text, some are called getXxx, others selectXxx or findXxx. Read methods whose names start with ``get'' generally refer to an unfiltered object or list, whereas others return an object or list filtered according to a parameter value. In this latter case the search parameter is treated as a standard expression and not an exact value. This means that if the search criteria is ``xyz'', all text containing ``xyz'' will be considered a match. To restrict the search to text exactly equal to ``xyz'', use ``^xyz$'' as the search criteria (following Perl regular expression syntax).
Several methods allow you to place copies of or references to elements (from other documents or from other positions in the same document) in any position in the current document. This offers powerful manoeuvrability but only if these placements conform with the destination position's context.
For example, you can easily copy a paragraph from one document to another but only if you knowingly modify the paragraph's style attribute if that style is not already defined in the destination document. You can also copy the style but only if you are sure that this style is not already defined by another unknown style in the destination document (and so on).
For advanced users familiar with the XML::Twig API, it might be interesting to know that all the objects called ``elements'' in the following chapters are objects of the OpenOffice::OODoc::Element class, which is an XML::Twig::Elt derivative. So all methods associated with this class are directly applicable to these elements, on top of the functionality described in this manual. However, the knowledge of XML::Twig is not mandatory.
Important note: The applications should not explicitly work with this class. We recommend using OODoc::Meta and OODoc::Document (which are both OODoc::XPath derivatives). These two objects provide highest-level methods which are neater and more productive. Explicit use of OODoc::XPath methods (which sometimes require large numbers of parameters) should only be considered as a last resort in unexpected circumstances for access to any element or XML attribute not handled by more friendly methods. However, the present manual chapter could prove helpful because all the common features of OODoc::Meta and OODoc::Document are described here.
Short Form: odfXPath(<parameters>)
Returns a new OpenDocument connector, i.e. an interface which
can be used for subsequent operations on a well-formed document.
This constructor should not be called directly; it's implicitly
triggered each time a Meta or Document object is created.
The document is loaded and parsed according to various options.
The most used option is 'file'; it simply allows the application
to process an OpenDocument file selected by its path/name in the
file system.
Example:
my $doc = odfXPath
(
file => "myfile.ods",
part => "content"
);
# ... lot of processing ...
$doc->save;
Returns a new document connector. In the example above, the object
is loaded from a regular OpenDocument file, that is the most current
option, but there are other possibilities. It's possible to use
flat XML (available as a string in memory, or loaded from a file).
In addition, this constructor is able to create a new document
from scratch.
Because every feature of OODoc::XPath is inherited by OODoc::Document
and OODoc::Meta (see the corresponding manual pages), odfXPath() is
generally not explicitly invoked in a real application. Its silently
used through odfDocument() or odfMeta().
Parameters are named (hash key => value). The constructor must get
at least one parameter giving a means of obtaining the XML document
that it will represent. Several options are available; each one is
represented through the following examples:
# option 1 (using an existing flat XML document)
my $doc = odfXPath(xml => $xml_string);
# option 2 (using a previously created OOo file interface)
my $oofile = odfContainer('source.odt');
my $doc = odfXPath(container => $oofile, part => 'meta');
# option 3 (using a regular OOo file directly)
my $doc = odfXPath(file => 'source.odt', part => 'content');
# option 4 (multiple instances against a single file)
my $content = odfXPath(file => 'source.odt', part => 'content');
my $meta = odfXPath(file => $content, part => 'meta');
my $styles = odfXPath(file => $content, part => 'styles');
Remember "odfXPath()" represents "OpenOffice::OODoc::XPath->new()"
in the instructions above, and you can (and should) use this shortcut
provided that you have loaded the main OpenOffice::OODoc module, and
not only and explicitly the OpenOffice::OODoc::XPath module.
The first form uses an XML string directly (previously loaded or
created by the program). To be used for very specific applications
working with flat XML documents exports and not with standard
OOo/OpenDocument files.
The second method links OODoc::XPath to an existing OODoc::File
object (through the "container" option) and indicates which XML part it
is to extract (metadata, content, styles, etc). The OODoc::File is an
abstraction of an already open ODF container. It can be shared, i.e.
several OODoc::XPath objects can be instantiated with the same
OODoc::File object, and this possibility must be used when
several OODoc::XPath objects have to bring consistent changes in
a single file (see option 4 below). In order to create the
required OODoc::File object, simply use odfFile() with a filename
as argument (for advanced use, see OpenOffice::OODoc::File).
The third method is the easiest, because the user just provide
a filename and a member, and all the file interface is run silently
(i.e. an invisible OODoc::File object is automatically created and
used to get the content). It's probably the most used approach; its
recommended when the user doesn't need to get more than one member
in the same file.
The 'part' option is a selector that tells what component is needed
(content, styles, metadata, ...) knowing that an OODoc::XPath object
can handle only one component. Its default value is 'content'.
If the application needs to process, say, the content and the styles
in the same session, it must create two, or more, OODoc::XPath objects
possibly associated with the same file interface. The appropriate way
is shown in our last example above. The first instance is associated
with a filename. Then the other instances are created with the first
one, provided as the value of the 'file' option instead of a filename.
The constructor tries to be user-friendly: if the 'file' value is
a character string, it's regarded as a filename, but if this value,
is an existing OpenOffice::OODoc::XPath object, the new object is
automatically connected to the same file interface as the other one.
The file interface is transparently provided by a common shared
OpenOffice::OODoc::File object (you can safely ignore the features
of this object, but a corresponding manual chapter is available for
more details).
Be careful: creating more than one OpenOffice::OODoc::XPath objects
linked by their 'file' parameters to the same explicit filename (and
not linked with each other) produces useless extra I/O operations and
possible conflicts.
Caution: being associated with a common interface via OODoc::File,
none of these OODoc::XPath objects should be deleted before the final
save() call for this archive. So by calling a save, the File object
"calls up" all the XPath objects which were "connected" to it in order
to "ask" each of them for the changes which were made to the XML
(content, styles, meta, etc.). The results are unpredictable if any
of them is absent when called.
If the provided filename has a ".xml" or ".XML" suffix, or whatever
the name if the 'flat_xml' option is set to 1, the file is processed
as flat XML and not as a regular OOo file. No OODoc::File object is
created, and the result of a subsequent call of the save() method
produces a flat XML export (and not a regular OOo/OpenDocument file).
