editor: canvas - refactoring

[fnpeditor.git] / src / smartxml / smartxml.js

diff --git a/src/smartxml/smartxml.js b/src/smartxml/smartxml.js
index 91dd8bb..35c5299 100644 (file)
--- a/src/smartxml/smartxml.js
+++ b/src/smartxml/smartxml.js
@@ -2,13 +2,13 @@ define([
     'libs/jquery',
     'libs/underscore',
     'libs/backbone',
     'libs/jquery',
     'libs/underscore',
     'libs/backbone',

-    'smartxml/events'
-], function($, _, Backbone, events) {
+    'smartxml/events',
+    'smartxml/transformations',
+    'smartxml/core'
+], function($, _, Backbone, events, transformations, coreTransformations) {

     
 'use strict';
     
 'use strict';

-
-
-var TEXT_NODE = Node.TEXT_NODE;
+/* globals Node */

 
 
 var DocumentNode = function(nativeNode, document) {
 
 
 var DocumentNode = function(nativeNode, document) {


@@ -21,49 +21,132 @@ var DocumentNode = function(nativeNode, document) {
 };
 
 $.extend(DocumentNode.prototype, {
 };
 
 $.extend(DocumentNode.prototype, {

+
+    transform: function(Transformation, args) {
+        var transformation = new Transformation(this.document, this, args);
+        return this.document.transform(transformation);
+    },
+

     _setNativeNode: function(nativeNode) {
         this.nativeNode = nativeNode;
         this._$ = $(nativeNode);
     },
 
     _setNativeNode: function(nativeNode) {
         this.nativeNode = nativeNode;
         this._$ = $(nativeNode);
     },
 

-    detach: function() { this._$.detach(); },
+    clone: function() {
+        var clone = this._$.clone(true, true),
+            node = this;
+        clone.find('*').addBack().each(function() {
+            var el = this,
+                clonedData = $(this).data();
+
+            _.pairs(clonedData).forEach(function(pair) {
+                var key = pair[0],
+                    value = pair[1];
+                if(_.isFunction(value.clone)) {
+                    clonedData[key] = value.clone(node.document.createDocumentNode(el));
+                }
+            });
+        });
+        return this.document.createDocumentNode(clone[0]);
+    },
+
+    getPath: function(ancestor) {
+        if(!(this.document.containsNode(this))) {
+            return null;
+        }
+
+        var nodePath = [this].concat(this.parents()),
+            toret, idx;
+        ancestor = ancestor || this.document.root;
+
+        nodePath.some(function(node, i) {
+            if(node.sameNode(ancestor)) {
+                idx = i;
+                return true;
+            }
+        });
+
+        if(idx !== undefined) {
+            nodePath = nodePath.slice(0, idx);
+        }
+        toret = nodePath.map(function(node) {return node.getIndex(); });
+        toret.reverse();
+        return toret;
+    },
+
+    isRoot: function() {
+        return this.document.root.sameNode(this);
+    },

 
     sameNode: function(otherNode) {
 
     sameNode: function(otherNode) {

-        return otherNode && this.nativeNode === otherNode.nativeNode;
+        return !!(otherNode) && this.nativeNode === otherNode.nativeNode;

     },
 
     parent: function() {
     },
 
     parent: function() {

-        return this.nativeNode.parentNode ? this.document.createElementNode(this.nativeNode.parentNode) : null;
+        var parentNode = this.nativeNode.parentNode;
+        if(parentNode && parentNode.nodeType === Node.ELEMENT_NODE) {
+            return this.document.createDocumentNode(parentNode);
+        }
+        return null;

     },
 
     },
 

-    after: function(node) {
-        node = node instanceof ElementNode ? node : this.document.createElementNode(node);
-        this._$.after(node.nativeNode);
-        return node;
+    parents: function() {
+        var parent = this.parent(),
+            parents = parent ? parent.parents() : [];
+        if(parent) {
+            parents.unshift(parent);
+        }
+        return parents;

     },
 
     },
 

-    before: function(node) {
-        node = node instanceof ElementNode ? node : this.document.createElementNode(node);
-        this._$.before(node.nativeNode);
-        return node;
+    prev: function() {
+        var myIdx = this.getIndex();
+        return myIdx > 0 ? this.parent().contents()[myIdx-1] : null;

