TWiki Meta Data
Additional topic data, program-generated or from TWikiForms, is stored in META variable name/value pairs
Overview
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.
Meta Data Syntax
- Format is the same as in TWikiVariables, except all fields have a key.
-
%META:<type>{key1="value1" key2="value2" ...}%
- 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 %_N_ and " (double-quotes) by %_Q_%.
Example of Format
%META:TOPICINFO{version="1.6" date="976762663" author="PeterThoeny" format="1.0"}%
text of the topic
%META:TOPICMOVED{from="Codev.OldName" to="Codev.NewName"
by="JohnTalintyre" date="976762680"}%
%META:TOPICPARENT{name="NavigationByTopicContext"}%
%META:FILEATTACHMENT{name="Sample.txt" version="1.3" ... }%
%META:FILEATTACHMENT{name="Smile.gif" version="1.1" ... }%
%META:FORM{name="WebFormTemplate"}%
%META:FIELD{name="OperatingSystem" value="OsWin"}%
%META:FIELD{name="TopicClassification" value="PublicFAQ"}%
Meta Data Specifications
The current version of Meta Data is 1.0, with support for the following variables.
META:TOPICINFO
| Key | Comment |
|---|
| version | Same as RCS version |
| date | integer, unx time, seconds since start 1970 |
| author | last to change topic, is the REMOTE_USER |
| format | Format of this topic, will be used for automatic format conversion |
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.
%META:TOPICMOVED{from="Codev.OldName" to="Codev.NewName" by="talintj" date="976762680"}%
| Key | Comment |
|---|
| from | Full name, i.e., web.topic |
| to | Full name, i.e., web.topic |
| by | Who did it, is the REMOTE_USER, not WikiName |
| date | integer, unx time, seconds since start 1970 |
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.
META:TOPICPARENT
| Key | Comment |
|---|
| name | The topic from which this was created, WebHome if done from Go, othewise topic where ? 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. |
META:FILEATTACHMENT
| Key | Comment |
|---|
| name | Name of file, no path. Must be unique within topic |
| version | Same as RCS revision |
| path | Full path file was loaded from |
| size | In bytes |
| date | integer, unx time, seconds since start 1970 |
| user | the REMOTE_USER, not WikiName |
| comment | As supplied when file uploaded |
| attr | h if hidden, optional |
Extra fields that are added if an attachment is moved:
| Key | Comment |
|---|
| movedfrom | full topic name - web.topic |
| movedby | the REMOTE_USER, not WikiName |
| movedto | full topic name - web.topic |
| moveddate | integer, unx time, seconds since start 1970 |
META:FORM
| Key | Comment |
|---|
| name | A topic name - the topic represents one of the TWikiForms. Can optionally include the web name (i.e., web.topic), but doesn't normally |
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.
| Key | Name |
|---|
| name | Ties to entry in TWikiForms template, is title with all bar alphanumerics and . removed |
| title | Full text from TWikiForms template |
| value | Value user has supplied via form |
Recommended Sequence
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)
Viewing Meta Data in Page Source
When viewing a topic the
Raw Text link can be clicked to show the text of a topic (i.e., 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
Rendering Meta Data
Meta Data is rendered with the %META% variable. This is mostly used in the
view,
preview and
edit scripts.
Current support covers:
| Variable usage: | Comment: |
|---|
%META{"form"}% | Show form data, see TWikiForms. |
%META{"attachments"}% | Show attachments, except for hidden ones. Options:
all="on": Show all attachments, including hidden ones. |
%META{"moved"}% | Details of any topic moves. |
%META{"parent"}% | Show topic parent. Options:
dontrecurse="on": By default recurses up tree, at some cost.
nowebhome="on": Suppress WebHome.
prefix="...": Prefix for parents, only if there are parents, default "".
suffix="...": Suffix, only appears if there are parents, default "".
separator="...": Separator between parents, default is " > ". |
Known Issues
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
--
MikeMannix? - 03 Dec 2001
--
PeterThoeny - 10 Jan 2002
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