You can pass the optional parameter 'element' in any case where the
constructor is called without the 'xml' parameter. Bearing in mind
that an OODoc::XPath object will not necessarily handle an entire
XML document, this extra parameter indicates the name of the XML
element to be loaded and handled. If the 'element' parameter is not
given for an OpenDocument file, a default element will be chosen
according to the following table:
'meta' => 'office:document-meta'
'content' => 'office:document-content'
'styles' => 'office:document-styles'
'settings' => 'office:document-settings'
'manifest' => 'manifest:manifest'
Conversely, the 'element' parameter becomes mandatory if the chosen
XML element is not listed above. Through OODoc::File, OODoc::XPath
can actually access archives which are not necessarily in
OpenDocument format and may be, for example, "databases" of
presentation and content templates.
If the application needs to create a new document, and not process
an existing one, an additional option must be passed:
create => "class"
where "class" must be one of the following list: "text",
"spreadsheet", "presentation" or "drawing", according to the needed
content class. And, for very special needs, the user can pass an
additional "template_path" to select an ad hoc directory of XML
templates instead of the default one. This user-provided directory
must have the same kind of structure and content as the "templates"
subdirectory of the OpenOffice::OODoc installation.
An additional 'opendocument' option can be provided and set to 'true'
or 'false'. If this option is 'false', the new document is created
according to the OpenOffice.org 1.0 format instead of the OASIS
OpenDocument format. The default format is OpenDocument. The
'opendocument' option works for new documents only and is ignored
unless the 'create' option. This module can create and process either
OpenOffice.org 1.0 documents or ODF documents but can't directly
convert a document from one format to the other one.
OODoc::XPath can process OOo documents provided through XML flat
files as well as in the compressed (zip) format. The given file is
automatically processed as flat XML if either it's name ends by ".xml"
or the 'flat_xml' option is set to '1'. When processing a flat XML
file, OODoc::XPath doesn't load the OODoc::File zip interface. So,
a subsequent call of the save() method can only export the document
as flat XML.
An optional 'readable_XML' can be passed. If this option is provided
and set to 'on' or 'true', the resulting XML will be smartly indented
(and, of course, more space-consuming). This feature is intended for
debugging purposes and should not be used in production.
The 'local_encoding' option can be set with the appropriate value
when a particular character set (and not the default one) must be
used for a document.
A 'read_only' can be provided and set to 'true' in order to prevent
the current member from being written back to the physical ODF file
when the save() method is called.
Other optional parameters can also be passed to the constructor (see
Properties below).
Adds a new element or existing element to the list of child elements
of an existing parent element given first (by [path, position] or by
reference).
The argument after the position argument can be an XML element name.
Example:
$content->appendElement
(
'//office:body', 0, 'text:p',
text => "New text"
);
adds a paragraph containing the phrase "New text" to the end of the
document body. (Remember that in the case of an OpenDocument text
file (Writer), it would be better to use the appendParagraph method of
OpenOffice::OODoc::Text as this requires fewer parameters.
If the 'text' option is omitted, an empty element is created (in the
above example it would be an empty paragraph or line feed).
You can pass the 'attribute' or 'attributes' option which is a hash
whose keys are the XML attribute names and whose values are the XML
attribute values. Use of these options depends on the type of
document and the type of element and requires knowledge of
OpenDocument conventions.
Example:
$my_style =
{
'style:name' => 'P1',
'style:family => 'paragraph'
};
$content->appendElement
(
'//office:automatic-styles', 0, 'style:style',
attribute => $my_style
);
creates a new paragraph style called 'P1' in the list of "automatic
styles" ("automatic styles" are styles which are not explicitly
indicated in the styles list as it appears to the end user).
This method lets you add any kind of element into a document, even
exotic ones. With the most common OpenDocument objects (e.g.
paragraphs), though, it is easier to use the specialist methods
contained in other modules.
The 'name' argument can be replaced by an existing element in the
same OODoc::XPath object or in another. In which case no element is
created but the existing element is simply referenced with a new
position even though it remains in its old position. Caution: any
modification of an element which is referenced several times in one
or more documents is made to all references. If you want to add a
similar but separate element, you must use replicateElement which
produces a new element from the content of an existing one.
The 'name' argument can also be replaced by an XML string. This
string must correspond to the correct XML description of a UTF-8
encoded OpenDocument element. For example, it could be a
string which had been previously exported using the exportXMLElement
method of OODoc::XPath, or extracted from an OpenDocument file by
some other application. If for any reason you absolutely have to
use a non-UTF8 XML string which contains 8-bit characters (accented
letters, etc.), you can always convert the string using the
encode_text method before passing it to appendElement. Of course,
the problem will not arise if you are absolutely sure that the string
only contains ASCII (7 bit) characters. XML syntax is checked, but it
is up to the user to verify that the element import conforms to
OpenDocument XML grammar.
The following piece of code produces the same result as the first
example:
$xml = '<text:p text:style-name="Standard">' .
'New text' .
'</text:p>';
$content->appendElement
(
'//office:body', 0, $xml
);
Using this method, after one or more element creations by direct
importation of XML strings, it might be useful to call the
reorganize method (but not absolutely necessary).
=head3 appendLineBreak(element)
Appends a line break to a text element. This method allows the user
to create a single text element (ex: a paragraph) including one or
more breaks, instead of separate elements.
The example below appends a new text in a new line to the end of
an existing paragraph:
my $p = $doc->getElement('//text:p', 5);
$doc->appendLineBreak($p);
$doc->extendText($p, 'A new line in the same paragraph');
=head3 appendSpaces(element, length)
Appends a sequence of multiple spaces to a text element, knowing that
a string containing repeated spaces shouldn't be stored as is in a
document (see setText() and spaces() for details about repeated
spaces).
=head3 appendTabStop(element)
Appends a tab stop ("\t") to a text element.
blankSpaces(length)
See spaces().
cloneContent(oodoc_xpath_object)
Cancels the entire document contents of the current instance and
replaces it with a reference to the contents of another OODoc::XPath
object.
Example:
$doc1 = OpenOffice::OODoc::XPath->new
(
file => 'template.ods',
member => 'styles'
);
$doc2 = OpenOffice::OODoc::XPath->new
(
file => 'sheet.ods',
member => 'styles'
);
$doc2->cloneContent($doc1);
$doc2->save;
This sequence replaces the styles and page layout of 'sheet.ods'
with those of 'template.ods'.
The above example could easily have been written without even using
OODoc::XPath by acting directly on the files. For example, extract
the 'styles.xml' member from 'template.ods' and insert it into
'sheet.ods'. The use of OODoc::XPath and the cloneContent method
guarantees that the transferred content corresponds to an
OpenDocument document and allows reads/writes to it on the fly.
Caution: the "cloned" content is not physically copied. Calling this
method references one single physical content in two documents. Any
modifications made to the content of either of these two documents
applies equally to the other and vice-versa.
