Allow to customise addHelpLink() target via system message

Method similar to SpecialPage::outputHeader() to avoid registering
tons of system messages and to have -summary and -helppage tidily
listed together in Special:AllMessages by default.

Bug: T45591
Change-Id: Ic849dde00be7379c1909a8486cf20f48c5aea5cf

RELEASE-NOTES-1.25

@@ -382,6 +382,10 @@ changes to languages because of Bugzilla reports.
   bugs and ensure better reading experience for different variants.
 
 === Other changes in 1.25 ===
+* (T45591) Links to MediaWiki.org translatable help were added to indicators,
+  mostly in special pages. Local custom target titles can be placed in the
+  relevant '(namespace-X|action name|special page name)-helppage' system
+  message. Extensions can use the addHelpLink() function to do the same.
 * The skin autodiscovery mechanism, deprecated in MediaWiki 1.23, has been
   removed. See https://www.mediawiki.org/wiki/Manual:Skin_autodiscovery for
   migration guide for creators and users of custom skins that relied on it.

includes/OutputPage.php

@@ -1401,8 +1401,10 @@ class OutputPage extends ContextSource {
 
 	/**
 	 * Adds help link with an icon via page indicators.
-	 * @param string $to
-	 * @param bool $overrideBaseUrl
+	 * Link target can be overridden by a local message containing a wikilink:
+	 * the message key is: lowercase action or special page name + '-helppage'.
+	 * @param string $to Target MediaWiki.org page title or encoded URL.
+	 * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
 	 * @since 1.25
 	 */
 	public function addHelpLink( $to, $overrideBaseUrl = false ) {
@@ -1415,6 +1417,7 @@ class OutputPage extends ContextSource {
 			$toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
 			$helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
 		}
+
 		$link = Html::rawElement(
 			'a',
 			array(

includes/actions/Action.php

@@ -376,6 +376,25 @@ abstract class Action {
 		return $this->msg( strtolower( $this->getName() ) )->escaped();
 	}
 
+	/**
+	 * Adds help link with an icon via page indicators.
+	 * Link target can be overridden by a local message containing a wikilink:
+	 * the message key is: lowercase action name + '-helppage'.
+	 * @param string $to Target MediaWiki.org page title or encoded URL.
+	 * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
+	 * @since 1.25
+	 */
+	public function addHelpLink( $to, $overrideBaseUrl = false ) {
+		$msg = wfMessage( $wgContLang->lc( $this->getActionName() ) . '-helppage' );
+
+		if ( !$msg->isDisabled() ) {
+			$helpUrl = Skin::makeUrl( $msg->plain() );
+			$this->getOutput()->addHelpLink( $helpUrl, true );
+		} else {
+			$this->getOutput()->addHelpLink( $to, $overrideBaseUrl );
+		}
+	}
+
 	/**
 	 * The main action entry point.  Do all output for display and send it to the context
 	 * output.  Do not use globals $wgOut, $wgRequest, etc, in implementations; use

includes/actions/DeleteAction.php

@@ -48,7 +48,7 @@ class DeleteAction extends FormlessAction {
 				'mediawiki.ui.checkbox',
 			) );
 		}
-		$out->addHelpLink( 'Help:Sysop deleting and undeleting' );
+		$this->addHelpLink( 'Help:Sysop deleting and undeleting' );
 		$this->page->delete();
 	}
 }

includes/page/Article.php

@@ -1505,6 +1505,27 @@ class Article implements Page {
 			'</div>';
 	}
 
+	/**
+	 * Adds help link with an icon via page indicators.
+	 * Link target can be overridden by a local message containing a wikilink:
+	 * the message key is: 'namespace-' + namespace number + '-helppage'.
+	 * @param string $to Target MediaWiki.org page title or encoded URL.
+	 * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
+	 * @since 1.25
+	 */
+	public function addHelpLink( $to, $overrideBaseUrl = false ) {
+		$msg = wfMessage(
+			'namespace-' . $this->getTitle()->getNamespace() . '-helppage'
+		);
+
+		if ( !$msg->isDisabled() ) {
+			$helpUrl = Skin::makeUrl( $msg->plain() );
+			$this->getOutput()->addHelpLink( $helpUrl, true );
+		} else {
+			$this->getOutput()->addHelpLink( $to, $overrideBaseUrl );
+		}
+	}
+
 	/**
 	 * Handle action=render
 	 */

