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, 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, 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, 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 |
Comment |
movedfrom |
full topic name - web.topic |
movedby |
the REMOTE_USER, not WikiName |
movedto |
full topic name - web.topic |
moveddate |
integer, unix 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.
Note: Rendering meta data is currently not supported in topic text. As a workaround, use
FormattedSearch on the current topic only to render form fields.
Current support covers:
Variable usage: |
Comment: |
%META{"moved"}% |
Details of any topic moves. |
%META{"attachments"}% |
Show attachments, except for hidden ones. Options: all="on" : Show all attachments, including hidden ones. |
%META{"form"}% |
Show form data, see TWikiForms. |
%META{"formfield"}% |
Show form field value. Parameter: name="field_name" . Example: %META{ "formfield" name="TopicClassification" }% |
%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.
--
TWiki:Main.JohnTalintyre - 29 Aug 2001
--
TWiki:Main.MikeMannix - 03 Dec 2001
--
TWiki:Main.PeterThoeny - 10 Jan 2002