X-Git-Url: https://git.mdrn.pl/fnpeditor.git/blobdiff_plain/0f5cbf957bc0bbdcff93bdb33c227f78041e332b..8244aae227025150a77d6377caa52e0b7b0b5cbc:/src/smartxml/smartxml.js

diff --git a/src/smartxml/smartxml.js b/src/smartxml/smartxml.js
index 9215287..505ab85 100644
--- a/src/smartxml/smartxml.js
+++ b/src/smartxml/smartxml.js
@@ -3,29 +3,13 @@ define([
     'libs/underscore',
     'libs/backbone',
     'smartxml/events',
-    'smartxml/transformations'
-], function($, _, Backbone, events, transformations) {
+    'smartxml/transformations',
+    'smartxml/core'
+], function($, _, Backbone, events, transformations, coreTransformations) {
     
 'use strict';
 /* globals Node */
 
-var TEXT_NODE = Node.TEXT_NODE;
-
-
-var INSERTION = function(implementation) {
-    var toret = function(node) {
-        var insertion = this.getNodeInsertion(node),
-            nodeWasContained = this.document.containsNode(insertion.ofNode),
-            nodeParent;
-        if(!(this.document.containsNode(this))) {
-            nodeParent = insertion.ofNode.parent();
-        }
-        implementation.call(this, insertion.ofNode.nativeNode);
-        this.triggerChangeEvent(insertion.insertsNew ? 'nodeAdded' : 'nodeMoved', {node: insertion.ofNode}, nodeParent, nodeWasContained);
-        return insertion.ofNode;
-    };
-    return toret;
-};
 
 var DocumentNode = function(nativeNode, document) {
     if(!document) {
@@ -38,12 +22,8 @@ var DocumentNode = function(nativeNode, document) {
 
 $.extend(DocumentNode.prototype, {
 
-    transform: function(name, args) {
-        var Transformation = this.transformations.get(name),
-            transformation;
-        if(Transformation) {
-            transformation = new Transformation(this.document, this, args);
-        }
+    transform: function(Transformation, args) {
+        var transformation = new Transformation(this.document, this, args);
         return this.document.transform(transformation);
     },
 
@@ -53,18 +33,28 @@ $.extend(DocumentNode.prototype, {
     },
 
     clone: function() {
-        var clone = this._$.clone(true, true);
-        // clone.find('*').addBack().each(function() {
-        //     var n = $(this);
-        //     if(n.data('canvasElement')) {
-        //         n.data('canvasElement', $.extend(true, {}, n.data('canvasElement')));
-        //         n.data('canvasElement').$element = n.data('canvasElement').$element.clone(true, true);
-        //     }
-        // });
+        var clone = this._$.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;
@@ -76,7 +66,7 @@ $.extend(DocumentNode.prototype, {
             }
         });
 
-        if(idx !== 'undefined') {
+        if(idx !== undefined) {
             nodePath = nodePath.slice(0, idx);
         }
         toret = nodePath.map(function(node) {return node.getIndex(); });
@@ -88,23 +78,6 @@ $.extend(DocumentNode.prototype, {
         return this.document.root.sameNode(this);
     },
 
-    detach: function() {
-        var parent = this.parent();
-        this._$.detach();
-        this.triggerChangeEvent('nodeDetached', {parent: parent});
-        return this;
-    },
-
-    replaceWith: function(node) {
-        var toret;
-        if(this.isRoot()) {
-            return this.document.replaceRoot(node);
-        }
-        toret = this.after(node);
-        this.detach();
-        return toret;
-    },
-
     sameNode: function(otherNode) {
         return !!(otherNode) && this.nativeNode === otherNode.nativeNode;
     },
@@ -146,43 +119,13 @@ $.extend(DocumentNode.prototype, {
         return prev && (prev.nodeType === Node.TEXT_NODE) && next && (next.nodeType === Node.TEXT_NODE);
     },
 