Accessor to get or set the class of the document content. If the
current member is a document content, returns its class according
to the OpenDocument terminology, i.e. one of the following values:
"text", "spreadsheet", "presentation", or "drawing".
Returns an empty string if the current member is not a document
content (if it's, for example, the "meta" or "styles" member).
This accessor is read-only.
createSpaces(length)
See spaces().
createElement(xml)
Creates a new element without attributes which is not inserted in a
document.
Example:
my $element =
$doc->createElement
('my_element', 'its content');
creates a new XML element without attributes and returns its
reference.
Instead of a name, the first argument can be the full XML
description of the element. Example:
my $element = $doc->createElement
('<text:p>My text</text:p>');
This new element is temporary: it is not linked to any document. It
is destined to be used later by another method.
The name can contain a namespace prefix which would look like this:
'namespace:name'.
In its second form, a well-formed XML string can be supplied as a
single argument. The recognition criteria is the presence of the "<"
character at the beginning of the argument. See appendElement for
comments on the direct insertion of XML.
Explicit calls to createElement should be rare. This method is
normally called silently by higher-level methods which are capable
of creating an element, inserting it in a document's XML tree and
giving it attributes (see appendElement and insertElement).
Creates an empty frame. A frame is an OpenDocument object which
controls a rectangular area where a visible content is displayed.
Possible contents for a frame are text boxes or images.
This method works is not focused on a particular document class
(for example, it works on text documents as well as on presentations),
but the visible effects of some options are not always exactly the
same.
Possible options are:
'name' => unique name
The 'name' is an identifier; if provided, it should be unique for
the document.
'attachment' => existing container
The value of this option, if provided, must be an existing element
which can contain a text box according to the OpenDocument rules.
Such an object may be, for example, a draw page if the current
document class is 'presentation' or 'drawing', or a paragraph if
this class is 'text'.
'page' => page number or name
The effects of the 'page' option depends on the content class of the
current document. If this option is used, it indicates that the frame
will be anchored to a page, and the given value is a page number.
It does not matter if, when createFrame() is called, this number is
beyond the end of the document or not. If the content class of the
document is "presentation" (Impress) or "drawing" (Draw), then the
page option must be either the visible name or the object reference
of an existing draw page. Caution: the 'page' option is ignored if
'attachment' is provided; in the other hand, either 'page' or
'attachment' nust be provided in order to really include the new frame
in the document.
'position' => coordinates
The coordinates are provided as a string. They go from left to right
and top to bottom. Coordinates should be given here in the form of a
string "x,y", and the default unit is centimeter. You can choose
any other OpenDocument-supported unit instead by attaching the
corresponding usual abbreviation, such as "12.5cm, 35mm" which is the
same as "125mm, 3.5cm" or "12.5,3.5", etc. The point ("pt") unit is
allowed as well. The default coordinates are "0, 0". By default,
the coordinates are relative to the anchor point. So, the coordinates
are directly page-related if a valid 'page' option is provided only,
but if the box is attached to, say, a paragraph, the origin of the
coordinates is the beginning of the paragraph. However, the real
interpretation of the coordinates depends on the style. With some
style definitions, the coordinates may just be ignored (ex: if the
style says "the frame is centered", OpenOffice.org will center the
frame whatever its stored coordinates). According to other possible
style definitions, the coordinates could be counted from the right
and/or from the bottom and not from the left/top.
'size' => the size of the box
Provided using as a string using the same syntax and units as the
position, the 'size' option is strongly recommended knowing that a
sizeless frame couldn't be properly displayed. The width comes
first in the string. The height is sometimes ignored, according to
the style of the frame: by default, the display height of a text box
(which is a particular frame) is automatically adjusted to the
content.
'style' => style name
The 'style' option allows the application to set the frame style.
Caution, a text style can't be used as a frame style. A frame
style controls the box properties only (border, background, shadow,
and so on), and not the content properties. Reusing an existing frame
style through this option is generally a good idea.
=head3 currentContext([context])
Accessor allowing the application to change the context for some
search methods (including getElement()).
The default context is the root of the document. By setting the
current context to a lower level object, the application can restrain
the search to the descendants of this object.
In the example below, the getElement() method retrieves a paragraph
by order number in a previously selected section, and not in the whole
document.
my $section = $doc->getElement("//text:section", $s_number);
$doc->currentContext($section);
my $paragraph = $doc->getElement("//text:p", $p_number);
Without argument, simply returns the previous current context.
See also resetCurrentContext().
decode_text(utf8_string)
Caution: this method is a non-exported class method. It must be used
like this:
OpenOffice::OODoc::XPath::decode_text($utf8_string);
and not from an OODoc::XPath instance.
Decodes a UTF-8 string and returns an 8 bit character translation
of it out of the user's character set, as defined by the following
variable:
$OpenOffice::OODoc::XPath::LOCAL_CHARSET
for which the default value is 'ISO-8859-1'. See the Perl/Encode
manual for the list of supported character sets.
OpenDocument uses UTF-8 XML encoding.
Explicit calls to this method should be rare. It is used internally
by methods which return text extracted from document content (e.g.
getText).
Warning to contributors: any method which returns text extracted
from ODF documents is based on decode_text; so any modification or
improvement of the decoding logic should be made there.
encode_text(editable_string)
Class method.
Encodes "local" character strings (for writing to ODF documents).
Example:
$string = OpenOffice::OODoc::encode_text($local_string);
The local character string is defined by the following global
variable:
$OpenOffice::OODoc::XPath::LOCAL_CHARSET
for which the default value is 'ISO-8859-1'.
Explicit calls to this method should generally be avoided. It is
used internally by methods which insert text or attribute values
into documents (e.g. setText).
dispose()
Deletes the calling document object. Recommended as soon as the
object is no longer needed by the application, and sometimes
mandatory to avoid memory leaks, especially in long-running processes.
exportXMLBody()
Returns the XML string for use by another application representing
the body of a document, without UTF8 decoding.
exportXMLContent()
See getXMLContent()
exportXMLElement(element)
Returns the XML string which represents a particular document
element (style definition, paragraph, table cell, object, etc.) for
use by another application without UTF8 decoding.
This method is principally designed to allow remote exchanges of
elements between programs using any XML storage or transfer method.
It acts as "sender" whilst the "receiver" can use appendElement or
insertElement (for example) to insert any exported elements into a
document. Example:
# sender programme
# ...
open (EXPORT, "> transfer.xml");
print EXPORT $doc->exportXMLElement('//text:p', 15);
close EXPORT;
# receiver programme
# ...
open (IMPORT, "< transfer.xml");
$doc->appendElement('//office:body', 0, <IMPORT>);
close (IMPORT);
In this example, a paragraph is transferred but it could just as
easily be any content, presentation or metadata element.
