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Comment Plugin

The Comment Plugin lets users quickly post comments to a page without an edit/preview/save cycle.

Related topics: CommentPluginTemplates, CommentPluginExamples


Inserts an edit box into the page that allows users to type in and save comments. Comments can be made

  • in different formats (as defined by a template),
  • in both forward and reverse chronological order,
  • signed or unsigned, dated or undated (as defined by a template),
  • in other topics, or other positions within the current topic.


Write %COMMENT{attributes}% anywhere in a TWiki topic.

  • A %COMMENT% without parameters shows a simple text box.
  • A %COMMENT{}% can handle the following parameters:
    Parameter Description Default
    type This is the name of the template to use for this comment. Comment templates are defined in a TWiki template - see customization. If this attribute is not defined, the type is whatever is defined by COMMENTPLUGIN_DEFAULT_TYPE, either in this topic or in your WebPreferences. "below"
    default Default text to put into the textarea of the prompt.  
    target Name of the topic to add the comment to the current topic
    location Regular expression specifying the comment location in the target topic. Read carefully the CommentPlugin documentation!  
    mode For compatibility with older versions only, synonymous with type  
    nonotify Set to "on" to disable change notification for target topics "off"
    noform Set to "on" to disable the automatic form that encloses your comment block - remember to insert <form> tags yourself! See CommentPluginExamples#noform for an example. "off"
    nopost Set to "on" to disable insertion of the posted text into the topic. "off"
    remove Set to "on" to remove the comment prompt after the first time it is clicked. "off"
    button Button label text "Add comment"
    emailto Send comment by email. Use comma "," to seperate multiple email addresses. This feature is disabled by default. To enable this feature, please set up "$TWiki::cfg{Plugins}{CommentPlugin}{EmailEnabled} = 1;".  

(See also additional attributes)

Positioning the comment

%COMMENT supports several ways to specify where a comment should be inserted in the target topic. This is referred to as the location of the comment.

Location relative to %COMMENT tag

The default location is the %COMMENT tag itself. For example:

will add comments in the current topic, directly below the %COMMENT tag.

Location relative to a TWiki anchor

The target attribute may specify a web, and may also specify an anchor within the target topic; for example,

%COMMENT{type="above" target="%USERSWEB%.PersonalRemarks#InsertHere"}%
This uses a standard TWiki in-topic anchor as the insertion location. See TextFormattingRules for more about TWiki anchors.

Location relative to an arbitrary text string

Getting more sophisticated, you can also specify a regular expression for the target location using the location parameter. The target topic is searched for the regular expression, and the comment inserted relative to the string that the search matched. For example,

%COMMENT{type="above" location="Flights of Fancy"}%
will place comments above the first occurrence of the string Flights of Fancy in the current topic.

Warning of course, if a user's comment contains the string "Flights of Fancy" they may and up changing the location for the next comment! Also, if you use a tag in the location, then you've just inserted another tag in the page that contains the %COMMENT! So be very careful how you specify the RE for location. Note that the RE is matched using perl "multiple line" mode, so ^ and $ match the start of a line and the end of a line respectively.
Also note that you cannot have the text location=" just before the location.

I look forward to someone leveraging this feature to create - for example - threaded conversations using %COMMENT.

If you specify an anchor and a location, the anchor will be ignored.

Default templates

Templates are used to define the "comment style" i.e. how comments appear in the page. The default is to add comments in "Blog like" style using bulleted lists, with the most recent comment at the top, but many other styles are available such as tables or Wiki thread mode comments. It is easy to define your own customer styles as well.