     },
 
     },
 

-    wrapWith: function(node) {
-        node = node instanceof ElementNode ? node : this.document.createElementNode(node);
-
-        if(this.parent()) {
-            this.before(node);
+    next: function() {
+        if(this.isRoot()) {
+            return null;

         }
         }

-        node.append(this);
-        return node;
+        var myIdx = this.getIndex(),
+            parentContents = this.parent().contents();
+        return myIdx < parentContents.length - 1 ? parentContents[myIdx+1] : null;

     },
 
     },
 

-    triggerChangeEvent: function(type, metaData) {
-        var event = new events.ChangeEvent(type, $.extend({node: this}, metaData || {}));
-        this.document.trigger('change', event);
+    isSurroundedByTextElements: function() {
+        var prev = this.prev(),
+            next = this.next();
+        return prev && (prev.nodeType === Node.TEXT_NODE) && next && (next.nodeType === Node.TEXT_NODE);

     },
     },

+
+    triggerChangeEvent: function(type, metaData, origParent, nodeWasContained) {
+        var node = (metaData && metaData.node) ? metaData.node : this,
+            event = new events.ChangeEvent(type, $.extend({node: node}, metaData || {}));
+        if(type === 'nodeDetached' || this.document.containsNode(event.meta.node)) {
+            if(type === 'nodeMoved') {
+                event.meta.parent = origParent;
+            }
+            this.document.trigger('change', event);
+        }
+        if((type === 'nodeAdded' || type === 'nodeMoved') && !this.document.containsNode(this) && nodeWasContained) {
+             event = new events.ChangeEvent('nodeDetached', {node: node, parent: origParent});
+             this.document.trigger('change', event);
+        }
+    },
+    
+    getNodeInsertion: function(node) {
+        return this.document.getNodeInsertion(node);
+    },
+
+    getIndex: function() {
+        if(this.isRoot()) {
+            return 0;
+        }
+        return this.parent().indexOf(this);
+    }

 });
 
 });
 

+

 var ElementNode = function(nativeNode, document) {
     DocumentNode.call(this, nativeNode, document);
 };
 var ElementNode = function(nativeNode, document) {
     DocumentNode.call(this, nativeNode, document);
 };


@@ -92,17 +175,18 @@ $.extend(ElementNode.prototype, {
         return this.nativeNode.tagName.toLowerCase();
     },
 
         return this.nativeNode.tagName.toLowerCase();
     },
 

-    contents: function() {
+    contents: function(selector) {

         var toret = [],
             document = this.document;
         var toret = [],
             document = this.document;

-        this._$.contents().each(function() {
-            if(this.nodeType === Node.ELEMENT_NODE) {
-                toret.push(document.createElementNode(this));
-            }
-            else if(this.nodeType === Node.TEXT_NODE) {
-                toret.push(document.createTextNode(this));
-            }
-        });
+        if(selector) {
+            this._$.children(selector).each(function() {
+                toret.push(document.createDocumentNode(this));
+            });
+        } else {
+            this._$.contents().each(function() {
+                toret.push(document.createDocumentNode(this));
+            });
+        }

         return toret;
     },
 
         return toret;
     },
 


@@ -110,37 +194,10 @@ $.extend(ElementNode.prototype, {
         return this._$.contents().index(node._$);
     },
 
         return this._$.contents().index(node._$);
     },
 

-    setTag: function(tagName) {
-        var node = this.document.createElementNode({tagName: tagName}),
-            oldTagName = this.getTagName(),
-            myContents = this._$.contents();
-
-        this.getAttrs().forEach(function(attribute) {
-            node.setAttr(attribute.name, attribute.value, true);
-        });
-        node.setData(this.getData());
-
-        if(this.sameNode(this.document.root)) {
-            defineDocumentProperties(this.document, node._$);
-        }
-        this._$.replaceWith(node._$);
-        this._setNativeNode(node._$[0]);
-        this._$.append(myContents);
-        this.triggerChangeEvent('nodeTagChange', {oldTagName: oldTagName, newTagName: this.getTagName()});
-    },
-