Conversely, this method is not needed when transferring an element
from one document to another in the same program (or from one
document position to another). An element can be copied directly
from within the same program by reference or replication without
going via its XML (see appendElement(), insertElement() and
replicateElement()).
Appends the given text to the previous content of the given
element. If the optional 'offset' element is provided, the
new element is inserted at the given position.
Example:
$doc->setText($p, "Initial content");
$doc->extendText($p, " extended");
Assuming $p is a regular text element (ex: a paragraph), its
content becomes "Initial content extended".
If the second argument is an element itself, it's appended
as is to the first element. This feature can be used, for
example, in order to append sequences of repeated spaces:
$doc->setText($p, "Begin");
$spaces = $doc->spaces(6);
$doc->extendText($p, $spaces);
$doc->extendText($p, "End");
After the code sequence above, the $p element contains:
"Begin End"
knowing that a single string containing repeated spaces could
not be properly processed by extendText() or setText().
(See also setText()).
Returns all the children of the given element whose content matches
the given filter (regexp).
If the third argument ('replacement') is given, every string which
matches the filter in each child element will be replaced by this
'replacement' value. This 'replacement' argument can be a character
string or a function reference. (See replaceText() method below.)
Filtering and possible replacement only affects an element's content
and not its attributes.
This method is mostly for internal use. We recommend using other
methods for the selective extraction of elements.
flatten(element)
Converts in place the content of the given element to a flat string,
removing any structure. Same as $element->flatten() (see flatten()
in the "Element methods" section below). If no element is provided,
"flattens" the current context element, which is, by default, the
root of the document (be careful !).
=head3 getAttribute(path, position, name)
Returns the 'name' value of the chosen element (or undef if name is
not defined or if the element does not exist).
Example:
my $style =
$doc->getAttribute('//text:p', 15, 'text:style-name');
returns the style for paragraph 15.
getAttributes(element)
Returns a list of the element's attributes in the form of a hash
whose keys are the attributes' XML names.
getBody()
Returns the root of the document body. The document body is the
main container of all the displayable content not including page
headers, page footers, and page backgrounds.
Returns the list of the descendants of the given context element
strictly matching the given tag. Example:
my $section = $doc->getSection("SectionName");
my @paragraphs = $doc->getDescendants('text:p', $section);
Here, @paragraphs is the list of all the paragraphs which are the
descendants (at every level) of a given section (the getSection()
method is described in the OpenOffice::OODoc::Text chapter).
If the second argument is not provided, the current context of the
document is used (see currentContext()).
=head3 getElement(path [, position [, context]])
This method is provided in order to allow the user to retrieve any
element in any kind of XML document (ODF-compliant or not) using an
application-provided XPath expression. It should be used with elements
whose type is not explicitly supported by the more focused (and more
user-friendly) methods, described in other manual chapters (::Text,
::Styles, ::Meta, and ::Document).
It returns an element's reference from an XPath path and a position
(or undef if the given xpath does not indicate an existing element).
The position argument is used to select a particular element, in the
order of the document, knowing that the given xpath expression could
select a set of elements. Without it, getElement() returns the first
element matching the given xpath.
The XPath expression applies in the current context, and not always
in the whole document (see currentContext()). However, if the
reference of a previously selected element is provided as a third
argument, the given element is used as the context.
Position indicators start at 0 just like in Perl tables (and some
other programming languages).
Example:
my $p = $doc->getElement('//table:table', 0)
indicates an element containing the first table of a text document
or first sheet of a spreadsheet.
Positions can also be counted backwards from the end by giving
negative values, i.e. position -1 being the last element. Thus:
my $h = $doc->getElement('//text:h', -2);
indicates the second-last header of a text document.
Note: None of the two examples above should be used in a real
application, knowing that the ::Text module provides getTable() and
getHeading() that do the job without XPath coding.
When successful, this method ensures that the returned object is
indeed an element and not another type of node (e.g. attribute,
text, comment, etc.). Such an object is never a printable text; it's
either a text container (whose content may be extracted using
getText() or getFlatText()) or a non-text element (such as a style,
a font declaration, a variable field, a document properties container,
etc).
=head3 getElementList(path)
Returns a list of all elements at a specified path.
Example:
my @ref_summary = $doc->getElementList('//text:h');
The above example returns a table containing all header elements of
a text document.
The path can of course be a more complex XPath expression
stipulating, for example, a selection of attribute values. In most
cases, you should avoid complicating things unnecessarily
(especially in Text, Image and Styles modules), as there are methods
for searching by element type, attribute and content which are much
easier to use and avoid the need to supply XPath expressions.
Note: the returned list contains elements in the sense of getElement
and not a list of element contents.
getFlatText(element)
Like getText() below, but without rendering of possible tab stops,
line breaks, repeated spaces, or any other markup. The returned text
is a just a decoded flat string.
=head3 getFrameElement(name/number)
Selects the frame identified by the given name, or by the given order
number in the document context.
=head3 getNodeByXPath(xpath_expression)
A low-level method which returns the node corresponding to the given
XPath expression, if it exists in the document. This method (which
gives unrestricted access to the entire content of a document) is
designed for use with the unexpected. You will obviously need to be
familiar with XPath syntax (not documented here) as well as
OpenDocument structure. See also selectNodesByXPath().
getObjectCoordinates(object)
Returns the coordinates (X, Y) of the target object, if any. This
method makes sense with "positioned" objects, i.e. with frames and
frame-like objects (images, text boxes).
In an array context, the coordinates are returned as two distinct
strings (horizontal, then vertical position). In a scalar context,
the values are returned in a single string, and separated by a comma.
See createFrameElement() for details about the coordinates and size
units and notation.
=head3 getObjectDescription(object)
Returns the litteral description of a visible object. This method
makes sense for frames or frame-like objects (such as images or
text boxes).
=head3 getObjectSize(object)
Returns the size of the given object, if any. This method works with
frames and other frame-based objects, such as images and text boxes.
In the returned data, the width comes first, followed by the height.
The size is returned in the same way as the coordinates with
getObjectCoordinates().
=head3 getRoot()
Returns the absolute root element of the document. The root element
contains any other visible or non visible object, including the
document body (see getBody) and style definitions.
=head3 getText(path, position)
getText(element)
Returns text in the local character set, possibly UTF-8 decoded,
contained in the element given as an argument (by path/position or
by reference). See also getFlatText().
Two equivalent examples:
# version 1
my $element = $doc->getElement('//text:p', 4);
my $text = $doc->getText($element);
# version 2
my $text = $doc->getText('//text:p', 4);
Version 2 is better if the only aim is to get the text from
paragraph 4. Version 1 is better, however, if during the course of
the program you want to perform other operations on the same
paragraph. Giving an element's reference will mean avoiding element
handling methods having to recalculate a reference from the XPath
path.
getTextList(path)
Returns text from all elements in the specified path.
