pyblosxom ajax comments

<img class="right" src="ajax.jpg" />

_This patch was applied to the Pyblosxom contributed plugins pack in
[revision 973](http://pyblosxom.svn.sourceforge.net/viewvc/pyblosxom?view=rev&revision=973).
It's included in
[version 1.3.3](http://sourceforge.net/project/showfiles.php?group_id=67445&package_id=145140&release_id=489295)
of the contrib pack._

For the impatient:  
&nbsp; [Download contrib pack 1.3.3](http://sourceforge.net/project/showfiles.php?group_id=67445&package_id=145140&release_id=489295) (includes AJAX support)  
&nbsp; [PyBlosxom home page](http://pyblosxom.sf.net/)  
&nbsp; [PyBlosxom plugin registry](http://pyblosxom.sf.net/blog/registry?sortby=path)

[PyBlosxom](http://pyblosxom.sf.net/), the server software that runs this site,
uses a [plugin](http://pyblosxom.sourceforge.net/blog/registry/input/comments)
to handle commenting.
This patch adds [AJAX](http://en.wikipedia.org/wiki/Ajax_\(programming\))
support to that plugin. [Try it!](#comment-anchor)

Specifically, comment previewing and posting can optionally use AJAX, as
opposed to full HTTP POST requests. This avoids a full-size roundtrip and
re-render, so commenting feels faster and more lightweight.

To enable AJAX comments, set the `comment_ajax` config parameter in
`config.py` to True.

AJAX commenting degrades gracefully in older browsers. If JavaScript is
disabled or not supported in the user's browser, or if it doesn't support
`XmlHttpRequest`, comment posting and preview will use normal HTTP POST.
Feel free to [check out the JavaScript](/comments.js).

Also, since the browser window never sends a full POST request, refreshing the
page after a preview or comment submission won't re-post the comment, or pop up
an annoying "are you sure?" dialog box.

AJAX comment support requires a few elements in the comment-form flavour
template. Specifically, the comment-anchor tag must be the first thing in the
template:

    <a name="comment-anchor" id="comment-anchor"></a>

Also, the buttons in the comment form should include these onsubmit and
onclick attributes:

    <form name="comments_form" ... onsubmit="return false;">
      <input value="Preview" name="preview" type="submit"
             onclick="send_comment('preview');" />
      <input value="Submit" name="submit" type="submit"
             onclick="send_comment('post');" />

Finally, this script tag must be included somewhere after the `</form>` tag:

    <script type="text/javascript" src="/comments.js"></script>

All of these tags are included in the default comment-form template that comes
with this plugin.

AJAX comment support is copyright 2006 [Ryan Barrett](about), and is
distributed under the [GPL](http://www.gnu.org/licenses/gpl.html). Thanks to
[Todd Warner](http://www.dma.org/cgi-bin/cgiwrap/tw/toddblog) and
[Blake Winton](http://bwinton.latte.ca/)
for beta testing and improvements.

See also:

  * [migrating to pyblosxom](2006-08-23_virtual_housewarming)
  * [filekicker](filekicker)
  * [photogallery](photogallery)
  * [hardcodedates](hardcodedates)
  * [pyblosxom rdf flavour](pyblosxom_rdf_flavour)