A set of default comment templates are shipped with the plugin - see also CommentPluginTemplates:

Template type Description
top Comments, signed and dated (server time), added at top of the topic (the anchor is ignored)
bottom Comments, signed and dated (server time), added at end of the target topic (the anchor is ignored)
above Comments, signed and dated (server time), added immediately before the target anchor, or the %COMMENT if no anchor is specified
below Comments, signed and dated (server time), added immediately below the target anchor, or the %COMMENT if no anchor is specified
belowthreadmode Comments, signed and dated, added recurse after comment box
threadmode Wiki thread mode comment, signed and dated (server time)
tableprepend Comments, signed and dated (server time), formatted as an HTML table row, added below the anchor (which must be in an HTML <table>)
tableappend Comments, signed and dated (server time), formatted as an HTML table row, added above the anchor (which must be in an HTML <table>)
action Action added to action table directly above comment box (see Plugin Installation Instructions below for important notes)
table Tablerows adding on end
toctalk Talk using TOC adding on end
bookmark Create a list of annotated bookmarks
return Post to a different topic and return

Your local installation may add more template types as well - see Customization, below.


Customization of the comment plugin requires

To define a comment type, you have to provide two simple template definitions in the template file; one for the prompt box, and one for the generated output. If we have a template type "mytype", these are named PROMPT:mytype and OUTPUT:mytype respectively. See comments.tmpl in the templates directory for examples.

The plugin picks up these template definitions from a standard TWiki template file, templates/comments.tmpl. This allows different templates to be defined for different TWiki skins.

Defining custom templates

By default, templates/comments.tmpl includes the topic CommentPluginTemplate, which contains all the shipped standard templates and in turn includes TWiki.UserCommentsTemplate that can include non-standard customizations.

This allows for several levels of customization:

  1. To override all default templates, everywhere, change comments.tmpl to include a different topic (this customization will be lost next time you upgrade, though).
  2. To add site-wide local template customizations, add them to UserCommentsTemplate (create if it does not exist yet). You can redefine the standard templates here if you want, and your definitions will override the standard definitions.
  3. To override templates on a web-by-web basis, add a topic UserCommentsTemplate to the web (this will replace TWiki.UserCommentsTemplate)
  4. To override templates for a specific skin, add them to TWiki.UserComments<Skin>Template (where <Skin> is the name of the skin with the first letter capitalized, e.g. Pattern)

Per topic custom comment template

You can also define a comment template in a topic, by passing the topic location with a templatetopic parameter. For example:

%COMMENT{type="blogpost" templatetopic="BlogPostCommentTemplate" target="%TOPIC%" button="Add comment" }%

templatetopic accepts topic or web.topic syntax. See an example in CommentPluginExamples#TemplateTopic.

If you use any topic other than UserCommentTemplate, it is critically important that you include this line at the end of your comment template topic:

Without this line your templates will not be picked up.

ALERT! Templates are picked up by following the standard TWiki rules for locating template files. Note that you can use %TMPL:INCLUDE% to include other files of templates.
ALERT! Note that from TWiki release 4.1.0 leading and trailing whitespace is no longer stripped. This means that when you upgrade to TWiki 4.1.X you may need to remove the first line break in your custom comment templates. See TWikiReleaseNotes04x01 for more information.

Customization example

Provide both a PROMPT and an OUTPUT definition:


Call your custom comment with:


The PROMPT template

The PROMPT template defines the contents of an HTML form that is used to capture the comment. This form invokes the comment generator when submitted. Parameters to the comment generator are defined using standard HTML input fields, such as input, textarea and select. The user enters values for these parameters, and these are then available when the OUTPUT template is expanded, in the form of %URLPARAM%s.

Note that you must define a "submit" button if you want the form to work!

Only the input fields of the form need be defined. The plugin automatically generates the <form> and </form> tags, with these two exceptions:

  1. The COMMENT has a noform="on" parameter. In this case, the PROMPT template has to specify the form tags and some additional hidden input fields. See CommentPluginExamples#noform example.
  2. The PROMPT template contains %COMMENTFORMSTART% and %COMMENTFORMEND%, which gives control over where to add the form tags and the hidden input fields:
    • %COMMENTFORMSTART% - HTML form start tag
    • %COMMENTFORMEND% - hidden input fields and HTML form end tag

The latter feature can be used to define a PROMPT template that contains more than one form, such as a comment plugin prompt form, and a second form with a "notify authors" button (see TWiki:Plugins.NotifyAuthorsPlugin).