-    after: INSERTION(function(nativeNode) {
-        return this._$.after(nativeNode);
-    }),
-
-    before: INSERTION(function(nativeNode) {
-        return this._$.before(nativeNode);
-    }),
-
-    wrapWith: function(node) {
-        var insertion = this.getNodeInsertion(node);
-        if(this.parent()) {
-            this.before(insertion.ofNode);
-        }
-        insertion.ofNode.append(this);
-        return insertion.ofNode;
-    },
-
-    /**
-    * Removes parent of a node if node has no siblings.
-    */
-    unwrap: function() {
-        if(this.isRoot()) {
-            return;
-        }
-        var parent = this.parent(),
-            grandParent;
-        if(parent.contents().length === 1) {
-            grandParent = parent.parent();
-            parent.unwrapContent();
-            return grandParent;
-        }
-    },
-
     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) {
@@ -203,6 +146,7 @@ $.extend(DocumentNode.prototype, {
     }
 });
 
+
 var ElementNode = function(nativeNode, document) {
     DocumentNode.call(this, nativeNode, document);
 };
@@ -211,16 +155,6 @@ ElementNode.prototype = Object.create(DocumentNode.prototype);
 $.extend(ElementNode.prototype, {
     nodeType: Node.ELEMENT_NODE,
 
-    detach: function() {
-        var next;
-        if(this.parent() && this.isSurroundedByTextElements()) {
-            next = this.next();
-            this.prev().appendText(next.getText());
-            next.detach();
-        }
-        return DocumentNode.prototype.detach.call(this);
-    },
-
     setData: function(key, value) {
         if(value !== undefined) {
             this._$.data(key, value);
@@ -260,37 +194,10 @@ $.extend(ElementNode.prototype, {
         return this._$.contents().index(node._$);
     },
 
-    setTag: function(tagName) {
-        var node = this.document.createDocumentNode({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);
     },
 
-    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++) {
@@ -299,74 +206,8 @@ $.extend(ElementNode.prototype, {
         return toret;
     },
 
-    append: INSERTION(function(nativeNode) {
-        this._$.append(nativeNode);
-    }),
-
-    prepend: INSERTION(function(nativeNode) {
-        this._$.prepend(nativeNode);
-    }),
-
-    insertAtIndex: function(nativeNode, index) {
-        var contents = this.contents();
-        if(index < contents.length) {
-            return contents[index].before(nativeNode);
-        } else if(index === contents.length) {
-            return this.append(nativeNode);
-        }
-    },
-
-    unwrapContent: function() {
-        var parent = this.parent();
-        if(!parent) {
-            return;
-        }
-
-        var myContents = this.contents(),
-            myIdx = parent.indexOf(this);
-
-
-        if(myContents.length === 0) {
-            return this.detach();
-        }
-
-        var prev = this.prev(),
-            next = this.next(),
-            moveLeftRange, moveRightRange, leftMerged;
-
-        if(prev && (prev.nodeType === TEXT_NODE) && (myContents[0].nodeType === TEXT_NODE)) {
-            prev.appendText(myContents[0].getText());
-            myContents[0].detach();
-            moveLeftRange = true;
-            leftMerged = true;
-        } else {
-            leftMerged = false;
-        }
-
-        if(!(leftMerged && myContents.length === 1)) {
-            var lastContents = _.last(myContents);
-            if(next && (next.nodeType === TEXT_NODE) && (lastContents.nodeType === TEXT_NODE)) {
-                next.prependText(lastContents.getText());
-                lastContents.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() {
@@ -380,62 +221,6 @@ $.extend(ElementNode.prototype, {
     }
 });
 