Example:
my $summary = $doc->getTextList('//text:h');
my $report = $doc->getTextList('//text:span');
The $summary variable contains a concatenation of all headers.
$report contains all the words or character strings that "stand out"
which the user has designated by their context, e.g. words in
italics in a non-italic paragraph.
In a list context, the returned data is a table, each of whose
elements contains the text of an XML element. In a scalar context
(as in our two examples), the returned value is a unique piece of
editable text and each element's content is separated from that of
the following element by a line feed.
getXMLContent([filehandle])
Without argument, returns a document's entire XML content.
Exports the entire XML content of the current member to a flat file,
if a file handle is provided.
Note: the exported data are UTF8-encoded.
Example:
open my $fh, ">:utf8", "myfile.xml";
$doc->getXMLContent($fh);
close $fh;
Synonym: exportXMLContent()
getXPathValue(xpath_expression)
A low-level method which allows direct access to the value
corresponding to the given XPath expression in a document. Character
decoding is handled in the same way as with getText.
Example:
$expression = '//office:automatic-styles' .
'/style:style' .
'[@style:style-name="P1"]' .
'/@style:parent-style-name';
print $doc->getXPathValue($expression);
This sequence displays the name of the parent style of automatic
style "P1" (if it exists within the document). Remember that more
simple methods in Text and/or Styles modules would indeed produce
the same result.
The optional element reference "context" can be given as an argument
either in first or second place. In this case, the search is limited
to the section of the document tree below this given element. The
default search area is the entire document.
Just as with other methods which require XPath paths, this one is
primarily for internal use. It should not be used by the majority of
applications.
Inserts a new element before or after the element specified by
[path, position] or by reference.
If the "name" argument is a literal, a new element with the name
given is created and then inserted. If the same argument is a
reference to an existing element, this element is then simply
inserted at the position indicated. This method is useful either for
adding new elements or for copying elements from one document to
another or from one position to another within the same document.
The position option allows you to choose the insertion point of the
new element. Possible values are "before", "after" and "within" (the
default is "before").
If "position" is set to "within", the new element is inserted within
the text of the target element, so an additional "offset" option (i.e.
a numeric position in the string) is required. Caution: this feature
is provided for a few special purposes only; inserting text elements
within text strings is not the same as inserting text strings within
text strings.
Other options are:
text => "text of element"
attribute => $attributes
The "attribute" (or "attributes") option is itself a hash reference
containing one or more attributes in the form [name => value] as in
appendElement.
When successful, this method returns the inserted element's
reference (else undef).
Example:
my $attributes =
{
'text:style-name' => 'Heading 2',
'text:level' => '2'
};
$doc->insertElement
(
'//text:p', 4, 'text:h',
position => 'after',
text => 'New section',
attribute => $attributes
);
This sequence (in a text document) inserts a level 2 header
'New section' immediately after paragraph 4.
The $name argument can be replaced by an existing element. In this
case a new reference to the existing element is inserted, without
creating a whole new element. In this way you can display an element
at several locations or in several documents which is held in memory
only once. See the appendElement section for the consequences of
having multiple references to the same physical element. Better to
use replicateElement to insert separate copies of an element.
In the same conditions as in appendElement, the 'name' argument can
be replaced by an XML string which describes the element.
Note: to add an element to the end of a document, it would obviously
be better to use appendElement.
isOpenDocument()
Returns 1 (true) if the current document is an OASIS Open Document.
To be used every time the application needs to know the format of
the document, knowing that some differences between the two formats
can't be completely hidden by the API.
Returns a special line break element, available for insertion within
an existing text element (knowing that "\n" is not recognized as a
line break if stored "as is"). The returned element is free, so it
could/should be inserted later within a text element.
makeXPath(expression)
Low-level method allowing the creation or direct modification
without restriction (almost) of any document element. It allows
"query" expressions in a language similar to XPath. If the given
XPath expression crosses several levels of hierarchy, intermediate
nodes can be created or modified "on the fly" by creating the
necessary path which in turn creates the final node.
Example:
$doc->makeXPath
(
'//office:body/text:p[4 @text:style-name="Text body"]'
);
This "query" applies the "Text body" style to paragraph 4 in the
body of the document. (In reality you will probably never use it
because the setStyle method of the Text module would do the same
thing much more simply.)
If, as in the above example, a node is accompanied by a position
indicator, it cannot be created but must simply act as a mandatory
"passage". This method cannot therefore be used to create, for
example, an Nth paragraph if there is already an N-1.
The only restrictions apply to namespaces which are given as
prefixes to element and attribute names. They must be defined in the
document i.e. conform to OpenDocument specifications. For the rest,
this method allows the creation of almost anything anywhere within a
document. Its use is reserved for OpenDocument XML specialists.
In its second form, a context node can be given as the first
argument. If present, the path is sought (and if necessary created)
starting from its position. By default, the path begins from the
root.
The returned value is the final node's reference (found or created).
The full "query language" syntax used in this method is not
documented here. makeXPath is designed to act more as a base for
other OpenOffice::OODoc methods than to be used in applications.
=head3 moveElements(target_element, element_list)
Moves a list of existing elements to a new attachment.
One more elements are cut from their previous place and appended
as children of the target element.
This method can be used to move elements from one place to another
place in the same document, as well as from one document to another
one (caution, the elements are moved, not copied).
Physically imports an external file into an OpenDocument archive
associated with an XPath object, if it exists i.e. if the object was
created using file or archive parameters. This method only transmits
the command to the OODoc::File's raw_import method. Caution: it must
not be used with an "active" element i.e. an XML member to which the
current XPath object or another XPath object is already associated.
Remember too that the import is not actually carried out by
OODoc::File until a save and the imported data is therefore not
immediately available.
Physically exports a member from an OpenDocument archive associated
with an XPath object, if it exists i.e. if the object was created
using file or archive parameters. This method only transmits the
command to the OODoc::File's raw_import method.
Deletes the "attribute" attribute (if found) of the given element by
[path, position] or by reference and returns "true". Has no physical
effect and returns undef if the attribute has not been defined or if
the element does not exist.
removeElement(element)
Deletes the given element (if found) by [path, position] or by
reference and returns "true". Returns undef if the element does not
exist.
Deletes the given element by [path, position] or by reference and
inserts another element in its place, either from another location
in the same document or from another document.
A new element can be supplied under the same conditions as for
insertElement.
By default or by using the mode => 'copy' option, it is a copy of
the new element which is inserted. With the mode => 'reference'
option, it is only a reference which is inserted. See the section on
appendElement for comments on the subject of multiple references to
a single physical element.
Replaces all sub-strings which match "filter" with "replacement" in
the text of an element (and its descendants) indicated by
[path, position] or by reference and returns the modified text. The
"filter" string can be an "exact" literal or a regular expression.
Example:
$doc->replaceText($p, "C(LIENT|USTOMER)", $contact);
replaces each occurrence of "CLIENT" and "CUSTOMER" with the content
of the $contact variable in the paragraph $p of document $doc.
The "replacement" argument can be a function reference. In which
case, the function is called each time the string is matched, and
the value returned by the function is used as the replacement value.
sub action {
my $arg = shift;
my $text = shift;
print "$arg : $text\n";
return "OK";
}
$doc->replaceText($p, $expression, \&action, "Found");
displays "Found: <text>" (where <text> is the text retrieved) each
time a string matches $expression and replaces this string with
"OK". If $expression contains an "exact" string (not a regexp), then
clearly the text displayed will always be the same string. However,
if it happens to be a regular expression, it is in effect the text
retrieved which will be displayed.
Generally speaking, if the replacement value is a function
reference, the called function receives the remainder of the
arguments which follow it, in this order:
1) all the arguments following the function reference in the
replaceText() call, in the same order;
2) the string that matches the filter argument.
See also substituteText(), which should be preferred in most
situations.
Makes a copy of the first given element and inserts it into the
current document at a position which depends on the second argument
and an optional parameter.
If the second argument is an existing object in the document, then
the copy is inserted according to an optional 'position' parameter:
- if no 'position' option is provided, then the copy is appended
as the last child of the position object;
- if 'position' => 'before' or 'after', then the copy is inserted at
the same hierarchical level as the position object, according to the
same logic as for insertElement().
If the second argument is not an object, but simply 'end', then the
new element is appended as the very last child of the physical root
of the document. See getRoot(). This option should generally be
avoided.
If the second argument is given as 'body', then the new element
is appended at the end of the document body (see getBody), as it was
created through appendElement().
Example:
my $template = $doc_source->selectElementByAttribute
(
'//style::style',
'style:name',
'Text body'
);
my $position = $doc_target->getElement
('//office:styles', 0);
$doc_target->replicateElement($template, $position);
This sequence adds a style 'Text body' to the style set of $doc_target
which copies exactly the style of the same name in $doc_source.
Obviously, the section of code dealing with the search for the element
to copy and its position is the most laborious. (In a real application,
thanks to OODoc::Styles, a more user-friendly coding would be allowed
for style replication.)
This method creates a new element which is an exact copy of the given
element, but which is physically separate from it.
This method is slower than simply modifying an existing element or
inserting an element reference.
If the user needs only a "free" copy of the element (out of the
document structure, to be later attached), the XML::Twig::Elt copy()
method should be preferred:
my $new_element = $old_element->copy;
resetCurrentContext()
Resets the search context to its default value, which is the root of
the document. See currentContext().
save([filename])
Saves the content of the current document through a physical
output.
The behaviour of this method depends on the way the current
OpenOffice::OODoc::XPath object has been created.
If the document is explicitly linked (through the 'file' option
of it's constructor) to a regular OOo or OpenDocument file, the
document is saved either in the source file, or (if a filename
is provided as an argument) in a new file.
If the document is linked to the same file interface as one or
more other OpenOffice::OODoc::XPath objects, the behaviour is
the same as in the previous case, but all the changes made by
all the linked objects are automatically saved in the target
file. Example:
my $content = odfXPath
(
file => 'source.odt',
part => 'content'
);
my $styles = odfXPath
(
container => $content,
part => 'styles'
)
my $meta = odfXPath
(
container => $content,
part => 'meta'
);
# ... a lot of content processing
# ... a lot of style processing
# ... a lot of metadata processing
$content->save('target.odt');
At the end of the sequence above, all the changes made through
the $content, $styles and $meta objects are saved in 'target.odt'
because these objects share a common file interface. Note that
in such a situation, the save() method can be issued from anyone
of the objects sharing the file interface (i.e. $content->save
could be replaced by $styles->save or $meta->save).
However, any XML part (content, styles, meta, ...) whose
'read_only' property is set to "true" is not saved. In the example
above, if, say, the $meta object is created (through odfXPath())
with a "read_only" option set to "true", only $content and $styles
are really saved by the last instruction.
Note: OpenOffice::OODoc::XPath doesn't really know anything about
the physical archive file; here save() is only a stub method and
the real job is done by the save() method of the associated container,
which is an OpenOffice::OODoc::File object.
If the document is not associated with a regular OpenDocument
compressed file (used through an OODoc::File object), it's saved
as "flat XML" to the given file. In such a situation, if the file name
is not provided, the source XML file (if any) is used as the target.
If the file is "flat XML", OODoc::XPath really effects the physical
output, without using any OODoc::File connector.
Note: if you need to save a document as flat XML while it's associated
with an OpenDocument file, you should use exportXMLContent() with an
application-provided file handle.
Returns the first (or only) element whose name matches "filter" from
within the child elements of the given element indicated by [path,
position] or by reference.
"filter" is taken to be a regular expression. If several values
match the filter, the first of these is returned (in the XML's
physical order which is not necessarily the logical order of the
document). See the comments about selectElementByAttribute if
wanting to select an exact name.
Returns undef if no elements match the condition.
Returns the first (or only) child (if there are more than one)
without anything else if no filter is given or if the filter uses
wildcards (".*").
Like selectChildElementByName, but returns a list of all elements
which match the condition.
Example:
my @search_words =
$doc->selectChildElementsByName
('//text:p', 4, 'text:span');
returns a list of elements from paragraph 4 which correspond to text
which has particular attributes which distinguish it from the rest
of the paragraph (colour, font, etc.)
Returns a list of elements corresponding to a given XPath path and
whose text matches the filter (regular expression). The "context"
argument, if given, is an element reference which limits the search
to its own child elements. The search is carried out in the entire
document by default.
An element is selected if the search string is found in its own text
or in the text of any element descended from it. E.g. An image
element (draw:image) can be selected from the value of its attached
"description" field.
You can replace all strings matching the search criteria with the
'replacement' string, on the fly, if the latter is given as an
argument after the filter.
Lastly, instead of a replacement string, you can pass a subroutine's
reference which will run (in call back mode) each time the search
string is matched. If this subroutine returns a defined value, this
value is used as the replacement string. The subroutine will
automatically receive the rest of the arguments, in this order:
Caution: this method can't retrieve a character string which is
split into more than one text element or text span. So, for example,
it will never retrieve "My String" as long as "My" and "String" are
presented with different styles, even if the two parts of the string
belong to the same paragraph.