Example PROMPT template with two forms:

%COMMENTFORMSTART% <!-- form start tag -->
<textarea %DISABLED% rows="%rows|5%" cols="%cols|80%" name="comment"></textarea>
<input %DISABLED% type="submit" value="%button|Add comment%" class="twikiButton" />
%COMMENTFORMEND% <!-- hidden input fields and form end tag -->
%NOTIFYAUTHORS% <!-- second form with notify authors button -->

Providing attribute values

If an attribute is given to the %COMMENT tag that is not one of the standard attributes, then that attribute is taken as the name of a parameter to be expanded in the PROMPT template. Expressions in the template of the form %param|default% (e.g. %rows|3%, %button|Push me%) are expanded to the values given in the %COMMENT. For example, if the PROMPT template 'example' contains:

<textarea rows=%rows|3% cols="%cols|50%" value="%tval|Rubbish%">
and the %COMMENT tag is:
%COMMENT{type="example" cols="75"}%
then the template will be expanded as
<textarea rows="3" cols="75" value="Rubbish">

Special variables

As well as support for all the usual TWiki variables in templates, the following special variables are supported in the PROMPT definition:

Variable Description
%DISABLED% Set to 'disabled' when you cannot comment (e.g. in preview mode).
%MESSAGE% The text specified by default. This may be overridden by a helpful message when the prompt is DISABLED.

EXPERT Note that when a comment is saved, the TWiki save script is invoked on the target topic, with a number of parameters provided by the comment form. Normally the CommentPlugin will provide these fields in the form, but experts can also provide the fields themselves in order to get finer control over what is submitted, or you might want to define your own HTML forms that do comment submission. The parameters that the CommentPlugin recognises are as follows:

CGI parameter Description
comment_action Must be save to get the CommentPlugin to perform
comment_type Type of the OUTPUT template
comment_index Zero-based index of the %COMMENT in the source topic. Used to place a post relative to an existing %COMMENT.
comment_anchor Anchor taken from the target spec
comment_location As passed to %COMMENT
comment_nonotify As passed to %COMMENT
comment_remove Zero-based index of a %COMMENT to remove from the target topic
comment_nopost As passed to %COMMENT
comment_templatetopic As passed to %COMMENT
Note that comment_location overrides comment_anchor, and both override comment_index. Example, shows an "I Approve" button that adds your approval signature to the end of the topic:
<form method="post" action="%SCRIPTURL{save}%/%WEB%/%TOPIC%">
<input type="submit" value="I Approve" />
<input type="hidden" name="comment_action" value="save" />
<input type="hidden" name="comment_type" value="bottom" />
<input type="hidden" name="comment" value="I Approve" />

Customization example with custom form template

Write a custom form in a topic.

  • In the form set the location of the prompt with %COMMENTPROMPT%; the prompt will be positioned here.
  • In %COMMENT use parameter noform="on"
  • In %COMMENT use parameter templatetopic to point to the topic with the form template

Example form:

<form method="post" action="%SCRIPTURL{save}%/%BASEWEB%/%BASETOPIC%" enctype="application/x-www-form-urlencoded" name="examplecomment" id="examplecomment">
<input type="hidden" name="redirectto" value="%BASEWEB%.%BASETOPIC%" />

Example comment:

%COMMENT{noform="on" type="example" templatetopic="Sandbox.CommentPluginTemplateExample" target="%TOPIC%" button="Add comment" }%

The OUTPUT template

The OUTPUT template defines the format for the text that actually gets embedded into the topic. All the usual TWiki variables are available in the PROMPT definition, but note that they get expanded when the comment is inserted in the text, so time, date and username will refer to the time and date when the comment was made, and the user who made it.

There are also four position tags that are used to indicate where the comment should be placed, relative to the location defined in the %COMMENT tag:

%POS:TOP% If present, comments will be inserted at the top of the topic i.e. before any other text
%POS:BOTTOM% If present, comments will be inserted at the end of the topic i.e. after all existing text
%POS:BEFORE% If present, comments will be inserted immediately before the %COMMENT% tag
%POS:AFTER% If present, comments will be inserted immediately after the %COMMENT% tag

Note that these position tags are obviously mutually exclusive. If you define more than one, the result is undefined. If none is present, the default is taken from the plugin setting COMMENTPLUGIN_DEFAULT_TYPE

%COMMENTPROMPT% Use with a custom form. If present, the comment prompt will be positioned here.

