Difference between revisions of "MediaWiki:Common.js"

Revision as of 17:00, 6 June 2018

/**
 * jQuery makeCollapsible
 * Note: To avoid performance issues such as reflows, several styles are
 * shipped in mediawiki.makeCollapsible.styles to reserve space for the toggle control. Please
 * familiarise yourself with that CSS before making any changes to this code.
 *
 * Dual licensed:
 * - CC BY 3.0 <http://creativecommons.org/licenses/by/3.0>
 * - GPL2 <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
 *
 * @class jQuery.plugin.makeCollapsible
 */
( function ( $, mw ) {
  /**
   * Handler for a click on a collapsible toggler.
   *
   * @private
   * @param {jQuery} $collapsible
   * @param {string} action The action this function will take ('expand' or 'collapse').
   * @param {jQuery|null} [$defaultToggle]
   * @param {Object|undefined} [options]
   */
  function toggleElement( $collapsible, action, $defaultToggle, options ) {
    var $collapsibleContent, $containers, hookCallback;
    options = options || {};

    // Validate parameters

    // $collapsible must be an instance of jQuery
    if ( !$collapsible.jquery ) {
      return;
    }
    if ( action !== 'expand' && action !== 'collapse' ) {
      // action must be string with 'expand' or 'collapse'
      return;
    }
    if ( $defaultToggle === undefined ) {
      $defaultToggle = null;
    }

    // Trigger a custom event to allow callers to hook to the collapsing/expanding,
    // allowing the module to be testable, and making it possible to
    // e.g. implement persistence via cookies
    $collapsible.trigger( action === 'expand' ? 'beforeExpand.mw-collapsible' : 'beforeCollapse.mw-collapsible' );
    hookCallback = function () {
      $collapsible.trigger( action === 'expand' ? 'afterExpand.mw-collapsible' : 'afterCollapse.mw-collapsible' );
    };

    // Handle different kinds of elements
    if ( !options.plainMode && $collapsible.is( 'table' ) ) {
      // Tables
      // If there is a caption, hide all rows; otherwise, only hide body rows
      if ( $collapsible.find( '> caption' ).length ) {
        $containers = $collapsible.find( '> * > tr' );
      } else {
        $containers = $collapsible.find( '> tbody > tr' );
      }
      if ( $defaultToggle ) {
        // Exclude table row containing togglelink
        $containers = $containers.not( $defaultToggle.closest( 'tr' ) );
      }

    } else if ( !options.plainMode && ( $collapsible.is( 'ul' ) || $collapsible.is( 'ol' ) ) ) {
      // Lists
      $containers = $collapsible.find( '> li' );
      if ( $defaultToggle ) {
        // Exclude list-item containing togglelink
        $containers = $containers.not( $defaultToggle.parent() );
      }
    } else {
      // Everything else: <div>, <p> etc.
      $collapsibleContent = $collapsible.find( '> .mw-collapsible-content' );

      // If a collapsible-content is defined, act on it
      if ( !options.plainMode && $collapsibleContent.length ) {
        $containers = $collapsibleContent;

      // Otherwise assume this is a customcollapse with a remote toggle
      // .. and there is no collapsible-content because the entire element should be toggled
      } else {
        $containers = $collapsible;
      }
    }

    $containers.toggle( action === 'expand' );
    hookCallback();
  }

  /**
   * Handle clicking/keypressing on the collapsible element toggle and other
   * situations where a collapsible element is toggled (e.g. the initial
   * toggle for collapsed ones).
   *
   * @private
   * @param {jQuery} $toggle the clickable toggle itself
   * @param {jQuery} $collapsible the collapsible element
   * @param {jQuery.Event|null} e either the event or null if unavailable
   * @param {Object|undefined} options
   */
  function togglingHandler( $toggle, $collapsible, e, options ) {
    var wasCollapsed, $textContainer, collapseText, expandText;
    options = options || {};

    if ( e ) {
      if (
        e.type === 'click' &&
        e.target.nodeName.toLowerCase() === 'a' &&
        $( e.target ).attr( 'href' )
      ) {
        // Don't fire if a link was clicked (for premade togglers)
        return;
      } else if ( e.type === 'keypress' && e.which !== 13 && e.which !== 32 ) {
        // Only handle keypresses on the "Enter" or "Space" keys
        return;
      } else {
        e.preventDefault();
        e.stopPropagation();
      }
    }

    // This allows the element to be hidden on initial toggle without fiddling with the class
    if ( options.wasCollapsed !== undefined ) {
      wasCollapsed = options.wasCollapsed;
    } else {
      wasCollapsed = $collapsible.hasClass( 'mw-collapsed' );
    }

    // Toggle the state of the collapsible element (that is, expand or collapse)
    $collapsible.toggleClass( 'mw-collapsed', !wasCollapsed );