If, as is generally the case, you are working exclusively with text
elements (paragraphs, headers, etc.), you would be better to use
selectElementsByContent() of the Text module which is easier to use
and does not require an XPath expression.
Here is an example which returns the list of images whose
descriptors contain the word "landscape" and displays the name of
each selected image:
sub printMessage
{
my $doc = shift;
my $element = shift;
my $image = $element->parentNode;
print "Name: " . $image->find('@draw:name') . "\n";
}
my @list = $doc->selectElements
(
'//draw:image/svg:desc',
'landscape',
\&printMessage,
$doc
);
Never use this example of code in a real application as it is both
purely for demonstration and unnecessarily complex. You can perform
the same operation much more simply using the OODoc::Image module.
In a list context, returns a list of elements at the given path with
the given attribute which contain a value matching the filter's
regular expression.
In a scalar context, returns the first (or only) element which
matches the same condition.
Returns undef if no elements match the condition.
Example:
my @paragraph_styles =
$doc->selectElementsByAttribute
('style:style', 'style:family', 'paragraph');
returns the list of elements which describe the paragraph styles of
document $doc.
Caution: the filter is treated as a regular expression and not as a
classic string. This means that the above piece of code might not
only return the elements whose "style:family" attribute equals
"paragraph", but also all those in which the same attribute contains
the word "paragraph". You must therefore use the appropriate syntax
(in regexp language) if you want to select an exact value, which in
this case would be "^paragraph$".
Like selectElementsByAttribute in a scalar context. Returns the
first (or only) element at the given path which has the given
attribute containing the given value.
Returns undef if no element matches the condition.
selectNodesByXPath(xpath_expression)
This low-level method returns a list of nodes (which are not
necessarily elements) which match the give XPath expression. See
getNodeByXPath() for options and comments.
Modifies or adds one or more attributes to an element.
The element is indicated by reference or by [path, position].
The list of attributes is given in the form of a hash name => value.
Example:
my $h = $doc->getElement('//text:h', 12);
my %attributes =
(
'text:style-name' => 'My Header',
'text:level => '3'
);
$doc->setAttributes($h, %attributes);
This sequence gives the 'My Header' style and level 3 to the 13th
"header" element in the document.
Like setText() described below, but without translation of "\t"
and "\n".
For exceptional use only. Allows, for example, the use of the OODoc
API with non-OpenDocument XML files.
Updates or creates the coordinates (X, Y) attributes of a visible
object (ex: image, text box, frame). See createFrameElement() for the
coordinates units and notation.
=head3 setObjectDescription(object, description)
Updates or creates the litteral description of the given object.
Should be used for frames, images or text boxes. Caution: the
description is not the same as the printable content of a text
box.
=head3 setObjectSize(object, size)
Updates or creates the width and height attributes of a given object.
This method makes sense for visible, rectangular objects only, such
as the frames, images or text boxes.
See createFrameElement() for details about the size units and
notation.
=head3 setText(path, position, text)
Uses the given text as the content of the given element.
Any previous content (including formatting markup, bookmarks,
notes, references, etc) is replaced by the given text.
If the given text includes tab stops ("\t") or line breaks ("\n"),
they are replaced by the appropriate OpenDocument tags. If this
translation must be avoided, use setFlatText() instead.
Note: The strings containing repeated spaces are not properly
processed. A sequence of repeated spaces, whatever its length,
is replaced by a single space in the target document. So
$doc->setText($p, "Begin End");
produces the same visible result as
$doc->setText($p, "Begin End");
See spaces() and extendText() for a workaround if you
need to insert repeated spaces.
=head3 spaces(length)
Returns a special element, available for insertion within a text
element, representing repeated contiguous blank spaces (knowing
that repeated spaces can't be properly displayed by an OpenDocument-
compliant application if stored as a flat string). The returned
element is free, so it could/should be inserted later within a text
element. See extendText() for an example of use.
Splits a text element at a given offset. This method is a wrapper
of the XML::Twig::Elt split_at() method, so, as said by Michel
Rodriguez in his documentation, it splits "a text element in 2" at
the given offset so "the original element now holds the first part
of the string and a new element holds the right part".
In addition, the new element is created with the same attributes (ex:
the style or the heading level, if any) as the original one.
The method returns both the original and the new elements in a list
context. In a scalar context, the new element only is returned.
The new element is "free", i.e. it doesn't belong to the document.
It's available for later use with any element attachment method,
provided by OpenOffice::OODoc (appendElement(), insertElement()) or
by XML::Twig (paste()). Example:
my $new_elt = $doc->splitElement($para, 12);
$doc->insertElement($para, $new_elt, position => 'after');
This example splits the given paragraph in two consecutive paragraphs.
Caution: splitElement() works properly on elements containing "flat
text" only. It's a bit complicated to use and probably doesn't
produce the right effects on elements containing line breaks, tab
stops, "styled spans" or any kind of structure. So, it should be used
on flat paragraphs or headings only.
=head3 substituteText(element, filter, replacement)
Replaces any substring in a given element and its descendants,
matching a given filter (regexp) by a given replacement string.
It "replacement" is a string, this method produces the same result as
replaceText(), and it should be preferred.
If "replacement" is a function reference, the replacement value is the
return value of the function. But, unlike replaceText(), any argument
after "replacement" is ignored.
This method is a wrapper for the subs_text() method provided by the
XML::Twig::Elt class. See the XML::Twig documentation for advanced
details.
Returns a special tabulation mark element, available for insertion
within an existing text element (knowing that "\t" is not recognized
as a tab stop if stored "as is"). The returned element is free, so
it could/should be inserted later within a text element.
=head2 Element methods
Every document element is an OpenOffice::OODoc::Element object,
and OpenOffice::OODoc::Element inherits all the rich features of
XML::Twig::Elt, including the very powerful copy(), cut(), paste(),
move() and replace() methods (look at the XML::Twig documentation
for details). Some additional methods, provided in the ::Element
package, are described below.
The "element methods" should be regarded as reserved for advanced
uses, possibly in combination with native XML::Twig::Elt methods
(not documented here, but the XML::Twig package itself is well
documented).
Remember these methods belong to the element and not to the
document...!
=head3 appendChild(newnode)
Appends a node as the last child of the calling node.
If the argument is an existing node, it's appended as is.