includes/page/CategoryPage.php

@@ -115,6 +115,6 @@ class CategoryPage extends Article {
 		);
 		$out = $this->getContext()->getOutput();
 		$out->addHTML( $viewer->getHTML() );
-		$out->addHelpLink( 'Help:Categories' );
+		$this->addHelpLink( 'Help:Categories' );
 	}
 }

includes/specialpage/SpecialPage.php

@@ -632,6 +632,26 @@ class SpecialPage {
 		}
 	}
 
+	/**
+	 * Adds help link with an icon via page indicators.
+	 * Link target can be overridden by a local message containing a wikilink:
+	 * the message key is: lowercase special page name + '-helppage'.
+	 * @param string $to Target MediaWiki.org page title or encoded URL.
+	 * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
+	 * @since 1.25
+	 */
+	public function addHelpLink( $to, $overrideBaseUrl = false ) {
+		global $wgContLang;
+		$msg = $this->msg( $wgContLang->lc( $this->getName() ) . '-helppage' );
+
+		if ( !$msg->isDisabled() ) {
+			$helpUrl = Skin::makeUrl( $msg->plain() );
+			$this->getOutput()->addHelpLink( $helpUrl, true );
+		} else {
+			$this->getOutput()->addHelpLink( $to, $overrideBaseUrl );
+		}
+	}
+
 	/**
 	 * Get the group that the special page belongs in on Special:SpecialPage
 	 * Use this method, instead of getGroupName to allow customization

includes/specials/SpecialAllMessages.php

@@ -59,7 +59,7 @@ class SpecialAllMessages extends SpecialPage {
 
 		$this->outputHeader( 'allmessagestext' );
 		$out->addModuleStyles( 'mediawiki.special' );
-		$out->addHelpLink( 'Help:System message' );
+		$this->addHelpLink( 'Help:System message' );
 
 		$this->table = new AllMessagesTablePager(
 			$this,

includes/specials/SpecialBlock.php

@@ -103,7 +103,7 @@ class SpecialBlock extends FormSpecialPage {
 		$msg = $this->alreadyBlocked ? 'ipb-change-block' : 'ipbsubmit';
 		$form->setSubmitTextMsg( $msg );
 
-		$this->getOutput()->addHelpLink( 'Help:Blocking users' );
+		$this->addHelpLink( 'Help:Blocking users' );
 
 		# Don't need to do anything if the form has been posted
 		if ( !$this->getRequest()->wasPosted() && $this->preErrors ) {

includes/specials/SpecialDiff.php

@@ -57,7 +57,7 @@ class SpecialDiff extends RedirectSpecialPage {
 			$this->mAddedRedirectParams['diff'] = $parts[1];
 		} else {
 			// Wrong number of parameters, bail out
-			$this->getOutput()->addHelpLink( 'Help:Diff' );
+			$this->addHelpLink( 'Help:Diff' );
 			throw new ErrorPageError( 'nopagetitle', 'nopagetext' );
 		}
 

includes/specials/SpecialEditTags.php

@@ -206,7 +206,7 @@ class SpecialEditTags extends UnlistedSpecialPage {
 			$this->targetObj->getPrefixedText()
 		) );
 
-		$out->addHelpLink( 'Help:Tags' );
+		$this->addHelpLink( 'Help:Tags' );
 		$out->addHTML( "<ul>" );
 
 		$numRevisions = 0;

includes/specials/SpecialMergeHistory.php

@@ -187,7 +187,7 @@ class SpecialMergeHistory extends SpecialPage {
 				'</form>'
 		);
 
-		$out->addHelpLink( 'Help:Merge history' );
+		$this->addHelpLink( 'Help:Merge history' );
 	}
 
 	private function showHistory() {

includes/specials/SpecialMovepage.php

@@ -140,7 +140,7 @@ class MovePageForm extends UnlistedSpecialPage {
 		$out = $this->getOutput();
 		$out->setPageTitle( $this->msg( 'move-page', $this->oldTitle->getPrefixedText() ) );
 		$out->addModules( 'mediawiki.special.movePage' );
-		$out->addHelpLink( 'Help:Moving a page' );
+		$this->addHelpLink( 'Help:Moving a page' );
 