     getAttr: function(name) {
         return this._$.attr(name);
     },
 
     getAttr: function(name) {
         return this._$.attr(name);
     },
 

-    setAttr: function(name, value, silent) {
-        var oldVal = this.getAttr(name);
-        this._$.attr(name, value);
-        if(!silent) {
-            this.triggerChangeEvent('nodeAttrChange', {attr: name, oldVal: oldVal, newVal: value});
-        }
-    },
-

     getAttrs: function() {
         var toret = [];
         for(var i = 0; i < this.nativeNode.attributes.length; i++) {
     getAttrs: function() {
         var toret = [];
         for(var i = 0; i < this.nativeNode.attributes.length; i++) {


@@ -149,64 +206,8 @@ $.extend(ElementNode.prototype, {
         return toret;
     },
 
         return toret;
     },
 

-    append: function(node) {
-        node = node instanceof DocumentNode ? node : this.document.createElementNode(node);
-        this._$.append(node.nativeNode);
-    },
-
-    prepend: function(node) {
-        node = node instanceof DocumentNode ? node : this.document.createElementNode(node);
-        this._$.prepend(node.nativeNode);
-    },
-
-    unwrapContent: function() {
-        var parent = this.parent();
-        if(!parent) {
-            return;
-        }
-
-        var parentContents = parent.contents(),
-            myContents = this.contents(),
-            myIdx = parent.indexOf(this);
-
-        if(myContents.length === 0) {
-            return this.detach();
-        }
-
-        var moveLeftRange, moveRightRange, leftMerged;
-
-        if(myIdx > 0 && (parentContents[myIdx-1].nodeType === TEXT_NODE) && (myContents[0].nodeType === TEXT_NODE)) {
-            parentContents[myIdx-1].appendText(myContents[0].getText());
-            myContents[0].detach();
-            moveLeftRange = true;
-            leftMerged = true;
-        } else {
-            leftMerged = false;
-        }
-
-        if(!(leftMerged && myContents.length === 1)) {
-            if(myIdx < parentContents.length - 1 && (parentContents[myIdx+1].nodeType === TEXT_NODE) && (myContents[myContents.length-1].nodeType === TEXT_NODE)) {
-                parentContents[myIdx+1].prependText(myContents[myContents.length-1].getText());
-                myContents[myContents.length-1].detach();
-                moveRightRange = true;
-            }
-        }
-
-        var childrenLength = this.contents().length;
-        this.contents().forEach(function(child) {
-            this.before(child);
-        }.bind(this));
-
-        this.detach();
-
-        return {
-            element1: parent.contents()[myIdx + (moveLeftRange ? -1 : 0)],
-            element2: parent.contents()[myIdx + childrenLength-1 + (moveRightRange ? 1 : 0)]
-        };
-    },
-
-    wrapText: function(params) {
-        return this.document._wrapText(_.extend({inside: this}, params));
+    containsNode: function(node) {
+        return node && (node.nativeNode === this.nativeNode || node._$.parents().index(this._$) !== -1);

     },
 
     toXML: function() {
     },
 
     toXML: function() {


@@ -220,6 +221,7 @@ $.extend(ElementNode.prototype, {
     }
 });
 
     }
 });
 

+

 var TextNode = function(nativeNode, document) {
     DocumentNode.call(this, nativeNode, document);
 };
 var TextNode = function(nativeNode, document) {
     DocumentNode.call(this, nativeNode, document);
 };


@@ -232,35 +234,6 @@ $.extend(TextNode.prototype, {
         return this.nativeNode.data;
     },
 
         return this.nativeNode.data;
     },
 

-    setText: function(text) {
-        this.nativeNode.data = text;
-        this.triggerTextChangeEvent();
-    },
-
-    appendText: function(text) {
-        this.nativeNode.data = this.nativeNode.data + text;
-        this.triggerTextChangeEvent();
-    },
-
-    prependText: function(text) {
-        this.nativeNode.data = text + this.nativeNode.data;
-        this.triggerTextChangeEvent();
-    },
-
-    wrapWith: function(desc) {
-        if(typeof desc.start === 'number' && typeof desc.end === 'number') {
-            return this.document._wrapText({
-                inside: this.parent(),
-                textNodeIdx: this.parent().indexOf(this),
-                offsetStart: Math.min(desc.start, desc.end),
-                offsetEnd: Math.max(desc.start, desc.end),
-                _with: {tag: desc.tagName, attrs: desc.attrs}
-            });
-        } else {
-            return DocumentNode.prototype.wrapWith.call(this, desc);
-        }
-    },
-