All the usual TWikiVariables that can be used in a topic template can also be used in an OUTPUT template. See TWikiVariables for details.

Plugin Settings

Plugin settings are stored as preferences settings. Do not change the settings here, they are here only for illustration purposes showing the default values. Define the settings in Main.TWikiPreferences, in a WebPreferences or in individual topics. For example, to customize the COMMENTPLUGIN_DEFAULT_TYPE setting, add a * Set COMMENTPLUGIN_DEFAULT_TYPE = ... bullet in Main.TWikiPreferences.

  • Name of file in the twiki/templates directory that contains the comment templates. The default 'comments.tmpl' automatically includes user templates from TWiki.CommentPluginTemplate, which in turn includes TWiki.UserCommentsTemplate.

  • Default template type (above or below) :

Plugin Installation Instructions

This plugin is pre-installed. TWiki administrators can upgrade the plugin as needed on the TWiki server.

  • For an automated installation, run the configure script and follow "Find More Extensions" in the in the Extensions section.

  • Or, follow these manual installation steps:
    • Download the ZIP file from the extension home on twiki.org (see below).
    • Unzip CommentPlugin.zip in your twiki installation directory.
    • Set the ownership of the extracted directories and files to the webserver user.
    • Install the dependencies (if any).

  • Plugin configuration and testing:
    • Run the configure script and enable the plugin in the Plugins section.
    • Configure additional plugin settings in the Extensions section if needed.
    • Test if the installation was successful using the examples provided.

Note that if you want to use the action template then you must also:

  1. Install the TWiki:Plugins/ActionTrackerPlugin;
  2. Put the CommentPlugin before the ActionTrackerPlugin in the {PluginsOrder} configuration option (in configure)

Plugin Info

  • Set SHORTDESCRIPTION = Quickly post comments to a page without an edit/preview/save cycle.

