2023/06/24

Saturday, June 24, 2023 (#175)

Friday Saturday Sunday Notes SpecialPageFactory.php line 1449 (was 1318) calls $this->getPage( $name ); SpecialPageFactory.php line 1411 (was 1283) calls $this->objectFactory->createObject($rec,['allowClassName' => true,'allowCallable' => true]); This seems to be where the problem comes in: $rec is supposed to be an array or a string that matches certain criteria. $rec = $specialPageList[$realName]; [ $realName ] = $this->resolveAlias( $name ); // extracts $realName from the first item returned (the "real name" is always first, I guess... seems a bit sloppy) ObjectFactory.php line 152 calls static::getObjectFromSpec( $spec, $options ); ObjectFactory.php line 177 calls static::validateSpec( $spec, $options ); ObjectFactory.php line 302 is in validateSpec( $spec, array $options ), throws exception the problem flows like this: in this->getPage( $name ); we have if ( is_array( $rec ) || is_string( $rec ) || is_callable( $rec ) ) { $page = $this->objectFactory->createObject( $rec, [ 'allowClassName' => true,'allowCallable' => true ]); } ...which implies that it should be perfectly okay to call createObject() with a string, but then we have createObject( $spec, array $options = [] ) calling static::getObjectFromSpec( $spec, $options ); which calls static::validateSpec( $spec, $options ); which then goes: if ( is_string( $spec ) && class_exists( $spec ) ) { if ( empty( $options['allowClassName'] ) ) { throw new InvalidArgumentException('Passing a raw class name is not allowed here. Use [ \'class\' => $classname ] instead.'); } return [ 'class' => $spec ]; } if ( !is_array( $spec ) ) { throw new InvalidArgumentException( 'Provided specification is not an array.' ); } ...so I think what I'm getting from that is that it's only okay to call $this->objectFactory->createObject( $rec, /*...*/ ) if $rec is not a class name. So then we have the questions: Q1: From where is the string-value of $rec being retrieved? The list comes from $this->getPageList() ...and how that list is generated is... Complicated. ...but there's a wide variety of examples, when CORE_LIST is defined near the top of the class, of what the array entries are supposed to look like. Q1a: So, somehow our SpecialPage class gets added to the list as just a string. Where does that happen? Presumably in SpecialPage's constructor... Nope, not there; that just initializes the SpecialPage object's members. Presumably the class is registered by whatever reads the extension.json file. Q1a1: How are extension pages loaded? Q2: What is it supposed to be, if it's not a class name? I don't know the answer to the above questions, but I did solve the problem: as implied on Manual:Special_pages, the filename must match the class name -- so it can't be just Special.php, it has to be SpecialClassInspector.php. (Maybe there's some configuration detail you can put in extension.json to override this, but I don't currently know what that is if it exists.)