    // Toggle the mw-collapsible-toggle classes, if requested (for default and premade togglers by default)
    if ( options.toggleClasses ) {
      $toggle
        .toggleClass( 'mw-collapsible-toggle-collapsed', !wasCollapsed )
        .toggleClass( 'mw-collapsible-toggle-expanded', wasCollapsed );
    }

    // Toggle the text ("Show"/"Hide") within elements tagged with mw-collapsible-text
    if ( options.toggleText ) {
      collapseText = options.toggleText.collapseText;
      expandText = options.toggleText.expandText;

      $textContainer = $toggle.find( '.mw-collapsible-text' );
      if ( $textContainer.length ) {
        $textContainer.text( wasCollapsed ? collapseText : expandText );
      }
    }

    // And finally toggle the element state itself
    toggleElement( $collapsible, wasCollapsed ? 'expand' : 'collapse', $toggle, options );
  }

  /**
   * Enable collapsible-functionality on all elements in the collection.
   *
   * - Will prevent binding twice to the same element.
   * - Initial state is expanded by default, this can be overridden by adding class
   *   "mw-collapsed" to the "mw-collapsible" element.
   * - Elements made collapsible have jQuery data "mw-made-collapsible" set to true.
   * - The inner content is wrapped in a "div.mw-collapsible-content" (except for tables and lists).
   *
   * @param {Object} [options]
   * @param {string} [options.collapseText] Text used for the toggler, when clicking it would
   *   collapse the element. Default: the 'data-collapsetext' attribute of the
   *   collapsible element or the content of 'collapsible-collapse' message.
   * @param {string} [options.expandText] Text used for the toggler, when clicking it would
   *   expand the element. Default: the 'data-expandtext' attribute of the
   *   collapsible element or the content of 'collapsible-expand' message.
   * @param {boolean} [options.collapsed] Whether to collapse immediately. By default
   *   collapse only if the element has the 'mw-collapsed' class.
   * @param {jQuery} [options.$customTogglers] Elements to be used as togglers
   *   for this collapsible element. By default, if the collapsible element
   *   has an id attribute like 'mw-customcollapsible-XXX', elements with a
   *   *class* of 'mw-customtoggle-XXX' are made togglers for it.
   * @param {boolean} [options.plainMode=false] Whether to use a "plain mode" when making the
   *   element collapsible - that is, hide entire tables and lists (instead
   *   of hiding only all rows but first of tables, and hiding each list
   *   item separately for lists) and don't wrap other elements in
   *   div.mw-collapsible-content. May only be used with custom togglers.
   * @return {jQuery}
   * @chainable
   */
  $.fn.makeCollapsible = function ( options ) {
    options = options || {};

    this.each( function () {
      var $collapsible, collapseText, expandText, $caption, $toggle, actionHandler,
        buildDefaultToggleLink, $firstItem, collapsibleId, $customTogglers, firstval;

      // Ensure class "mw-collapsible" is present in case .makeCollapsible()
      // is called on element(s) that don't have it yet.
      $collapsible = $( this ).addClass( 'mw-collapsible' );

      // Return if it has been enabled already.
      if ( $collapsible.data( 'mw-made-collapsible' ) ) {
        return;
      } else {
        // Let CSS know that it no longer needs to worry about flash of unstyled content.
        // This will allow mediawiki.makeCollapsible.styles to disable temporary pseudo elements, that
        // are needed to avoid a flash of unstyled content.
        $collapsible.addClass( 'mw-made-collapsible' )
          .data( 'mw-made-collapsible', true );
      }

      // Use custom text or default?
      collapseText = options.collapseText || $collapsible.attr( 'data-collapsetext' ) || mw.msg( 'collapsible-collapse' );
      expandText = options.expandText || $collapsible.attr( 'data-expandtext' ) || mw.msg( 'collapsible-expand' );

      // Default click/keypress handler and toggle link to use when none is present
      actionHandler = function ( e, opts ) {
        var defaultOpts = {
          toggleClasses: true,
          toggleText: { collapseText: collapseText, expandText: expandText }
        };
        opts = $.extend( defaultOpts, options, opts );
        togglingHandler( $( this ), $collapsible, e, opts );
      };

      // Default toggle link. Only build it when needed to avoid jQuery memory leaks (event data).
      buildDefaultToggleLink = function () {
        return $( '<a class="mw-collapsible-text"></a>' )
          .text( collapseText )
          .wrap( '<span class="mw-collapsible-toggle mw-collapsible-toggle-default"></span>' )
          .parent()
          .attr( {
            role: 'button',
            tabindex: 0
          } );
      };

      // Check if this element has a custom position for the toggle link
      // (ie. outside the container or deeper inside the tree)
      if ( options.$customTogglers ) {
        $customTogglers = $( options.$customTogglers );
      } else {
        collapsibleId = $collapsible.attr( 'id' ) || '';
        if ( collapsibleId.indexOf( 'mw-customcollapsible-' ) === 0 ) {
          $customTogglers = $( '.' + collapsibleId.replace( 'mw-customcollapsible', 'mw-customtoggle' ) )
            .addClass( 'mw-customtoggle' );
        }
      }