 		$newTitle = $this->newTitle;
 

includes/specials/SpecialNewimages.php

@@ -31,7 +31,7 @@ class SpecialNewFiles extends IncludableSpecialPage {
 		$this->outputHeader();
 
 		$out = $this->getOutput();
-		$out->addHelpLink( 'Help:New images' );
+		$this->addHelpLink( 'Help:New images' );
 
 		$pager = new NewFilesPager( $this->getContext(), $par );
 

includes/specials/SpecialNewpages.php

@@ -127,7 +127,7 @@ class SpecialNewpages extends IncludableSpecialPage {
 		$this->showNavigation = !$this->including(); // Maybe changed in setup
 		$this->setup( $par );
 
-		$out->addHelpLink( 'Help:New pages' );
+		$this->addHelpLink( 'Help:New pages' );
 
 		if ( !$this->including() ) {
 			// Settings

includes/specials/SpecialPreferences.php

@@ -55,7 +55,7 @@ class SpecialPreferences extends SpecialPage {
 			);
 		}
 
-		$out->addHelpLink( 'Help:Preferences' );
+		$this->addHelpLink( 'Help:Preferences' );
 
 		$htmlForm = Preferences::getFormObject( $this->getUser(), $this->getContext() );
 		$htmlForm->setSubmitCallback( array( 'Preferences', 'tryUISubmit' ) );

includes/specials/SpecialRandomInCategory.php

@@ -68,7 +68,7 @@ class SpecialRandomInCategory extends FormSpecialPage {
 	}
 
 	protected function getFormFields() {
-		$this->getOutput()->addHelpLink( 'Help:RandomInCategory' );
+		$this->addHelpLink( 'Help:RandomInCategory' );
 
 		$form = array(
 			'category' => array(

includes/specials/SpecialRevisiondelete.php

@@ -368,7 +368,7 @@ class SpecialRevisionDelete extends UnlistedSpecialPage {
 		$out->wrapWikiMsg( "<strong>$1</strong>", array( $this->typeLabels['selected'],
 			$this->getLanguage()->formatNum( count( $this->ids ) ), $this->targetObj->getPrefixedText() ) );
 
-		$out->addHelpLink( 'Help:RevisionDelete' );
+		$this->addHelpLink( 'Help:RevisionDelete' );
 		$out->addHTML( "<ul>" );
 
 		$numRevisions = 0;

includes/specials/SpecialSpecialpages.php

@@ -45,7 +45,7 @@ class SpecialSpecialpages extends UnlistedSpecialPage {
 			return;
 		}
 
-		$out->addHelpLink( 'Help:Special pages' );
+		$this->addHelpLink( 'Help:Special pages' );
 		$this->outputPageList( $groups );
 	}
 

includes/specials/SpecialUndelete.php

@@ -791,7 +791,7 @@ class SpecialUndelete extends SpecialPage {
 			return;
 		}
 
-		$out->addHelpLink( 'Help:Undelete' );
+		$this->addHelpLink( 'Help:Undelete' );
 		if ( $this->mAllowed ) {
 			$out->setPageTitle( $this->msg( 'undeletepage' ) );
 		} else {

includes/specials/SpecialUpload.php

@@ -160,7 +160,7 @@ class SpecialUpload extends SpecialPage {
 			throw new ErrorPageError( 'uploaddisabled', 'uploaddisabledtext' );
 		}
 
-		$this->getOutput()->addHelpLink( 'Help:Managing files' );
+		$this->addHelpLink( 'Help:Managing files' );
 
 		# Check permissions
 		$user = $this->getUser();

includes/specials/SpecialUserrights.php

@@ -135,7 +135,7 @@ class UserrightsPage extends SpecialPage {
 
 		$out = $this->getOutput();
 		$out->addModuleStyles( 'mediawiki.special' );
-		$out->addHelpLink( 'Help:Assigning permissions' );
+		$this->addHelpLink( 'Help:Assigning permissions' );
 
 		// show the general form
 		if ( count( $available['add'] ) || count( $available['remove'] ) ) {