     triggerTextChangeEvent: function() {
         var event = new events.ChangeEvent('nodeTextChange', {node: this});
         this.document.trigger('change', event);
     triggerTextChangeEvent: function() {
         var event = new events.ChangeEvent('nodeTextChange', {node: this});
         this.document.trigger('change', event);


@@ -269,10 +242,52 @@ $.extend(TextNode.prototype, {
 
 
 var parseXML = function(xml) {
 
 
 var parseXML = function(xml) {

-    return $(xml)[0];
+    var toret = $($.trim(xml));
+    if(!toret.length) {
+        throw new Error('Unable to parse XML: ' + xml);
+    }
+    return toret[0];
+
+};
+
+var registerTransformation = function(desc, name, target) {
+    var Transformation = transformations.createContextTransformation(desc, name);
+    target[name] = function() {
+        var instance = this,
+            args = Array.prototype.slice.call(arguments, 0);
+        return instance.transform(Transformation, args);
+    };

 };
 
 };
 

-var Document = function(xml) {
+var registerMethod = function(methodName, method, target) {
+    if(target[methodName]) {
+        throw new Error('Cannot extend {target} with method name {methodName}. Name already exists.'
+            .replace('{target}', target)
+            .replace('{methodName}', methodName)
+        );
+    }
+    target[methodName] = method;
+};
+
+
+var Document = function(xml, extensions) {
+    this.undoStack = [];
+    this.redoStack = [];
+    this._currentTransaction = null;
+    this._transformationLevel = 0;
+    
+    this._nodeMethods = {};
+    this._textNodeMethods = {};
+    this._elementNodeMethods = {};
+    this._nodeTransformations = {};
+    this._textNodeTransformations = {};
+    this._elementNodeTransformations = {};
+    
+    this.registerExtension(coreTransformations);
+
+    (extensions || []).forEach(function(extension) {
+        this.registerExtension(extension);
+    }.bind(this));

     this.loadXML(xml);
 };
 
     this.loadXML(xml);
 };
 


@@ -280,102 +295,354 @@ $.extend(Document.prototype, Backbone.Events, {
     ElementNodeFactory: ElementNode,
     TextNodeFactory: TextNode,
 
     ElementNodeFactory: ElementNode,
     TextNodeFactory: TextNode,
 

-    createElementNode: function(from) {
-        if(!(from instanceof HTMLElement)) {
-            if(from.text) {
-                from = document.createTextNode(from.text);
+    createDocumentNode: function(from) {
+        if(!(from instanceof Node)) {
+            if(typeof from === 'string') {
+                from = parseXML(from);
+                this.normalizeXML(from);

             } else {
             } else {

-                var node = $('<' + from.tagName + '>');
-
-                _.keys(from.attrs || {}).forEach(function(key) {
-                    node.attr(key, from.attrs[key]);
-                });
-
-                from = node[0];
+                if(from.text !== undefined) {
+                    /* globals document */
+                    from = document.createTextNode(from.text);
+                } else {
+                    if(!from.tagName) {
+                        throw new Error('tagName missing');
+                    }
+                    var node = $('<' + from.tagName + '>');
+
+                    _.keys(from.attrs || {}).forEach(function(key) {
+                        node.attr(key, from.attrs[key]);
+                    });
+
+                    from = node[0];
+                }

