%TOC% %STARTINCLUDE% <a name="MetaDataDefinition"></a> # <a name="TWiki_Meta_Data"> TWiki Meta Data </a> _Additional topic data, program-generated or from [[TWikiForms]], is stored in `META` variable name/value pairs_ ## <a name="Overview"> Overview </a> [[TWikiMetaData]] uses `META` variables to store topic data that's separate from the main free-form content. This includes program-generated info like [[FileAttachment]] and topic movement data, and user-defined [[TWikiForms]] info. Use `META` variables to format and display Meta Data. ## <a name="Meta_Data_Syntax"> Meta Data Syntax </a> * Format is the same as in [[TWikiVariables]], except all fields have a key. * <code>%META:<type>\{key1="value1" key2="value2" ...\}%</code> * Order of fields within the meta variables is not defined, except that if there is a field with key `name`, this appears first for easier searching (note the order of the variables themselves is defined). * Each meta variable is on one line. * `\n` (new line) is represented in values by <code>%\_N\_</code> and `"` (double-quotes) by <code>%\_Q\_%</code>. > **Example of Format** > > <pre> > %<nop>META:TOPICINFO{version="1.6" date="976762663" author="PeterThoeny" format="1.0"}% > text of the topic > %<nop>META:TOPICMOVED{from="Codev.OldName" to="Codev.NewName" > by="JohnTalintyre" date="976762680"}% > %<nop>META:TOPICPARENT{name="NavigationByTopicContext"}% > %<nop>META:FILEATTACHMENT{name="Sample.txt" version="1.3" ... }% > %<nop>META:FILEATTACHMENT{name="Smile.gif" version="1.1" ... }% > %<nop>META:FORM{name="WebFormTemplate"}% > %<nop>META:FIELD{name="OperatingSystem" value="OsWin"}% > %<nop>META:FIELD{name="TopicClassification" value="PublicFAQ"}% > </nop></nop></nop></nop></nop></nop></nop></nop></pre> ## <a name="Meta_Data_Specifications"> Meta Data Specifications </a> The current version of Meta Data is 1.0, with support for the following variables. ### <a name="META_TOPICINFO"> </a> META:TOPICINFO <table border="1" cellpadding="1" cellspacing="0"> <tr> <th align="center" bgcolor="#99CCCC"><strong>Key</strong></th> <th align="center" bgcolor="#99CCCC"><strong>Comment</strong></th> </tr> <tr> <td> version </td> <td> Same as RCS version </td> </tr> <tr> <td> date </td> <td> integer, unx time, seconds since start 1970 </td> </tr> <tr> <td> author </td> <td> last to change topic, is the REMOTE_USER </td> </tr> <tr> <td> format </td> <td> Format of this topic, will be used for automatic format conversion </td> </tr> </table> ### <a name="META_TOPICMOVED"> </a> META:TOPICMOVED This is optional, exists if topic has ever been moved. If a topic is moved more than once, only the most recent META:TOPICMOVED meta variable exists in the topic, older ones are to be found in the rcs history. <code>%META:TOPICMOVED\{from="Codev.OldName" to="Codev.NewName" by="talintj" date="976762680"\}%</code> <table border="1" cellpadding="1" cellspacing="0"> <tr> <th align="center" bgcolor="#99CCCC"><strong>Key</strong></th> <th align="center" bgcolor="#99CCCC"><strong>Comment</strong></th> </tr> <tr> <td> from </td> <td> Full name i.e. web.topic </td> </tr> <tr> <td> to </td> <td> Full name i.e. web.topic </td> </tr> <tr> <td> by </td> <td> Who did it, is the REMOTE_USER, not <nop>WikiName </nop></td> </tr> <tr> <td> date </td> <td> integer, unx time, seconds since start 1970 </td> </tr> </table> Notes: * at present version number is not supported directly, it can be inferred from the RCS history. * there is only one META:TOPICMOVED in a topic, older move information can be found in the RCS history. ### <a name="META_TOPICPARENT"> </a> META:TOPICPARENT <table border="1" cellpadding="1" cellspacing="0"> <tr> <th bgcolor="#99CCCC"><strong>Key</strong></th> <th bgcolor="#99CCCC"><strong>Comment</strong></th> </tr> <tr> <td> name </td> <td> The topic from which this was created, <span style="background:"><font color="">Web Home</font></span><a href="http://LOCATION/WebHome">?</a> if done from <code>Go</code>, othewise topic where <code>?</code> or form used. Normally just topic, but is full web.topic format if parent is in a different Web. Renaming a Web will then only break a few of these references or they can be scanned and fixed. </td> </tr> </table> ### <a name="META_FILEATTACHMENT"> </a> META:FILEATTACHMENT <table border="1" cellpadding="1" cellspacing="0"> <tr> <th bgcolor="#99CCCC"><strong>Key</strong></th> <th bgcolor="#99CCCC"><strong>Comment</strong></th> </tr> <tr> <td> name </td> <td> Name of file, no path. Must be unique within topic </td> </tr> <tr> <td> version </td> <td> Same as RCS revision </td> </tr> <tr> <td> path </td> <td> Full path file was loaded from </td> </tr> <tr> <td> size </td> <td> In bytes </td> </tr> <tr> <td> date </td> <td> integer, unx time, seconds since start 1970 </td> </tr> <tr> <td> user </td> <td> the REMOTE_USER, not <nop>WikiName </nop></td> </tr> <tr> <td> comment </td> <td> As supplied when file uploaded </td> </tr> <tr> <td> attr </td> <td><code>h</code> if hidden, optional </td> </tr> </table> Extra fields that are added if an attachment is moved: <table border="1" cellpadding="1" cellspacing="0"> <tr> <th bgcolor="#99CCCC"><strong>Key</strong></th> <th bgcolor="#99CCCC"><strong>Comment</strong></th> </tr> <tr> <td> movedfrom </td> <td> full topic name - web.topic </td> </tr> <tr> <td> movedby </td> <td> the REMOTE_USER, not <nop>WikiName </nop></td> </tr> <tr> <td> movedto </td> <td> full topic name - web.topic </td> </tr> <tr> <td> moveddate </td> <td> integer, unx time, seconds since start 1970 </td> </tr> </table> ### <a name="META_FORM"> </a> META:FORM <table border="1" cellpadding="1" cellspacing="0"> <tr> <th bgcolor="#99CCCC"><strong>Key</strong></th> <th bgcolor="#99CCCC"><strong>Comment</strong></th> </tr> <tr> <td> name </td> <td> A topic name - the topic represents one of the <span style="background:"><font color="">TWiki Forms</font></span><a href="http://LOCATION/TWikiForms">?</a>. Can optionally include the web name i.e. web.topic, but doesn't normally </td> </tr> </table> ### <a name="META_FIELD"> </a> META:FIELD Should only be present if there is a META:FORM entry. Note that this data is used when viewing a topic, the form template definition is not read. <table border="1" cellpadding="1" cellspacing="0"> <tr> <th bgcolor="#99CCCC"><strong>Key</strong></th> <th bgcolor="#99CCCC"><strong>Name</strong></th> </tr> <tr> <td> name </td> <td> Ties to entry in <span style="background:"><font color="">TWiki Forms</font></span><a href="http://LOCATION/TWikiForms">?</a> template, is title with all bar alphanumerics and . removed </td> </tr> <tr> <td> title </td> <td> Full text from <span style="background:"><font color="">TWiki Forms</font></span><a href="http://LOCATION/TWikiForms">?</a> template </td> </tr> <tr> <td> value </td> <td> Value user has supplied via form </td> </tr> </table> ### <a name="Recommended_Sequence"> Recommended Sequence </a> There is no absolute need for Meta Data variables to be listed in a specific order within a topic, but it makes sense to do so a couple of good reasons: * form fields remain in the order they are defined * the `diff` function output appears in a logical order The recommended sequence is: * META:TOPICINFO * `text of topic` * META:TOPICMOVED (optional) * META:TOPICPARENT (optional) * META:FILEATTACHMENT (0 or more entries) * META:FORM (optional) * META:FIELD (0 or more entries; FORM required) ## <a name="Viewing_Meta_Data_in_Page_Source"> Viewing Meta Data in Page Source </a> When viewing a topic the <code>**Raw Text**</code> link can be clicked to show the text of a topic (ie: as seen when editing). This is done by adding `raw=on` to URL. `raw=debug` shows the meta data as well as the topic data, ex: [debug view for this topic](%SCRIPTURLPATH%/view%SCRIPTSUFFIX%/%WEB%/%TOPIC%?raw=debug) <a name="MetaDataRendering"></a> ## <a name="Rendering_Meta_Data"> Rendering Meta Data </a> Meta Data is rendered with the %META% variable. This is mostly used in the `view`, `preview` and `edit` scripts. Current support covers: <table border="1" cellpadding="1" cellspacing="0"> <tr> <th bgcolor="#99CCCC"><strong>Variable usage:</strong></th> <th bgcolor="#99CCCC"><strong>Comment:</strong></th> </tr> <tr> <td> %<nop>META{"form"}% </nop></td> <td> Show form data, see <span style="background:"><font color="">TWiki Forms</font></span><a href="http://LOCATION/TWikiForms">?</a></td> </tr> <tr> <td> %<nop>META{"attachments"}% </nop></td> <td> Show attachments, exclude hidden </td> </tr> <tr> <td> Options for <span style="background:"><font color="">Attachments</font></span><a href="http://LOCATION/FileAttachments">?</a>: </td> <td> </td> </tr> <tr> <td> all="on" </td> <td> Show ALL attachments (including hidden) </td> </tr> <tr> <td> %<nop>META{"moved"}% </nop></td> <td> Details of any topic moves </td> </tr> <tr> <td> %<nop>META{"parent [options]"}% </nop></td> <td> Show topic parent </td> </tr> <tr> <td> Options for parent: </td> <td> </td> </tr> <tr> <td> dontrecurse="on" </td> <td> By default recurses up tree, at some cost </td> </tr> <tr> <td> prefix="..." </td> <td> Prefix for parents, only if there are parents; default "" </td> </tr> <tr> <td> suffix="..." </td> <td> Suffix, only appears if there are parents; default "" </td> </tr> <tr> <td> separator="..." </td> <td> Separator between parents, default is " &gt; " </td> </tr> </table> ## <a name="Known_Issues"> Known Issues </a> At present, there is no Meta Data support for Plugins. However, the format is readily extendable and the `Meta.pm` code that supports the format needs only minor alteration. -- [[JohnTalintyre]] - 29 Aug 2001 <br /> -- [[MikeMannix]] - 03 Dec 2001