openproject/frontend/app/components/api/api-v3/hal-resources/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.
//++

import {opApiModule} from "../../../../angular-modules";

var $q;
var lazy;
var halTransform;
var HalLink;

export class HalResource {
  public $isHal:boolean = true;
  public $self:ng.IPromise<HalResource>;

  private _name:string;
  private _$links:any;
  private _$embedded:any;

  public static fromLink(link) {
    var resource = HalResource.getEmptyResource();
    resource._links.self = link;

    resource = halTransform(resource);
    resource.$loaded = false;

    return resource;
  }

  protected static getEmptyResource():any {
    return {_links: {self: {href: null}}};
  }

  public get name():string {
    return this._name || this.$links.self.$link.title || '';
  }

  public set name(name:string) {
    this._name = name;
  }

  public get href():string|void {
    if (this.$links.self) return this.$links.self.$link.href;
  }

  public get $links() {
    return this.setupProperty('links',
      link => Array.isArray(link) ? link.map(HalLink.asFunc) : HalLink.asFunc(link));
  }

  public get $embedded() {
    return this.setupProperty('embedded', element => {
      angular.forEach(element, (child, name:string) => {
        if (child) {
          lazy(element, name, () => halTransform(child));
        }
      });

      if (Array.isArray(element)) {
        return element.map(halTransform);
      }

      return halTransform(element);
    });
  }

  constructor(public $source:any = HalResource.getEmptyResource(), public $loaded:boolean = true) {
    this.$source = $source._plain || $source;

    this.proxyProperties();
    this.setLinksAsProperties();
    this.setEmbeddedAsProperties();
  }

  public $load() {
    if (this.$loaded) {
      return $q.when(this);
    }

    if (!this.$loaded && this.$self) {
      return this.$self;
    }

    this.$self = this.$links.self().then(resource => {
      this.$loaded = true;
      angular.extend(this, resource);

      return this;
    });

    return this.$self;
  }


  public $plain() {
    return angular.copy(this.$source);
  }

  private proxyProperties() {
    _.without(Object.keys(this.$source), '_links', '_embedded').forEach(property => {
      Object.defineProperty(this, property, {
        get() {
          return this.$source[property];
        },
        set(value) {
          this.$source[property] = value;
        },

        enumerable: true
      });
    });
  }

  private setLinksAsProperties() {
    _.without(Object.keys(this.$links), 'self').forEach(linkName => {
      lazy(this, linkName,
        () => {
          let link = this.$links[linkName].$link || this.$links[linkName];

          if (Array.isArray(link)) {
            return link.map(item => HalResource.fromLink(item));
          }

          if (link.href) {
            if (link.method !== 'get') {
              return HalLink.asFunc(link);
            }
            return HalResource.fromLink(link);
          }
        },
        val => {
          if (val && val.$links && val.$links.self) {
            let link = val.$links.self.$link;

            if (link && link.href && link.method === 'get') {
              if (val && val.$isHal) {
                this.$source._links[linkName] = val.$links.self.$link;
              }

              return val;
            }
          }
        })
    });
  }

  private setEmbeddedAsProperties() {
    Object.keys(this.$embedded).forEach(name => {
      lazy(this, name, () => this.$embedded[name], val => val);
    });
  }

  private setupProperty(name:string, callback:(element:any) => any) {
    let instanceName = '_$' + name;
    let sourceName = '_' + name;
    let sourceObj = this.$source[sourceName];

    if (!this[instanceName] && angular.isObject(sourceObj)) {
      this[instanceName] = {};

      Object.keys(sourceObj).forEach(propName => {
        lazy(this[instanceName], propName, () => callback(sourceObj[propName]));
      });
    }

    return this[instanceName] || {};
  }
}

function halResource(_$q_, _lazy_, _halTransform_, _HalLink_) {
  $q = _$q_;
  lazy = _lazy_;
  halTransform = _halTransform_;
  HalLink = _HalLink_;

  return HalResource;
}

opApiModule.factory('HalResource', ['$q', 'lazy', 'halTransform', 'HalLink', halResource]);