             }
         }
             }
         }

-        return new this.ElementNodeFactory(from, this);
-    },
+        var Factory, typeMethods, typeTransformations;
+        if(from.nodeType === Node.TEXT_NODE) {
+            Factory = this.TextNodeFactory;
+            typeMethods = this._textNodeMethods;
+            typeTransformations = this._textNodeTransformations;
+        } else if(from.nodeType === Node.ELEMENT_NODE) {
+            Factory = this.ElementNodeFactory;
+            typeMethods = this._elementNodeMethods;
+            typeTransformations = this._elementNodeTransformations;
+        }
+        var toret = new Factory(from, this);
+        _.extend(toret, this._nodeMethods);
+        _.extend(toret, typeMethods);
+        
+        _.extend(toret, this._nodeTransformations);
+        _.extend(toret, typeTransformations);
+        
+        toret.__super__ = _.extend({}, this._nodeMethods, this._nodeTransformations);
+        _.keys(toret.__super__).forEach(function(key) {
+            toret.__super__[key] = _.bind(toret.__super__[key], toret);
+        });

 
 

-    createTextNode: function(nativeNode) {
-        return new this.TextNodeFactory(nativeNode, this);
+        return toret;

     },
 
     loadXML: function(xml, options) {
         options = options || {};
     },
 
     loadXML: function(xml, options) {
         options = options || {};

-        defineDocumentProperties(this, $(parseXML(xml)));
+        this._defineDocumentProperties($(parseXML(xml)));
+        this.normalizeXML(this.dom);

         if(!options.silent) {
             this.trigger('contentSet');
         }
     },
 
         if(!options.silent) {
             this.trigger('contentSet');
         }
     },
 

+    normalizeXML: function(nativeNode) {
+        void(nativeNode); // noop
+    },
+

     toXML: function() {
         return this.root.toXML();
     },
 
     toXML: function() {
         return this.root.toXML();
     },
 

-    _wrapText: function(params) {
-        params = _.extend({textNodeIdx: 0}, params);
-        if(typeof params.textNodeIdx === 'number') {
-            params.textNodeIdx = [params.textNodeIdx];
+    containsNode: function(node) {
+        return this.root && this.root.containsNode(node);
+    },
+
+    getSiblingParents: function(params) {
+        var parents1 = [params.node1].concat(params.node1.parents()).reverse(),
+            parents2 = [params.node2].concat(params.node2.parents()).reverse(),
+            noSiblingParents = null;
+
+        if(parents1.length === 0 || parents2.length === 0 || !(parents1[0].sameNode(parents2[0]))) {
+            return noSiblingParents;

         }
         }

-        
-        var contentsInside = params.inside.contents(),
-            idx1 = Math.min.apply(Math, params.textNodeIdx),
-            idx2 = Math.max.apply(Math, params.textNodeIdx),
-            textNode1 = contentsInside[idx1],
-            textNode2 = contentsInside[idx2],
-            sameNode = textNode1.sameNode(textNode2),
-            prefixOutside = textNode1.getText().substr(0, params.offsetStart),
-            prefixInside = textNode1.getText().substr(params.offsetStart),
-            suffixInside = textNode2.getText().substr(0, params.offsetEnd),
-            suffixOutside = textNode2.getText().substr(params.offsetEnd)
-        ;
-
-        if(!(textNode1.parent().sameNode(textNode2.parent()))) {
-            throw new Error('Wrapping text in non-sibling text nodes not supported.');
+
+        var stop = Math.min(parents1.length, parents2.length),
+            i;
+        for(i = 0; i < stop; i++) {
+            if(parents1[i].sameNode(parents2[i])) {
+                continue;
+            }
+            break;

         }
         }

-        
-        var wrapperElement = this.createElementNode({tagName: params._with.tag, attrs: params._with.attrs});
-        textNode1.after(wrapperElement);
-        textNode1.detach();
-        
-        if(prefixOutside.length > 0) {
-            wrapperElement.before({text:prefixOutside});
+        if(i === stop) {
+            i--;

         }
         }

-        if(sameNode) {
-            var core = textNode1.getText().substr(params.offsetStart, params.offsetEnd - params.offsetStart);
-            wrapperElement.append({text: core});
+        return {node1: parents1[i], node2: parents2[i]};
+    },
+
+    trigger: function() {
+        Backbone.Events.trigger.apply(this, arguments);
+    },
+
+    getNodeInsertion: function(node) {
+        var insertion = {};
+        if(node instanceof DocumentNode) {
+            insertion.ofNode = node;
+            insertion.insertsNew = !this.containsNode(node);