-// trans
-
-// todo - split+append
-
-// ElementNode.prototype.transformations.register(transformations.createContextTransformation({
-//     name: 'smartxml.setAttr',
-//     impl: function(args) {
-//         this.setAttr(args.name, args.value);
-//     },
-//     getChangeRoot: function() {
-//         return this.context;
-//     }
-// }));
-
-// ElementNode.prototype.transformations.register(transformations.createContextTransformation({
-//     name: 'smartxml.setAttr2',
-//     impl: function(args) {
-//         this.prevAttr = this.getAttr(args.name);
-//         this.setAttr(args.name, args.value);
-//     },
-//     undo: function(args) {
-//         this.setAttr(args.name, this.prevAttr);
-//     }
-// }));
-
-// DocumentNode.prototype.transformations.register(transformations.createContextTransformation({
-//     name: 'smartxml.wrapWith',
-//     getChangeRoot: function() {
-//         return this.context.parent();
-//     },
-//     impl: function(args) {
-//         return this.wrapWith(args);
-//     }
-// }));
-
-// DocumentNode.prototype.transformations.register(transformations.createContextTransformation({
-//     name: 'smartxml.wrapText',
-//     getChangeRoot: function() {
-//         return this.context;
-//     },
-//     impl: function(args) {
-//         return this.wrapText(args);
-//     }
-// }));
-
-// DocumentNode.prototype.transformations.register(transformations.createContextTransformation({
-//     name: 'smartxml.detach',
-//     getChangeRoot: function() {
-//         return this.context.parent();
-//     },
-//     impl: function(args) {
-//         return this.detach();
-//     }
-// }));
-
-///
 
 var TextNode = function(nativeNode, document) {
     DocumentNode.call(this, nativeNode, document);
@@ -449,74 +234,6 @@ $.extend(TextNode.prototype, {
         return this.nativeNode.data;
     },
 
-    setText: function(text) {
-        //console.log('smartxml: ' + 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: {tagName: desc.tagName, attrs: desc.attrs}
-            });
-        } else {
-            return DocumentNode.prototype.wrapWith.call(this, desc);
-        }
-    },
-
-    split: function(params) {
-        var parentElement = this.parent(),
-            passed = false,
-            succeedingChildren = [],
-            prefix = this.getText().substr(0, params.offset),
-            suffix = this.getText().substr(params.offset);
-
-        parentElement.contents().forEach(function(child) {
-            if(passed) {
-                succeedingChildren.push(child);
-            }
-            if(child.sameNode(this)) {
-                passed = true;
-            }
-        }.bind(this));
-
-        if(prefix.length > 0) {
-            this.setText(prefix);
-        }
-        else {
-            this.detach();
-        }
-
-        var attrs = {};
-        parentElement.getAttrs().forEach(function(attr) {attrs[attr.name] = attr.value; });
-        var newElement = this.document.createDocumentNode({tagName: parentElement.getTagName(), attrs: attrs});
-        parentElement.after(newElement);
-
-        if(suffix.length > 0) {
-            newElement.append({text: suffix});
-        }
-        succeedingChildren.forEach(function(child) {
-            newElement.append(child);
-        });
-
-        return {first: parentElement, second: newElement};
-    },
-
     triggerTextChangeEvent: function() {
         var event = new events.ChangeEvent('nodeTextChange', {node: this});
         this.document.trigger('change', event);
@@ -524,66 +241,54 @@ $.extend(TextNode.prototype, {
 });
 
 
-// TextNode.prototype.transformations.register(transformations.createContextTransformation({
-//     name: 'rng.breakContent',
-//     // impl: function(args) {
-//     //     var node = this.context,
-//     //         newNodes, emptyNode, emptyText;
-//     //     newNodes = node.transform('smartxml.split', {offset: args.offset});
-//     //     [newNodes.first, newNodes.second].some(function(newNode) {
-//     //         if(!(newNode.contents().length)) {
-//     //             newNode.transform('smartxml.append', {text: ''});
-//     //             return true; // break
-//     //         }
-//     //     });
-//     //     return _.extend(newNodes, {emptyText: emptyText});
-//     // },
-//     impl: function(args) {
-//         var node = this,
-//             newNodes, emptyNode, emptyText;
-//         newNodes = node.split({offset: args.offset});
-//         [newNodes.first, newNodes.second].some(function(newNode) {
-//             if(!(newNode.contents().length)) {
-//                 newNode.append({text: ''});
-//                 return true; // break
-//             }
-//         });
-//         return _.extend(newNodes, {emptyText: emptyText});
-//     },
-//     getChangeRoot: function() {
-//         return this.context.parent().parent();
-//     },
-//     isAllowed: function(args) {
-//         var parent = this.parent();
-//         return !!(parent && parent.parent());
-//     }
-// }));
-
-
-// ElementNode.prototype.transformations.register(transformations.createContextTransformation({
-//     name: 'smartxml.setText',
-//     impl: function(args) {
-//         this.setText(args.text);
-//     },
-//     getChangeRoot: function() {
-//         return this.context;
-//     }
-// }));
+var parseXML = function(xml) {
+    var toret = $($.trim(xml));
+    if(!toret.length) {
+        throw new Error('Unable to parse XML: ' + xml);
+    }
+    return toret[0];
 
