openproject/frontend/app/components/api/api-v3/hal/hal-resource.service.ts

//-- copyright
// OpenProject is a project management system.
// Copyright (C) 2012-2015 the OpenProject Foundation (OPF)
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License version 3.
//
// OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
// Copyright (C) 2006-2013 Jean-Philippe Lang
// Copyright (C) 2010-2013 the ChiliProject Team
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// See doc/COPYRIGHT.rdoc for more details.
//++

function halResource(apiV3:restangular.IService, $q:ng.IQService, halTransform) {
  return class HalResource {
    public $links;
    public $embedded;
    public $halTransformed: boolean = true;

    constructor(protected $source) {
      var source = this.$source.restangularized ? this.$source.plain() : angular.copy(this.$source);
      this.$links = this.transformLinks();
      this.$embedded = this.transformEmbedded();

      delete source._links;
      delete source._embedded;
      angular.extend(this, source);

      //TODO: Embedded properties should also be added
      angular.forEach(this.$links, (link, linkName) => {
        const property = {};
        angular.extend(property, link);
        this[linkName] = property;
      });
    }

    public $plain() {
      const element = angular.copy(this);
      const linked = Object.keys(this.$links);
      const props = linked.concat(Object.keys(this));
      element._links = {};

      linked.forEach(linkName => {
        element._links[linkName] = this[linkName];
        delete element._links[linkName].list;
      });

      props.forEach(propName => {
        delete element[propName];
      });

      angular.extend(element, this.$source);

      return element;
    }

    /**
     * Transform links
     *
     * Links are methods that return a promise.
     * Collections can be requested by `link[linkName].all()`.
     */
    //TODO: Implement handling for link arrays (see schema.priority._links.allowedValues)
    private transformLinks() {
      return this.transformHalProperty('_links', (links, link, linkName) => {
        const method = (method:string, multiplier:string) => {
          return (...params) => {
            if (!link.href) {
              return $q.when({});
            }

            if (method === 'post') {
              params.unshift('');
            }

            return apiV3[multiplier](linkName, link.href)[method]
              .apply(apiV3, params)
              .then((value:op.ApiResult) => {
                if (value) {
                  if (value.restangularized) {
                    value = value.plain();
                  }

                  angular.extend(this[linkName], halTransform(value));
                }

                return value;
              });
          }
        };

        if (!link.method) {
          links[linkName] = method('get', 'oneUrl');
          links[linkName].list = method('getList', 'allUrl');
        }
        else {
          links[linkName] = method(link.method, 'oneUrl');
        }

        angular.extend(links[linkName], link);
      });
    }

    /**
     * Transform embedded properties and their children to actual HAL resources,
     * if they have links or embedded resources.
     */
    private transformEmbedded() {
      return this.transformHalProperty('_embedded', (embedded, element, name) => {
        angular.forEach(element, child => child && halTransform(element));
        embedded[name] = halTransform(element);
      });
    }

    /**
     *
     * @param propertyName
     * @param callback
     * @returns {{}}
     */
    private transformHalProperty(propertyName:string, callback:(props, prop, name) => any) {
      var properties = angular.copy(this.$source[propertyName]);

      angular.forEach(properties, (property, name) => {
        callback(properties, property, name);
      });

      return properties;
    }
  }
}

angular
  .module('openproject.api')
  .factory('HalResource', halResource);