src/smartxml/transformations.js

   1 define(function(require) {
   2
   3 'use strict';
   4
   5 var _ = require('libs/underscore'),
   6     toret = {};
   7
   8 var getTransDesc = function(desc) {
   9     if(typeof desc === 'function') {
  10         desc = {impl: desc};
  11     }
  12     if(!desc.impl) {
  13         throw new Error('Got transformation description without implementation.');
  14     }
  15     return desc;
  16 };
  17
  18 toret.createGenericTransformation = function(desc, name) {
  19     desc = getTransDesc(desc);
  20
  21     var GenericTransformation = function(document, args) {
  22         this.args = args || [];
  23
  24         var transformation = this;
  25         // _.keys(this.args).forEach(function(key) {
  26         //     if(transformation.args[key].nodeType) { //@@ change to instanceof check, fix circular dependency
  27         //         var value = transformation.args[key],
  28         //             path = value.getPath();
  29         //         Object.defineProperty(transformation.args, key, {
  30         //             get: function() {
  31         //                 if(transformation.hasRun) {
  32         //                     //console.log('returning via path');
  33         //                     return transformation.document.getNodeByPath(path);
  34         //                 } else {
  35         //                     //console.log('returning original arg');
  36         //                     return value;
  37
  38         //                 }
  39         //             }
  40         //         });
  41         //     }
  42         // });
  43
  44         // potem spr na dotychczasowych undo/redo tests;
  45
  46         var patchObject = function(obj, depth) {
  47             depth = _.isNumber(depth) ? depth : 1;
  48             if(depth > 3) {
  49                 return;
  50             }
  51             _.keys(obj).forEach(function(key) {
  52                 var value = obj[key],
  53                     path;
  54                 if(value) {
  55                     if(value.nodeType) {
  56                         path = value.getPath();
  57                         Object.defineProperty(obj, key, {
  58                             get: function() {
  59                                 if(transformation.hasRun && path) {
  60                                     return transformation.document.getNodeByPath(path);
  61                                 } else {
  62                                     return value;
  63                                 }
  64                             }
  65                         });
  66                     } else if(_.isObject(value)) {
  67                         patchObject(value, depth+1);
  68                     }
  69                 }
  70             });
  71         };
  72
  73         this.args.forEach(function(arg, idx, args) {
  74             var path;
  75             if(arg) {
  76                 if(arg.nodeType) { // ~
  77                     path = arg.getPath();
  78                     Object.defineProperty(args, idx, {
  79                         get: function() {
  80                             if(transformation.hasRun && path) {
  81                                 return transformation.document.getNodeByPath(path);
  82                             } else {
  83                                 return arg;
  84                             }
  85                         }
  86                     });
  87                 } else if(_.isObject(arg)) {
  88                     patchObject(arg);
  89                 }
  90             }
  91         });
  92
  93         this.document = document;
  94         this.hasRun = false;
  95         if(desc.init) {
  96             desc.init.call(this);
  97         }
  98     };
  99     _.extend(GenericTransformation.prototype, {
 100         name: name,
 101         run: function(options) {
 102             var changeRoot;
 103             if(!desc.undo && options.beUndoable) {
 104                 changeRoot = this.getChangeRoot();
 105                 if(!changeRoot) {
 106                      throw new Error(
 107                          'Transformation {name} returned invalid change root value'
 108                          .replace('{name}', name)
 109                      );
 110                 }
 111                 this.changeRootPath = changeRoot.getPath();
 112                 this.snapshot = changeRoot.clone();
 113             }
 114             var argsToPass = desc.undo ? [this].concat(this.args) : this.args;
 115             var toret = desc.impl.apply(this.context, argsToPass);
 116             this.hasRun = true;
 117             return toret;
 118         },
 119         undo: function() {
 120             if(desc.undo) {
 121                 desc.undo.call(this.context, this);
 122             } else {
 123                 this.document.getNodeByPath(this.changeRootPath).replaceWith(this.snapshot);
 124             }
 125         },
 126         getChangeRoot: desc.getChangeRoot || function() {
 127             return this.document.root;
 128         }
 129     });
 130
 131     return GenericTransformation;
 132 };
 133
 134 toret.createContextTransformation = function(desc, name) {
 135     var GenericTransformation = toret.createGenericTransformation(desc, name);
 136
 137     var ContextTransformation = function(document, object, args) {
 138         GenericTransformation.call(this, document, args);
 139
 140         if(document === object) {
 141             this.context = document;
 142         } else {
 143             var contextPath = object.getPath(),
 144                 transformation = this;
 145             Object.defineProperty(this, 'context', {
 146                 get: function() {
 147                     if(transformation.hasRun) {
 148                         return transformation.document.getNodeByPath(contextPath);
 149                     } else {
 150                         return object;
 151                     }
 152                 }
 153             });
 154         }
 155     };
 156     ContextTransformation.prototype = Object.create(GenericTransformation.prototype);
 157     return ContextTransformation;
 158 };
 159
 160 return toret;
 161
 162 });