+};
 
-var parseXML = function(xml) {
-    return $($.trim(xml))[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) {
-    this.loadXML(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.transformations = new transformations.TransformationStorage();
     
     this._nodeMethods = {};
-    this._nodeTransformations = new transformations.TransformationStorage();
+    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);
 };
 
 $.extend(Document.prototype, Backbone.Events, {
@@ -592,81 +297,71 @@ $.extend(Document.prototype, Backbone.Events, {
 
     createDocumentNode: function(from) {
         if(!(from instanceof Node)) {
-            if(from.text !== undefined) {
-                /* globals document */
-                from = document.createTextNode(from.text);
+            if(typeof from === 'string') {
+                from = parseXML(from);
+                this.normalizeXML(from);
             } else {
-                var node = $('<' + from.tagName + '>');
-
-                _.keys(from.attrs || {}).forEach(function(key) {
-                    node.attr(key, from.attrs[key]);
-                });
+                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];
+                    from = node[0];
+                }
             }
         }
-        var Factory;
+        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);
-        toret.transformations = this._nodeTransformations;
+        _.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);
+        });
+
         return toret;
     },
 
     loadXML: function(xml, options) {
         options = options || {};
-        defineDocumentProperties(this, $(parseXML(xml)));
+        this._defineDocumentProperties($(parseXML(xml)));
+        this.normalizeXML(this.dom);
         if(!options.silent) {
             this.trigger('contentSet');
         }
     },
 
+    normalizeXML: function(nativeNode) {
+        void(nativeNode); // noop
+    },
+
     toXML: function() {
         return this.root.toXML();
     },
 
     containsNode: function(node) {
-        return this.root && (node.nativeNode === this.root.nativeNode || node._$.parents().index(this.root._$) !== -1);
-    },
-
-    wrapNodes: function(params) {
-        if(!(params.node1.parent().sameNode(params.node2.parent()))) {
-            throw new Error('Wrapping non-sibling nodes not supported.');
-        }
-
-        var parent = params.node1.parent(),
-            parentContents = parent.contents(),
-            wrapper = this.createDocumentNode({
-                tagName: params._with.tagName,
-                attrs: params._with.attrs}),
-            idx1 = parent.indexOf(params.node1),
-            idx2 = parent.indexOf(params.node2);
-
-        if(idx1 > idx2) {
-            var tmp = idx1;
-            idx1 = idx2;
-            idx2 = tmp;
-        }
-
-        var insertingMethod, insertingTarget;
-        if(idx1 === 0) {
-            insertingMethod = 'prepend';
-            insertingTarget = parent;
-        } else {
-            insertingMethod = 'after';
-            insertingTarget = parentContents[idx1-1];
-        }
-
-        for(var i = idx1; i <= idx2; i++) {
-            wrapper.append(parentContents[i].detach());
-        }
-
-        insertingTarget[insertingMethod](wrapper);
-        return wrapper;
+        return this.root && this.root.containsNode(node);
     },
 
     getSiblingParents: function(params) {
@@ -678,68 +373,21 @@ $.extend(Document.prototype, Backbone.Events, {
             return noSiblingParents;
         }
 