If the argument is a string, a new node is created, with the
given string as the XML tag name.
appendTextChild(text)
Appends a text node (PCDATA) as the last child of the calling
element.
flatten()
Converts in place the content of the calling element to a flat string,
removing any structure. All the children of the calling element are
removed and their text content is concatenated. The resulting string
becomes the only content of the element. For example, if the calling
element is a table, the tabular structure disappears and is replaced
by the concatenated contents of all the cells. Any possible internal
tab stop or line break element is removed, as well as any "styled"
text span (see setSpan() and removeSpan() is the OODoc::Text chapter
for information about styled text spans).
Be careful, a lot of elements are not displayed by the OpenDocument
compliant software. For example, a section element becomes invisible
if it directly contains its text, without structure elements such as
paragraphs, headings, tables, and so on. In order to make visible the
"flattened" content of a previously complex element, the XML tag
should be replaced by the tag of a "displayable" element. In the
following example, a section is flattened, then tagged as a
paragraph, so its content remains visible:
my $s = $doc->getSection("AnySection");
$s->flatten;
$s->set_tag('text:p');
Note: getSection() belongs to OpenOffice::OODoc::Text and set_tag()
is provided by the underlying XML::Twig::Elt package.
The text flattening is sometimes required in order to allow the
applications to retrieve strings which are split into more than one
text container. For example, a string such as "OpenDocument" can't
be retrieved using selectElements() or any other string search method
of the API if, say, "Open" and "Office" don't belong to the same text
span (i.e. if they have different styles; look at setSpan() in
OpenOffice::OODoc::Text to know more about text spans). In such a
situation, flatten() removes any text span markup, so the whole text
content of the element can be processed as a regular character string.
Caution, this method can produce terrific results when misused.
=head3 getLocalPosition([regexp])
Returns the position of the current element in the list of all
the children of the same parent with the same type.
Example:
$cell->getLocalPosition();
Assuming $cell is a table cell, this example returns the position
of the cell in the row without counting the covered cells (if any).
If a regular expression is provided as the optional argument, all
the siblings matching the expression are counted; but the method
returns zero if the calling element itself doesn't match the
expression.
Example:
$cell->getLocalPosition(qr'table:(covered-|)table-cell');
returns the position of the cell among all the cells (covered or not)
in the row.
Note: This method is a wrapper of the pos() method of XML::Twig::Elt,
but the returned values are zero-based in order to be consistent
with the other element addressing features of OpenOffice::OODoc.
Creates a new XML element, whose tag is passed as the 1st argument,
before, after or within the calling element. The 2nd argument
must be set to 'before', 'after', 'within', or any other value
accepted by the paste() method of XML::Twig. If the 2nd argument
is 'within', a 3rd one must be provided and indicate the offset.
=head3 replicateNode(count, position)
Produces one or more copies of the calling element and inserts
the copies before or after it. The position argument should be
'before' or 'after'; its default is 'after'. Technically, the
position argument could be anyone of the position options of
the XML::Twig::Elt->paste method, including 'first_child',
'last_child' or 'within'; but any other than 'before' and 'after'
probably don't make sense in an OpenDocument-compliant data
structure.
Without any argument, the calling element is replicated once.
But if the count argument is provided and set to zero or a
negative value, nothing is done.
Example :
my $row = $doc->getTableRow("Table1", -1);
$row->replicateNode(5);
This sequence appends 5 more rows to a table; each new row is a
copy of the last original row, including each individual cell
and its content.
=head3 selectChildElement(filter)
Like selectChildElements() below, but returns only the first node
matching the filter.
Note: the first_child() method of XML::Twig::Elt should be preferred
when the filter is the exact tag name of the needed element.
=head3 selectChildElements(filter)
Selects the children with XML tag names matching a given filter.
The filter is processed as a regexp.
Note: the children() method of XML::Twig::Elt should be preferred
if the filter is the exact tag name of the needed elements.
selectFrameElementByName(name)
Selects the first frame element whose name is exactly the given
argument. A frame is an OpenDocument container which can host a
rectangular object, such as an image or a text box.
=head2 Properties
No class variables are exported; the applications, if needed,
must access them using their full name ($OpenOffice::OODoc::XPath:XXX)
The following names should be prefixed explicitly with
"$OpenOffice::OODoc::XPath::"
CHARS_TO_ESCAPE
contains the list of reserved characters which, in XML, should be
replaced by escape sequences.
OO_CHARSET
indicates the character set used for OpenDocument document
encoding and whose default value is 'utf8' (it should not be changed).
LOCAL_CHARSET
indicates the user's character set, by default 'iso-8859-1'; it must
be changed according to the real user's needs (warning: there is no
kind of automatic adaptation to the user's locales, so the application
must explicitly load the right value in this variable); it should be
done using the odfLocalEncoding() accessor (see the OpenOffice::OODoc
man page and, for the list of supported character sets, the Encode
module's documentation).
The content of these three variables should not normally be directly
modified by the applications.
Instance hash variables are :
'container' => <oodoc_file_object>
'file' => <OpenDocument file>
'part' => <name of the XML part in the ODF package>
'readable_XML' => <'true' or 'false'>
'local_encoding' => <user's output encoding>
'element' => <name of loaded XML element>
'xpath' => <XML::Twig, XPath-capable object>
'twig_options' => <XML::Twig options as a hash reference>
'opendocument' => <'true' or 'false'>
However, the 'xml' variable is cleared almost immediately after a
successful constructor call, in order to save memory. As soon as the
corresponding XPath object has been created, the XML source is no
longer required.
The 'xpath' variable of an OODoc::XPath object contains a reference
to the document structure as it's made available through XML::Twig
(see CPAN documentation). This object encompasses the entire current
XML tree. Each access to XML using OODoc::XPath objects is done via
XML::Twig. So, after having run the following command:
my $xp = $doc->{'xpath'};
the experienced programmer will be able to use $xp to access all the
functionality of the XML::Twig API, bearing in mind that all
operations using this interface will have a direct effect on the
content of the $doc object.
'twig_options' allows the user to provide a hash reference of
additional options to XML::Twig. These options can modify the way the
document is parsed during the execution of odfXPath(). For special
applications only (see the XML::Twig reference manual).
The 'opendocument' property, if true, means that the document is
declared as an OASIS Open Document. If this property is false or
undef, the document format is OpenOffice.org version 1. This property
should not be changed (as long as OpenOffice::OODoc can't change the
format of an existing document).
Developer/Maintainer: Jean-Marie Gouarne http://jean.marie.gouarne.online.fr
Contact: jmgdoc@cpan.org
Copyright 2004-2008 by Genicorp, S.A. http://www.genicorp.com
Initial English version of the reference manual by Graeme A. Hunter (graeme.hunter@zen.co.uk)
License:
- Licence Publique Generale Genicorp v1.0
- GNU Lesser General Public License v2.1
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