         } else {
         } else {

-            textNode2.detach();
-            if(prefixInside.length > 0) {
-                wrapperElement.append({text: prefixInside});
+          insertion.ofNode = this.createDocumentNode(node);
+          insertion.insertsNew = true;
+        }
+        return insertion;
+    },
+
+    registerMethod: function(methodName, method, dstName) {
+        var doc = this;
+        var destination = {
+            document: doc,
+            documentNode: doc._nodeMethods,
+            textNode: doc._textNodeMethods,
+            elementNode: doc._elementNodeMethods
+        }[dstName];
+        registerMethod(methodName, method, destination);
+    },
+
+    registerTransformation: function(desc, name, dstName) {
+        var doc = this;
+        var destination = {
+            document: doc,
+            documentNode: doc._nodeTransformations,
+            textNode: doc._textNodeTransformations,
+            elementNode: doc._elementNodeTransformations
+        }[dstName];
+        registerTransformation(desc, name, destination);
+    },
+
+    registerExtension: function(extension) {
+        var doc = this;
+
+        ['document', 'documentNode', 'elementNode', 'textNode'].forEach(function(dstName) {
+            var dstExtension = extension[dstName];
+            if(dstExtension) {
+                if(dstExtension.methods) {
+                    _.pairs(dstExtension.methods).forEach(function(pair) {
+                        var methodName = pair[0],
+                            method = pair[1];
+
+                        doc.registerMethod(methodName, method, dstName);
+
+                    });
+                }
+
+                if(dstExtension.transformations) {
+                    _.pairs(dstExtension.transformations).forEach(function(pair) {
+                        var name = pair[0],
+                            desc = pair[1];
+                        doc.registerTransformation(desc, name, dstName);
+                    });
+                }

             }
             }

-            for(var i = idx1 + 1; i < idx2; i++) {
-                wrapperElement.append(contentsInside[i]);
+        });
+    },
+
+    ifChanged: function(context, action, documentChangedHandler, documentUnchangedHandler) {
+        var hasChanged = false,
+            changeMonitor = function() {
+                hasChanged = true;
+            };
+
+        this.on('change', changeMonitor);
+        action.call(context);
+        this.off('change', changeMonitor);
+        
+        if(hasChanged) {
+            if(documentChangedHandler) {
+                documentChangedHandler.call(context);

             }
             }

-            if(suffixInside.length > 0) {
-                wrapperElement.append({text: suffixInside});
+        } else {
+            if(documentUnchangedHandler) {
+                documentUnchangedHandler.call(context);

             }
         }
             }
         }

-        if(suffixOutside.length > 0) {
-            wrapperElement.after({text: suffixOutside});
+    },
+
+    transform: function(Transformation, args) {
+        var toret, transformation;
+
+        if(!this._currentTransaction) {
+            return this.transaction(function() {
+                return this.transform(Transformation, args);
+            }, this);
+        }
+
+        if(typeof Transformation === 'function') {
+            transformation = new Transformation(this, this, args);
+        } else {
+            transformation = Transformation;
+        }
+        if(transformation) {
+            this._transformationLevel++;
+            
+            this.ifChanged(
+                this,
+                function() {
+                    toret = transformation.run({beUndoable:this._transformationLevel === 1});
+                },
+                function() {
+                    if(this._transformationLevel === 1 && !this._undoInProgress) {
+                        this._currentTransaction.pushTransformation(transformation);
+                        this.redoStack = [];
+                    }
+                }
+            );
+
+            this._transformationLevel--;
+            return toret;
+        } else {
+            throw new Error('Transformation ' + transformation + ' doesn\'t exist!');
+        }
+    },
+    undo: function() {
+        var transaction = this.undoStack.pop(),
+            doc = this,
+            transformations, stopAt;
+
+        if(transaction) {
+            this._undoInProgress = true;
+
+            // We will modify this array in a minute so make sure we work on a copy.
+            transformations = transaction.transformations.slice(0);
+
+            if(transformations.length > 1) {
+                // In case of real transactions we don't want to run undo on all of transformations if we don't have to.
+                stopAt = undefined;
+                transformations.some(function(t, idx) {
+                    if(!t.undo && t.getChangeRoot().sameNode(doc.root)) {
+                        stopAt = idx;
+                        return true; //break
+                    }
+                });
+                if(stopAt !== undefined) {
+                    // We will get away with undoing only this transformations as the one at stopAt reverses the whole document.
+                    transformations = transformations.slice(0, stopAt+1);
+                }
+            }
+
+            transformations.reverse();
+            transformations.forEach(function(t) {
+                t.undo();
+            });
+
+            this._undoInProgress = false;
+            this.redoStack.push(transaction);
+        }
+    },
+    redo: function() {
+        var transaction = this.redoStack.pop();
+        if(transaction) {
+            this._transformationLevel++;
+            transaction.transformations.forEach(function(t) {
+                t.run({beUndoable: true});
+            });
+            this._transformationLevel--;
+            this.undoStack.push(transaction);
+        }
+    },
+
+    startTransaction: function(metadata) {
+        if(this._currentTransaction) {
+            throw new Error('Nested transactions not supported!');
+        }
+        this._rollbackBackup = this.root.clone();
+        this._currentTransaction = new Transaction([], metadata);
+    },
+
+    endTransaction: function() {
+        if(!this._currentTransaction) {
+            throw new Error('End of transaction requested, but there is no transaction in progress!');
+        }
+        if(this._currentTransaction.hasTransformations()) {
+            this.undoStack.push(this._currentTransaction);
+        }
+        this._currentTransaction = null;
+    },
+
+    rollbackTransaction: function() {
+        if(!this._currentTransaction) {
+            throw new Error('Transaction rollback requested, but there is no transaction in progress!');