      // Add event handlers to custom togglers or create our own ones
      if ( $customTogglers && $customTogglers.length ) {
        actionHandler = function ( e, opts ) {
          var defaultOpts = {};
          opts = $.extend( defaultOpts, options, opts );
          togglingHandler( $( this ), $collapsible, e, opts );
        };

        $toggle = $customTogglers;

      } else {
        // If this is not a custom case, do the default: wrap the
        // contents and add the toggle link. Different elements are
        // treated differently.

        if ( $collapsible.is( 'table' ) ) {

          // If the table has a caption, collapse to the caption
          // as opposed to the first row
          $caption = $collapsible.find( '> caption' );
          if ( $caption.length ) {
            $toggle = $caption.find( '> .mw-collapsible-toggle' );

            // If there is no toggle link, add it to the end of the caption
            if ( !$toggle.length ) {
              $toggle = buildDefaultToggleLink().appendTo( $caption );
            }
          } else {
            // The toggle-link will be in one of the cells (td or th) of the first row
            $firstItem = $collapsible.find( 'tr:first th, tr:first td' );
            $toggle = $firstItem.find( '> .mw-collapsible-toggle' );

            // If theres no toggle link, add it to the last cell
            if ( !$toggle.length ) {
              $toggle = buildDefaultToggleLink().prependTo( $firstItem.eq( -1 ) );
            }
          }

        } else if ( $collapsible.parent().is( 'li' ) &&
          $collapsible.parent().children( '.mw-collapsible' ).length === 1 &&
          $collapsible.find( '> .mw-collapsible-toggle' ).length === 0
        ) {
          // special case of one collapsible in <li> tag
          $toggle = buildDefaultToggleLink();
          $collapsible.before( $toggle );
        } else if ( $collapsible.is( 'ul' ) || $collapsible.is( 'ol' ) ) {
          // The toggle-link will be in the first list-item
          $firstItem = $collapsible.find( 'li:first' );
          $toggle = $firstItem.find( '> .mw-collapsible-toggle' );

          // If theres no toggle link, add it
          if ( !$toggle.length ) {
            // Make sure the numeral order doesn't get messed up, force the first (soon to be second) item
            // to be "1". Except if the value-attribute is already used.
            // If no value was set WebKit returns "", Mozilla returns '-1', others return 0, null or undefined.
            firstval = $firstItem.prop( 'value' );
            if ( firstval === undefined || !firstval || firstval === '-1' || firstval === -1 ) {
              $firstItem.prop( 'value', '1' );
            }
            $toggle = buildDefaultToggleLink();
            $toggle.wrap( '<li class="mw-collapsible-toggle-li"></li>' ).parent().prependTo( $collapsible );
          }

        } else { // <div>, <p> etc.

          // The toggle-link will be the first child of the element
          $toggle = $collapsible.find( '> .mw-collapsible-toggle' );

          // If a direct child .content-wrapper does not exists, create it
          if ( !$collapsible.find( '> .mw-collapsible-content' ).length ) {
            $collapsible.wrapInner( '<div class="mw-collapsible-content"></div>' );
          }

          // If theres no toggle link, add it
          if ( !$toggle.length ) {
            $toggle = buildDefaultToggleLink().prependTo( $collapsible );
          }
        }
      }

      // Attach event handlers to togglelink
      $toggle.on( 'click.mw-collapsible keypress.mw-collapsible', actionHandler )
        .prop( 'tabIndex', 0 );

      $( this ).data( 'mw-collapsible', {
        collapse: function () {
          actionHandler.call( $toggle.get( 0 ), null, { wasCollapsed: false } );
        },
        expand: function () {
          actionHandler.call( $toggle.get( 0 ), null, { wasCollapsed: true } );
        },
        toggle: function () {
          actionHandler.call( $toggle.get( 0 ), null, null );
        }
      } );

      // Initial state
      if ( options.collapsed || $collapsible.hasClass( 'mw-collapsed' ) ) {
        // One toggler can hook to multiple elements, and one element can have
        // multiple togglers. This is the sanest way to handle that.
        actionHandler.call( $toggle.get( 0 ), null, { wasCollapsed: false } );
      }

    } );

    /**
     * Fired after collapsible content has been initialized
     *
     * This gives an option to modify the collapsible behavior.
     *
     * @event wikipage_collapsibleContent
     * @member mw.hook
     * @param {jQuery} $content All the elements that have been made collapsible
     */
    mw.hook( 'wikipage.collapsibleContent' ).fire( this );

    return this;
  };

  /**
   * @class jQuery
   * @mixins jQuery.plugin.makeCollapsible
   */

}( jQuery, mediaWiki ) );