Source: feature/files/file-handlers.js

/**
 * Provides a way to register file-handlers to handle rendering the source of a file or the diff of file changed.
 * For example, a {@linkCode FileHandler} can be registered to handle .stl files and render them as 3D files.
 * JS files registering file-handlers should use the resource context 'bitbucket.internal.feature.files.fileHandlers'.
 *
 * **This module is available synchronously.**
 *
 * **Web Resource:** com.atlassian.bitbucket.server.bitbucket-web-api:file-handlers
 *
 * @namespace bitbucket/feature/files/file-handlers
 *
 * @example
 * function MyView(options) {
 *     var $element = $('<div/>');
 *     $container.append($element);
 *
 *     return {
 *         destroy: function() {
 *             $element.remove();
 *         },
 *         extraClasses: 'my-class something-else'
 *     };
 * }
 *
 * var myFileHandler = {
 *     weight: 400,
 *     handle: function(options) {
 *         if (options.fileChange.path.extension === 'stl') {
 *             return new MyView(options);
 *         } else if (options.fileChange.path.extension === 'stl2') {
 *             // Returning a rejected promise with a message will display errors appropriately
 *             return $.Deferred().reject('File extension not supported');
 *         }
 *         // Return null/undefined or an empty promise to pass silently
 *     }
 * };
 *
 * // Register your handler immediately to ensure it is in place when needed.
 * // Note that we use the synchronous syntax to require the module, which ensures there is no delay before
 * // register() is called.
 * require('feature/file-content/file-handlers').register(myFileHandler);
 */
define('bitbucket/feature/files/file-handlers', [
    'bitbucket/internal/util/handler-registry',
    'bitbucket/internal/util/object',
],
/**
 * @exports bitbucket/feature/files/file-handlers
 */
function(
    HandlerRegistry,
    object
) {

    'use strict';

    var fileHandlers = new HandlerRegistry();

    /**
     * @typedef {Object}    FileHandlingContext
     * @memberOf bitbucket/feature/files/file-handlers
     *
     * @property {string}           contentMode - The mode of content. This is either 'source' or 'diff'.
     * @property {jQuery}           $toolbar - A jQuery object pointing to the toolbar contents - any toolbar web panels can be found as descendants. (Since 3.5)
     * @property {jQuery}           $container  - A jQuery object in which you should append your rendered file content.
     * @property {JSON.FileChangeJSON}   fileChange - Describes the changed file.
     * @property {string}           commentMode - The comment rendering mode. "none", "read", "reply-only", or "create-new"
     * @property {boolean}          isExcerpt - Indicates whether this is only an excerpt and not a full file/diff.
     * @property {*}                anchor - An anchor of any type which can be used by the appropriate handler to deep link into the content
     * @property {string}           [scrollStyle] - The style of scrolling to be used, "fixed" or "inline".
     * @property {Function}         [diffUrlBuilder] - An optional function that accepts a {JSON.FileChangeJSON} and will return
     *                                                 a {bitbucket/util/navbuilder.Builder} to the built-in Stash REST
     *                                                 endpoint to obtain the diff information.
     * @property {Array<JSON.CommentJSON>}    [lineComments] - An array of comments anchored to the lines of the file. The structure
     *                                      matches the structure for comments retrieved via the REST API. This is only provided
     *                                      for handling diffs as activity items for a pull request. For other usages, line comments
     *                                      will be retrieved from the server when retrieving diffs.
     * @property {Function}         [commentUrlBuilder] – An optional function that returns a {bitbucket/util/navbuilder.Builder} to the built-in Stash REST
     *                                                 endpoint to send the comment information.
     * @property {DiffViewType}         diffViewType - the type of diff being displayed - an effective merge diff, or a common ancestor diff
     */

    /**
     * Callback to handle file.
     *
     * @callback FileHandleCallback
     * @memberOf bitbucket/feature/files/file-handlers
     *
     * @param {bitbucket/feature/files/file-handlers.FileHandlingContext}   context - A map of properties describing the content
     *                                                              to be rendered and the context in which it is to be rendered.
     * @return {Promise}        A promise object that resolves with {@linkcode FileHandlerResult} if this handler will handle the request, or rejects otherwise.
     */

    /**
     * An object that can either render file sources, file diffs, or both for a particular subset of files.
     *
     * @typedef {Object}    FileHandler
     * @memberOf bitbucket/feature/files/file-handlers
     *
     * @property {number}               [weight=1000] - The weight of handler determining the order it is tried.
     *                                                  The default weight of the source/diff view is 1000.
     * @property {bitbucket/feature/files/file-handlers.FileHandleCallback}   handle        - A function called to handle file content rendering.
     */

    /**
     * @typedef {Object}    FileHandlerResult
     * @memberOf bitbucket/feature/files/file-handlers
     *
     * @property {Function} [destroy]        - A function that will be called before the current view is destroyed, which may happen on state change.
     *                                       This is a chance to destroy/cleanup any event listeners and remove DOM elements.
     * @property {string}   [extraClasses] - Additional style class applied to parent file-content. Can be used to apply background color.
     * @property {string}   [handlerID]    - A unique string identifying your handler (or a "sub-" handler if your handler has a few different ways
     *                                       to display data). This is passed to toolbar web-fragments so they can enable or disable themselves based
     *                                       on which handler is being displayed.
     *
     *                                       The built-in handler IDs are listed in {@link bitbucket/feature-files/file-handlers#builtInHandlers}. Your handler
     *                                       should NOT use these IDs, but should instead specify a unique ID string of its own.
     *
     */

    /**
     * Register a file handler. Call this method as soon as possible to ensure your handler is considered when a file content is loaded.
     *
     * @memberof bitbucket/feature/files/file-handlers
     * @param {FileHandler} fileHandler - your file handler to register
     */
    function register(fileHandler) {}

    /**
     * An enum of built-in handlers that may be used to handle the display of file content. It is not an exhaustive list.
     * Any plugin can handle any file it wishes and may or may not provide an ID.
     *
     * @enum {string}
     * @readonly
     * @memberof bitbucket/feature/files/file-handlers
     * @param {FileHandler} fileHandler
     */
    fileHandlers.builtInHandlers = {
        /**
         * Generic error handler
         */
        ERROR: 'error',
        /**
         * Directory handler
         */
        DIRECTORY: 'directory',
        /**
         * Textual source handler
         */
        SOURCE_TEXT: 'source-text',
        /**
         * Empty source handler
         */
        SOURCE_EMPTY: 'source-empty',
        /**
         * Image source handler
         */
        SOURCE_IMAGE: 'source-image',
        /**
         * Non-image binary source handler
         */
        SOURCE_BINARY: 'source-binary',
        /**
         * Textual diff handler with side-by-side display
         */
        DIFF_TEXT_SIDE_BY_SIDE: 'diff-text-side-by-side',
        /**
         * Textual diff handler with unified display
         */
        DIFF_TEXT_UNIFIED: 'diff-text-unified',
        /**
         * Empty diff handler
         */
        DIFF_EMPTY: 'diff-empty',
        /**
         * Too-large diff handler
         */
        DIFF_TOO_LARGE: 'diff-too-large',
        /**
         * Image diff handler
         */
        DIFF_IMAGE: 'diff-image',
        /**
         * Non-image binary diff handler
         */
        DIFF_BINARY: 'diff-binary',
    };

    object.freeze(fileHandlers.builtInHandlers);

    return fileHandlers;

});