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TWiki Meta Data

Additional topic data, program-generated or from TWikiForms, is stored embedded in the topic text using META: tags

Overview

By default, TWiki stores topics in files on disk, in a really simple and obvious directory structure. The big advantage of this approach is that it makes it really easy to manipulate topics from outside TWiki, and is also very safe; there are no complex binary indexes to maintain, and moving a topic from one TWiki to another is as simple as copying a couple of text files.

To keep everything together in one place, TWiki uses a simple method for embedding additional data (program-generated or from TWikiForms) in topics. It does this using META: tags.

META: data includes program-generated info like FileAttachment and topic movement data, and user-defined TWikiForms info.

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.

  • Values in meta-data are URL encoded so that characters such as \n can be stored.

Example of Format
%META:TOPICINFO{version="1.6" date="976762663" author="LastEditorWikiName" format="1.0"}%
   text of the topic
%META:TOPICMOVED{from="Codev.OldName" to="Codev.NewName"
   by="TopicMoverWikiName" 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, unix 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, unix 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, typically when clicking on a red-link, or by filling out a form. Normally just TopicName, but it can be a full Web.TopicName format if the parent is in a different Web.

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, unix 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