Plugin Author: TWiki:Main.CrawfordCurrie http://www.c-dot.co.uk inspired by the work of TWiki:Main.DavidWeller and TWiki:Main.PeterMasiar
Copyright: © 2004, TWiki:Main.CrawfordCurrie;
© 2009 TWiki:Main.SopanShewale;
© 2004-2015 TWiki:Main.PeterThoeny;
© 2004-2015 TWiki:TWiki.TWikiContributor
License: GPL (GNU General Public License)
Plugin Version: 2015-01-10
2015-01-10: TWikibug:Item7604: Switch to GPL v3
2013-02-10: TWikibug:Item7141: Control over where to add the form tag in comment PROMPT template -- TWiki:Main.PeterThoeny
2013-02-06: TWikibug:Item7139: Use BUBBLESIGNATUREFORMAT if defined, showing nice bubble boxes around around default comments -- TWiki:Main.PeterThoeny
2013-01-09: TWikibug:Item7123: Use TWISTY in plugin settings section, installation instructions and change history
2013-01-04: TWikibug:Item7115: Configurable signatures with profile pictures - use SIGNATUREFORMAT setting in default comment box signature -- TWiki:Main.PeterThoeny
2012-11-16: TWikibug:Item7039: Adapting it to the enhnaced TWiki::Func::getScriptUrl() -- TWiki:Main.HideyoImazu
2012-11-12: TWikibug:Item6967: Better layout of default comment box -- TWiki:Main.PeterThoeny
2012-11-11: TWikibug:Item7020: Categorize TWiki Variable COMMENT -- TWiki:Main.PeterThoeny
2012-09-26: TWikibug:Item6945: Send comment to multiple email addresses.
2012-09-26: TWikibug:Item6944: Get script URL with TWiki::Func::getMasterWebScriptUrl.
2011-06-16: TWikibug:Item6754: Fix for action comment template missing %ENDACTION% -- TWiki:Main.JohnRouillard
2011-06-12: TWikibug:Item6725: Change global package variables from "use vars" to "our"; adding NO_PREFS_IN_TOPIC in plugin package -- TWiki:Main.PeterThoeny
2011-03-28: TWikibug:Item6672 - doc improvements: Adding link to HIDE
2010-12-11: TWikibug:Item6530 - doc improvements -- TWiki:Main.ScottGutman
2010-05-16: TWikibug:Item6433 - doc improvements
2010-03-19 TWikibug:Item6404 Use $br in newline parameter for break tag instead of turning off encoding -- TWiki:Main/PeterThoeny
2010-02-27 TWikibug:Item6276 Cannot specify percentBRpercent for newline value -- TWiki:Main/SopanShewale
2009-01-21 TWikibug:Item6163 Fix for Comment Plugin losing data if target anchor is missing -- TWiki:Main/TimotheLitt and TWiki:Main/SopanShewale
03 Aug 2008 The TWiki 4.2.1 release version
11 Apr 2008 TWikibug:Item5518 corrected the template definition for bulletabove
5 Sep 2007 TWikibug:Item3689 corrected location handling TWikibug:Item4181 added VarCOMMENT TWikibug:Item4402 corrected access check
22 Jun 2007 Removed the long-deprecated %TIME (use %GMTIME instead). Minor doc changes
14021 TWikibug:Item3755 Fixed incorrect handling of line terminators when targeting an anchor
13311 Added option to define a comment template in any topic. Pass the topic location with templatetopic (either topic or web.topic). See an example in CommentPluginExamples:templatetopic.
12822 TWikibug:Item3598 minor doc fixes
12750 TWikibug:Item3510 added a note about the changed template spec in TWiki 4.1.0. Code remains unchanged
11358 TWikibug:Item2802 moved SHORTDESCRIPTION to .pm. Coded up TWiki:Main/PankajPant's suggestions as nopost and remove. Added default text for the %COMMENT as requested by TWiki:Main.AndyGlew
11118 TWikibug:Item2322 removed span tag around oneliner bullet output
8788 TWikibug:Item1465 Item1577: reverted 8433 to fix inclusion of correct user templates
8787 TWikibug:Item1573 renamed standard templates topic to avoid naming clash on Windows, where filenames are case-insensitive
8433 TWikibug:Item1465 Fix 'TWiki.' to '%TWIKIWEB%.'; also fixed include 'UserComments' to 'UserCommentsTemplate' (at least that is what the doc suggests)
7427 TWikibug:Item845 removed duplicate date in default comments; stick with server time
7251 TWikibug:Item810 fix for user template inclusion; reorganised templates to make customisation easier
5906 TWikibug:Item143 apache warning from comment plugin when CommentsTmpl.txt not found
5519 CommentPluginOnAnchorsBroken: incorporated JacobEisinger's fix
5518 CommentPluginOnAnchorsBroken: incorporated OlivierBerger's fix
5455 On Niels Kodslo's prompting, removed the global recursion prevention that I believe is no longer needed.
5280 Removed templates, and some minor fixes
5250 Removed newlines from prompt box
4902 Changed to use viewauth. Moved templates into user topics.
4901 Added templates in user webs support
4897 Fixes for disabling during preview; re-enabled old legacy parameters
4889 Chopped down from PeterMasiar version, removing several parameters, savecomment script, changing way templates are done. Major rewrite, atcherly.
4882 Update from PeterMasiar's 2.0 version, plus documentation and small code improvements.
4745 06 Mar 2002 initial commit
Plugin Home: http://TWiki.org/cgi-bin/view/Plugins/CommentPlugin
Feedback: http://TWiki.org/cgi-bin/view/Plugins/CommentPluginDev
Appraisal: http://TWiki.org/cgi-bin/view/Plugins/CommentPluginAppraisal

Related Topics: CommentPluginTemplates, CommentPluginExamples, TWikiPreferences, TWikiPlugins

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Topic revision: r22 - 2015-01-11 - TWikiContributor
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