         }
         }

-        return wrapperElement;
+        this.replaceRoot(this._rollbackBackup);
+        this._rollbackBackup = null;
+        this._currentTransaction = null;
+    },
+
+    transaction: function(callback, params) {
+        var toret;
+        params = params || {};
+        this.startTransaction(params.metadata);
+        try {
+            toret = callback.call(params.context || this);
+        } catch(e) {
+            if(params.error) {
+                params.error(e);
+            }
+            this.rollbackTransaction();
+            return;
+        }
+        this.endTransaction();
+        return toret;
+    },
+
+    getNodeByPath: function(path) {
+        var toret = this.root;
+        path.forEach(function(idx) {
+            toret = toret.contents()[idx];
+        });
+        return toret;
+    },
+
+    _defineDocumentProperties: function($document) {
+        var doc = this;
+        Object.defineProperty(doc, 'root', {get: function() {
+            if(!$document) {
+                return null;
+            }
+            return doc.createDocumentNode($document[0]);
+        }, configurable: true});
+        Object.defineProperty(doc, 'dom', {get: function() {
+            if(!$document) {
+                return null;
+            }
+            return $document[0];
+        }, configurable: true});

     }
 });
 
     }
 });
 

-var defineDocumentProperties = function(doc, $document) {
-    Object.defineProperty(doc, 'root', {get: function() {
-        return doc.createElementNode($document[0]);
-    }, configurable: true});
-    Object.defineProperty(doc, 'dom', {get: function() {
-        return $document[0];
-    }, configurable: true});
+var Transaction = function(transformations, metadata) {
+    this.transformations = transformations || [];
+    this.metadata = metadata;

 };
 };

+$.extend(Transaction.prototype, {
+    pushTransformation: function(transformation) {
+        this.transformations.push(transformation);
+    },
+    hasTransformations: function() {
+        return this.transformations.length > 0;
+    }
+});
+

 
 return {
     documentFromXML: function(xml) {
 
 return {
     documentFromXML: function(xml) {

-        return new Document(parseXML(xml));
+        var doc = new Document(xml);
+        return doc;

     },
 
     elementNodeFromXML: function(xml) {
     },
 
     elementNodeFromXML: function(xml) {


@@ -384,7 +651,8 @@ return {
 
     Document: Document,
     DocumentNode: DocumentNode,
 
     Document: Document,
     DocumentNode: DocumentNode,

-    ElementNode: ElementNode
+    ElementNode: ElementNode,
+    TextNode: TextNode

 };
 
 });
\ No newline at end of file
 };
 
 });
\ No newline at end of file