-        var i;
-        for(i = 0; i < Math.min(parents1.length, parents2.length); i++) {
+        var stop = Math.min(parents1.length, parents2.length),
+            i;
+        for(i = 0; i < stop; i++) {
             if(parents1[i].sameNode(parents2[i])) {
                 continue;
             }
             break;
         }
-        return {node1: parents1[i], node2: parents2[i]};
-    },
-
-    _wrapText: function(params) {
-        params = _.extend({textNodeIdx: 0}, params);
-        if(typeof params.textNodeIdx === 'number') {
-            params.textNodeIdx = [params.textNodeIdx];
+        if(i === stop) {
+            i--;
         }
-        
-        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 wrapperElement = this.createDocumentNode({tagName: params._with.tagName, attrs: params._with.attrs});
-        textNode1.after(wrapperElement);
-        textNode1.detach();
-        
-        if(prefixOutside.length > 0) {
-            wrapperElement.before({text:prefixOutside});
-        }
-        if(sameNode) {
-            var core = textNode1.getText().substr(params.offsetStart, params.offsetEnd - params.offsetStart);
-            wrapperElement.append({text: core});
-        } else {
-            textNode2.detach();
-            if(prefixInside.length > 0) {
-                wrapperElement.append({text: prefixInside});
-            }
-            for(var i = idx1 + 1; i < idx2; i++) {
-                wrapperElement.append(contentsInside[i]);
-            }
-            if(suffixInside.length > 0) {
-                wrapperElement.append({text: suffixInside});
-            }
-        }
-        if(suffixOutside.length > 0) {
-            wrapperElement.after({text: suffixOutside});
-        }
-        return wrapperElement;
+        return {node1: parents1[i], node2: parents2[i]};
     },
 
     trigger: function() {
-        //console.log('trigger: ' + arguments[0] + (arguments[1] ? ', ' + arguments[1].type : ''));
         Backbone.Events.trigger.apply(this, arguments);
     },
 
@@ -755,130 +403,184 @@ $.extend(Document.prototype, Backbone.Events, {
         return insertion;
     },
 
-    replaceRoot: function(node) {
-        var insertion = this.getNodeInsertion(node);
-        this.root.detach();
-        defineDocumentProperties(this, insertion.ofNode._$);
-        insertion.ofNode.triggerChangeEvent('nodeAdded');
-        return insertion.ofNode;
-    },
-
-    registerMethod: function(methodName, method) {
-        this[methodName] = method;
-    },
-
-    registerTransformation: function(Transformation) {
-        return this.transformations.register(Transformation);
+    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);
     },
 
-    registerNodeMethod: function(methodName, method) {
-        this._nodeMethods[methodName] = method;
-    },
-
-    registerNodeTransformation: function(Transformation) {
-        this._nodeTransformations.register(Transformation);
+    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) {
-        //debugger;
-        var doc = this,
-            existingPropertyNames = _.values(this);
+        var doc = this;
 
-        var getTrans = function(desc, methodName) {
-            if(typeof desc === 'function') {
-                desc = {impl: desc};
-            }
-            if(!desc.impl) {
-                throw new Error('Got transformation description without implementation.')
-            }
-            desc.name = desc.name || methodName;
-            return desc;
-        };
-
-        [
-            {source: extension.document, target: doc},
-            {source: extension.documentNode, target: [doc.ElementNodeFactory.prototype, doc.TextNodeFactory.prototype]},
-
-        ].forEach(function(mapping) {
-            if(mapping.source) {
-                if(mapping.source.methods) {
-                    existingPropertyNames = _.values(mapping.target)
-                    _.pairs(mapping.source.methods).forEach(function(pair) {
+        ['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],
-                            targets = _.isArray(mapping.target) ? mapping.target : [mapping.target];
-                        if(_.contains(existingPropertyNames, methodName)) {
-                            throw new Error('Cannot extend {target} with method name {methodName}. Name already exists.'
-                                .replace('{target}', mapping.target)
-                                .replace('{methodName}', methodName)
-                            );
-                        }
-                        targets.forEach(function(target) {
-                            if(target === doc) {
-                                target.registerMethod(methodName, method);
-                            } else {
-                                doc.registerNodeMethod(methodName, method);
-                            }
-
-                        });
+                            method = pair[1];
+
+                        doc.registerMethod(methodName, method, dstName);
+
                     });
                 }
 
