data/TWiki/TWikiTemplatesDotPm.txt
author Colas Nahaboo <colas@nahaboo.net>
Sat, 26 Jan 2008 15:50:53 +0100
changeset 0 414e01d06fd5
permissions -rw-r--r--
RELEASE 4.2.0 freetown
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---+ Package =TWiki::Templates=
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Support for the TWiki template language.
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%TOC%
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The following tokens are supported by this language:
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| %<nop>TMPL:P% | Instantiates a previously defined template |
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| %<nop>TMPL:DEF% | Opens a template definition |
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| %<nop>TMPL:END% | Closes a template definition |
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| %<nop>TMPL:INCLUDE% | Includes another file of templates |
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Note; the template cache does not get reset during initialisation, so
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the haveTemplate test will return true if a template was loaded during
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a previous run when used with mod_perl or speedycgi. Frustrating for
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the template author, but they just have to switch off
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the accelerators during development.
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This is to all intents and purposes a singleton object. It could
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easily be coverted into a true singleton (template manager).
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---++ ClassMethod *new* <tt>($session)</tt>
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Constructor. Creates a new template database object.
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   * $session - session (TWiki) object
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---++ ObjectMethod *finish* <tt>()</tt>
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Break circular references.
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---++ ObjectMethod *haveTemplate* <tt>($name) -> $boolean</tt>
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Return true if the template exists and is loaded into the cache
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---++ ObjectMethod *expandTemplate* <tt>($params) -> $string</tt>
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Expand the template specified in the parameter string using =tmplP=.
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Examples:
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<verbatim>
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$tmpls->expandTemplate('"blah");
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$tmpls->expandTemplate('context="view" then="sigh" else="humph"');
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---++ ObjectMethod *tmplP* <tt>($attrs) -> $string</tt>
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Return value expanded text of the template, as found from looking
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in the register of template definitions. The attrs can contain a template
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name in _DEFAULT, and / or =context=, =then= and =else= values.
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Recursively expands any contained TMPL:P tags.
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Note that it would be trivial to add template parameters to this,
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simply by iterating over the other parameters (other than _DEFAULT, context,
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then and else) and doing a s/// in the template for that parameter value. This
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would add considerably to the power of templates. There is already code
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to do this in the MacrosPlugin.
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---++ ObjectMethod *readTemplate* <tt>($name,$skins,$web) -> $text</tt>
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Return value: expanded template text
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Reads a template, constructing a candidate name for the template thus
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   0 looks for file =$name.$skin.tmpl= (for each skin)
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      0 in =templates/$web=
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      0 in =templates=, look for
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   0 looks for file =$name.tmpl=
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      0 in =templates/$web=
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      0 in =templates=, look for
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   0 if a template is not found, tries in this order
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      0 parse =$name= into a web name (default to $web) and a topic name and looks for this topic
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      0 looks for topic =${skin}Skin${name}Template= 
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         0 in $web (for each skin)
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         0 in =TWiki::cfg{SystemWebName}= (for each skin)
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      0 looks for topic =${name}Template=
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         0 in $web (for each skin)
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         0 in =TWiki::cfg{SystemWebName}= (for each skin)
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In the event that the read fails (template not found, access permissions fail)
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returns the empty string ''.
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=$skin=, =$web= and =$name= are forced to an upper-case first character
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when composing user topic names.
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If template text is found, extracts include statements and fully expands them.
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Also extracts template definitions and adds them to the
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list of loaded templates, overwriting any previous definition.
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