MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / includes / linkeddata / PageDataRequestHandler.php

diff --git a/includes/linkeddata/PageDataRequestHandler.php b/includes/linkeddata/PageDataRequestHandler.php
new file mode 100644 (file)
index 0000000..43cb44c
--- /dev/null
+++ b/includes/linkeddata/PageDataRequestHandler.php
@@ -0,0 +1,172 @@
+<?php
+
+use Wikimedia\Http\HttpAcceptParser;
+use Wikimedia\Http\HttpAcceptNegotiator;
+
+/**
+ * Request handler implementing a data interface for mediawiki pages.
+ *
+ * @license GPL-2.0+
+ * @author Daniel Kinzler
+ * @author Amir Sarabadanai
+ */
+
+class PageDataRequestHandler {
+
+       /**
+        * Checks whether the request is complete, i.e. whether it contains all information needed
+        * to reply with page data.
+        *
+        * This does not check whether the request is valid and will actually produce a successful
+        * response.
+        *
+        * @param string|null $subPage
+        * @param WebRequest $request
+        *
+        * @return bool
+        * @throws HttpError
+        */
+       public function canHandleRequest( $subPage, WebRequest $request ) {
+               if ( $subPage === '' || $subPage === null ) {
+                       if ( $request->getText( 'target', '' ) === '' ) {
+                               return false;
+                       } else {
+                               return true;
+                       }
+               }
+
+               $parts = explode( '/', $subPage, 2 );
+               if ( $parts !== 2 ) {
+                       $slot = $parts[0];
+                       if ( $slot === 'main' || $slot === '' ) {
+                               return true;
+                       }
+               }
+
+               return false;
+       }
+
+       /**
+        * Main method for handling requests.
+        *
+        * @param string $subPage
+        * @param WebRequest $request The request parameters. Known parameters are:
+        *        - title: the page title
+        *        - format: the format
+        *        - oldid|revision: the revision ID
+        * @param OutputPage $output
+        *
+        * @note: Instead of an output page, a WebResponse could be sufficient, but
+        *        redirect logic is currently implemented in OutputPage.
+        *
+        * @throws HttpError
+        */
+       public function handleRequest( $subPage, WebRequest $request, OutputPage $output ) {
+               // No matter what: The response is always public
+               $output->getRequest()->response()->header( 'Access-Control-Allow-Origin: *' );
+
+               if ( !$this->canHandleRequest( $subPage, $request ) ) {
+                       throw new HttpError( 400, wfMessage( 'pagedata-bad-title', $subPage ) );
+               }
+
+               $revision = 0;
+
+               $parts = explode( '/', $subPage, 2 );
+               if ( $subPage !== '' ) {
+                       $title = $parts[1];
+               } else {
+                       $title = $request->getText( 'target', '' );
+               }
+
+               $revision = $request->getInt( 'oldid', $revision );
+               $revision = $request->getInt( 'revision', $revision );
+
+               if ( $title === null || $title === '' ) {
+                       //TODO: different error message?
+                       throw new HttpError( 400, wfMessage( 'pagedata-bad-title', $title ) );
+               }
+
+               try {
+                       $title = Title::newFromTextThrow( $title );
+               } catch ( MalformedTitleException $ex ) {
+                       throw new HttpError( 400, wfMessage( 'pagedata-bad-title', $title ) );
+               }
+
+               $this->httpContentNegotiation( $request, $output, $title, $revision );
+       }
+
+       /**
+        * Applies HTTP content negotiation.
+        * If the negotiation is successful, this method will set the appropriate redirect
+        * in the OutputPage object and return. Otherwise, an HttpError is thrown.
+        *
+        * @param WebRequest $request
+        * @param OutputPage $output
+        * @param Title $title
+        * @param int $revision The desired revision
+        *
+        * @throws HttpError
+        */
+       public function httpContentNegotiation(
+               WebRequest $request,
+               OutputPage $output,
+               Title $title,
+               $revision = 0
+       ) {
+               $contentHandler = ContentHandler::getForTitle( $title );
+               $mimeTypes = $contentHandler->getSupportedFormats();
+
+               $headers = $request->getAllHeaders();
+               if ( isset( $headers['ACCEPT'] ) ) {
+                       $parser = new HttpAcceptParser();
+                       $accept = $parser->parseWeights( $headers['ACCEPT'] );
+               } else {
+                       // anything goes
+                       $accept = [
+                               '*' => 0.1 // just to make extra sure
+                       ];
+                       // prefer the default
+                       $accept[$mimeTypes[0]] = 1;
+               }
+
+               $negotiator = new HttpAcceptNegotiator( $mimeTypes );
+               $format = $negotiator->getBestSupportedKey( $accept, null );
+
+               if ( $format === null ) {
+                       $format = isset( $accept['text/html'] ) ? 'text/html' : null;
+               }
+
+               if ( $format === null ) {
+                       $msg = wfMessage( 'pagedata-not-acceptable', implode( ', ', $mimeTypes ) );
+                       throw new HttpError( 406, $msg );
+               }
+
+               $url = $this->getDocUrl( $title, $format, $revision );
+               $output->redirect( $url, 303 );
+       }
+
+       /**
+        * Returns a url representing the given title.
+        *
+        * @param Title $title
+        * @param string|null $format The (normalized) format name, or ''
+        * @param int $revision
+        * @return string
+        */
+       private function getDocUrl( Title $title, $format = '', $revision = 0 ) {
+               $params = [];
+
+               if ( $revision > 0 ) {
+                       $params['oldid'] = $revision;
+               }
+
+               if ( $format === 'text/html' ) {
+                       return $title->getFullURL( $params );
+               }
+
+               $params[ 'action' ] = 'raw';
+
+               return $title->getFullURL( $params );
+       }
+
+}