-                if(mapping.source.transformations) {
-                    _.pairs(mapping.source.transformations).forEach(function(pair) {
-                        var transformation = getTrans(pair[1], pair[0]),
-                            targets = _.isArray(mapping.target) ? mapping.target : [mapping.target];
-                        targets.forEach(function(target) {
-                            if(target === doc) {
-                                target.registerTransformation(transformations.createContextTransformation(transformation));    
-                            } else {
-                                doc.registerNodeTransformation(transformations.createContextTransformation(transformation));
-                            }
-
-                            
-                        });
+                if(dstExtension.transformations) {
+                    _.pairs(dstExtension.transformations).forEach(function(pair) {
+                        var name = pair[0],
+                            desc = pair[1];
+                        doc.registerTransformation(desc, name, dstName);
                     });
                 }
             }
         });
     },
 
-    transform: function(transformation, args) {
-        //console.log('transform');
-        var Transformation, toret;
-        if(typeof transformation === 'string') {
-            Transformation = this.transformations.get(transformation);
-            if(Transformation) {
-                transformation = new Transformation(this, this, args);
+    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);
+            }
+        } else {
+            if(documentUnchangedHandler) {
+                documentUnchangedHandler.call(context);
             }
-        } 
+        }
+    },
+
+    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++;
-            toret = transformation.run();
-            if(this._transformationLevel === 1) {
-                this.undoStack.push(transformation);
-            }
+            
+            this.ifChanged(
+                this,
+                function() {
+                    toret = transformation.run({beUndoable:this._transformationLevel === 1});
+                },
+                function() {
+                    if(this._transformationLevel === 1 && !this._undoInProgress) {
+                        this._currentTransaction.pushTransformation(transformation);
+                    }
+                    if(!this._undoInProgress && this._transformationLevel === 1) {
+                        this.redoStack = [];
+                    }
+                }
+            );
+
             this._transformationLevel--;
-            //console.log('clearing redo stack');
-            this.redoStack = [];
             return toret;
         } else {
             throw new Error('Transformation ' + transformation + ' doesn\'t exist!');
         }
     },
     undo: function() {
-        var transformation = this.undoStack.pop();
-        if(transformation) {
-            transformation.undo();
-            this.redoStack.push(transformation);
+        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 transformation = this.redoStack.pop();
-        if(transformation) {
-            transformation.run();
-            this.undoStack.push(transformation);
+        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._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;
+    },
+
+    transaction: function(callback, context, metadata) {
+        var toret;
+        this.startTransaction(metadata);
+        toret = callback.call(context);
+        this.endTransaction();
+        return toret;
     },
 
     getNodeByPath: function(path) {
@@ -887,36 +589,43 @@ $.extend(Document.prototype, Backbone.Events, {
             toret = toret.contents()[idx];
         });
         return toret;
+    },
+
+    _defineDocumentProperties: function($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, $document) {
-    Object.defineProperty(doc, 'root', {get: function() {
-        return doc.createDocumentNode($document[0]);
-    }, configurable: true});
-    Object.defineProperty(doc, 'dom', {get: function() {
-        return $document[0];
-    }, configurable: true});
+var Transaction = function(transformations, metadata) {
+    this.transformations = transformations || [];
+    this.metadata = metadata;
 };
-
-// Document.prototype.transformations.register(transformations.createContextTransformation({
-//     name: 'smartxml.wrapNodes',
-//     // init: function() {
-
-//     // },
-//     // getChangeRoot: function() {
-//     //     return this.context;
-//     // },
-//     impl: function(args) {
-//         this.wrapNodes(args);
-//     },
-
-// }));
+$.extend(Transaction.prototype, {
+    pushTransformation: function(transformation) {
+        this.transformations.push(transformation);
+    },
+    hasTransformations: function() {
+        return this.transformations.length > 0;
+    }
+});
 
 
 return {
     documentFromXML: function(xml) {
-        return new Document(xml);
+        var doc = new Document(xml);
+        return doc;
     },
 
     elementNodeFromXML: function(xml) {