# Comment Plugin **Comment Plugin lets users quickly post comments to a page without an edit/preview/save cycle.**
On this page:
Related topics: [[CommentPluginTemplates]], [[CommentPluginExamples]]
WARNING: TWiki-4 only. If you want to use this plugin with an earlier version of TWiki, please use revision 31 of the zip.
## Features 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. ## Syntax Write %COMMENT\{_attributes_\}% anywhere in a TWiki topic. (See also [[additional attributes|Main/WebHome#MoreAttrs]]) ### 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: %COMMENT{type="below"}% 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="%MAINWEB%.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 occurence 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. %BR% 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 immportant 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 [[Customisation|Main/WebHome#TemPlates]], below. ## Customisation Customisation of the comment plugin requires - familiarity with HTML forms - some familiarity with the [[TWiki templating language|TWiki/TWikiTemplates]]. 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 customisations. This allows for several levels of customisation: 1. To **override all default templates, everywhere**, change `comments.tmpl` to include a different topic (this customisation will be lost next time you upgrade, though). 2. To add **site-wide local template customisations**, 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 capitalised, e.g. Pattern) You can also define a **comment template in a topic**, by passing the topic location with `templatetopic`. 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|Main/CommentPluginExamples#TemplateTopic]]. %X% Templates are picked up by following the [[standard TWiki rules|Main/TWikiTemplates#Finding_Templates]] for locating template files. Note that you can use `%TMPL:INCLUDE` to include other files of templates. %BR% %X% 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. ### Customisation example Provide both a `PROMPT` and an `OUTPUT` definition: %TMPL:DEF{PROMPT:myComment}%%TMPL:P{promptbox}%%TMPL:END% %TMPL:DEF{OUTPUT:myComment}%%TMPL:P{outputoneliner}%%POS:TOP% %TMPL:END% Call your custom comment with: %COMMENT{type="myComment"}% ### 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. Only the input fields of the form need be defined. The plugin automatically generates the `
` and `
` tags, unless you specify `noform="on"`, in which case you have to provide them yourself. **Note** that you must define a "submit" button if you want the form to work! #### Providing attribute values If an attribute is given to the `%COMMENT` tag that is not one of the [[standard attributes|Main/WebHome#StandardAttrs]], 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: