On Mon, Jun 28, 2010 at 8:19 PM, Samuel Lampa <[email protected]>wrote:
> Is it possible (and if so, how to) totally replace the output from a
> Special page (including the sending headers etc)?
>
> That is, can I use a SpecialPage as a SPARQL Endpoint and have it output
> pure RDF/XML (or similar) if a SPARQL query is sent to it via POST,
> while if not, it should just display the SpecialPage including a form
> for submitting a SPARQL query.
>
It sure is! In your execute() method, you'll want to call $wgOut->disable().
This'll turn off the regular page display output at the end of request
processing, and give you a chance to take over and do whatever you like, eg
sending appropriate HTTP headers and output directly.
The traditional example I always like to use is Special:Export in the core
code. If you bump down a bit past the initialization code and input
validation, you'll see this code that's called just before we're actually
doing the XML output:
if ( $this->doExport ) {
$wgOut->disable();
// Cancel output buffering and gzipping if set
// This should provide safer streaming for pages with history
wfResetOutputBuffers();
$wgRequest->response()->header( "Content-type: application/xml;
charset=utf-8" );
You should always be sure to set the content-type correctly; and if
outputting XML or HTML, be sure to include a charset header.
The wfResetOutputBuffers() bit isn't required in most cases, but if you're
outputting a *lot* of data it can help to let you stream output directly to
the downloader. (By default, buffering is used to apply gzip encoding and
send a Content-Size header. This is usually good, but means that all your
output has to be built and stored in memory before it actually gets sent to
the client... potentially a problem if you're streaming out fifty thousand
revisions of [[Hurricane Katrina]]!)
When you're doing your raw output, you can go ahead and do 'print' or 'echo'
directly if you like -- you're now in control. ;)
As a general note -- always be careful of your output to make sure you're
applying proper escaping when generating HTML or XML; raw output can be a
security risk if input isn't sanitized properly.
-- brion vibber (brion @ pobox.com)
_______________________________________________
Wikitech-l mailing list
[email protected]
https://lists.wikimedia.org/mailman/listinfo/wikitech-l
