Change#getModel(), Doc cleanup, Conflict event

lib/models/change.js

@@ -66,6 +66,7 @@ Change.Conflict = Conflict;
  */
 
 Change.setup = function() {
+  DataModel.setup.call(this);
   var Change = this;
 
   Change.getter.id = function() {
@@ -271,7 +272,9 @@ Change.prototype.getModelCtor = function() {
 
 Change.prototype.equals = function(change) {
   if(!change) return false;
-  return change.rev === this.rev;
+  var thisRev = this.rev || null;
+  var thatRev = change.rev || null;
+  return thisRev === thatRev;
 }
 
 /**
@@ -402,56 +405,169 @@ Change.handleError = function(err) {
 
 Change.prototype.getModelId = function() {
   // TODO(ritch) get rid of the need to create an instance
-  var Model = this.constructor.settings.model;
+  var Model = this.constructor.settings.trackModel;
   var id = this.modelId;
   var m = new Model();
   m.setId(id);
   return m.getId();
 }
 
+Change.prototype.getModel = function(callback) {
+  var Model = this.constructor.settings.trackModel;
+  var id = this.getModelId();
+  Model.findById(id, callback);
+}
+
 /**
  * When two changes conflict a conflict is created.
  *
  * **Note: call `conflict.fetch()` to get the `target` and `source` models.
  * 
- * @param {Change} sourceChange The change object for the source model
+ * @param {*} sourceModelId
- * @param {Change} targetChange The conflicting model's change object
+ * @param {*} targetModelId
- * @property {Model} source The source model instance
+ * @property {ModelClass} source The source model instance
- * @property {Model} target The target model instance
+ * @property {ModelClass} target The target model instance
  */
 
-function Conflict(sourceChange, targetChange) {
+function Conflict(modelId, SourceModel, TargetModel) {
-  this.sourceChange = sourceChange;
+  this.SourceModel = SourceModel;
-  this.targetChange = targetChange;
+  this.TargetModel = TargetModel;
+  this.SourceChange = SourceModel.getChangeModel();
+  this.TargetChange = TargetModel.getChangeModel();
+  this.modelId = modelId;
 }
 
-Conflict.prototype.fetch = function(cb) {
+/**
+ * Fetch the conflicting models.
+ *
+ * @callback {Function} callback
+ * @param {Error}
+ * @param {DataModel} source
+ * @param {DataModel} target
+ */
+
+Conflict.prototype.models = function(cb) {
   var conflict = this;
-  var tasks = [
+  var SourceModel = this.SourceModel;
+  var TargetModel = this.TargetModel;
+  var source;
+  var target;
+
+  async.parallel([
     getSourceModel,
     getTargetModel
-  ];
+  ], done);
 
-  async.parallel(tasks, cb);
+  function getSourceModel(cb) {
-
+    SourceModel.findById(conflict.modelId, function(err, model) {
-  function getSourceModel(change, cb) {
-    conflict.sourceModel.getModel(function(err, model) {
       if(err) return cb(err);
-      conflict.source = model;
+      source = model;
       cb();
     });
   }
 
   function getTargetModel(cb) {
-    conflict.targetModel.getModel(function(err, model) {
+    TargetModel.findById(conflict.modelId, function(err, model) {
       if(err) return cb(err);
-      conflict.target = model;
+      target = model;
       cb();
     });
   }
+
+  function done(err) {
+    if(err) return cb(err);
+    cb(null, source, target);
+  }
 }
 
-Conflict.prototype.resolve = function(cb) {
+/**
-  this.sourceChange.prev = this.targetChange.rev;
+ * Get the conflicting changes.
-  this.sourceChange.save(cb);
+ *
+ * @callback {Function} callback
+ * @param {Error} err
+ * @param {Change} sourceChange
+ * @param {Change} targetChange
+ */
+
+Conflict.prototype.changes = function(cb) {
+  var conflict = this;
+  var sourceChange;
+  var targetChange;
+
+  async.parallel([
+    getSourceChange,
+    getTargetChange
+  ], done);
+
+  function getSourceChange(cb) {
+    conflict.SourceChange.findOne({
+      modelId: conflict.sourceModelId
+    }, function(err, change) {
+      if(err) return cb(err);
+      sourceChange = change;
+      cb();
+    });
+  }
+
+  function getTargetChange(cb) {
+    debugger;
+    conflict.TargetChange.findOne({
+      modelId: conflict.targetModelId
+    }, function(err, change) {
+      if(err) return cb(err);
+      targetChange = change;
+      cb();
+    });
+  }
+
+  function done(err) {
+    if(err) return cb(err);
+    cb(null, sourceChange, targetChange);
+  }
+}
+
+/**
+ * Resolve the conflict.
+ *
+ * @callback {Function} callback
+ * @param {Error} err
+ */
+
+Conflict.prototype.resolve = function(cb) {
+  var conflict = this;
+  conflict.changes(function(err, sourceChange, targetChange) {
+    if(err) return callback(err);
+    sourceChange.prev = targetChange.rev;
+    sourceChange.save(cb);
+  });
+}
+
+/**
+ * Determine the conflict type. 
+ * 
+ * ```js
+ * // possible results are
+ * Change.UPDATE // => source and target models were updated
+ * Change.DELETE // => the source and or target model was deleted
+ * Change.UNKNOWN // => the conflict type is uknown or due to an error
+ * ```
+ * @callback {Function} callback
+ * @param {Error} err
+ * @param {String} type The conflict type.
+ */
+
+Conflict.prototype.type = function(cb) {
+  var conflict = this;
+  this.changes(function(err, sourceChange, targetChange) {
+    if(err) return cb(err);
+    var sourceChangeType = sourceChange.type();
+    var targetChangeType = targetChange.type();
+    if(sourceChangeType === Change.UPDATE && targetChangeType === Change.UPDATE) {
+      return cb(null, Change.UPDATE);
+    }
+    if(sourceChangeType === Change.DELETE || targetChangeType === Change.DELETE) {
+      return cb(null, Change.DELETE);
+    }
+    return cb(null, Change.UNKNOWN);
+  });
 }

lib/models/data-model.js

@@ -44,7 +44,6 @@ DataModel.setup = function setupDataModel() {
     return val ? new DataModel(val) : val;
   });
 
-
   // enable change tracking (usually for replication)
   if(this.settings.trackChanges) {
     DataModel._defineChangeModel();
@@ -424,6 +423,8 @@ DataModel.setupRemoting = function() {
   var typeName = DataModel.modelName;
   var options = DataModel.settings;
 
+  // TODO(ritch) setRemoting should create its own function...
+
   setRemoting(DataModel.create, {
     description: 'Create a new instance of the model and persist it into the data source',
     accepts: {arg: 'data', type: 'object', description: 'Model instance data', http: {source: 'body'}},
@@ -592,6 +593,11 @@ DataModel.changes = function(since, filter, callback) {
     callback = since;
     since = -1;
   }
+  if(typeof filter === 'function') {
+    callback = filter;
+    since = -1;
+    filter = {};
+  }
 
   var idName = this.dataSource.idName(this.modelName);
   var Change = this.getChangeModel();
@@ -699,28 +705,16 @@ DataModel.replicate = function(since, targetModel, options, callback) {
   }
 
   var tasks = [
-    getLocalChanges,
+    getSourceChanges,
     getDiffFromTarget,
     createSourceUpdates,
     bulkUpdate,
     checkpoint
   ];
 
-  async.waterfall(tasks, function(err) {
+  async.waterfall(tasks, done);
-    if(err) return callback(err);
-    var conflicts = diff.conflicts.map(function(change) {
-      var sourceChange = new Change({
-        modelName: sourceModel.modelName,
-        modelId: change.modelId
-      });
-      var targetChange = new TargetChange(change);
-      return new Change.Conflict(sourceChange, targetChange);
-    });
 
-    callback && callback(null, conflicts);
+  function getSourceChanges(cb) {
-  });
-
-  function getLocalChanges(cb) {
     sourceModel.changes(since, options.filter, cb);
   }
 
@@ -735,7 +729,7 @@ DataModel.replicate = function(since, targetModel, options, callback) {
       sourceModel.createUpdates(diff.deltas, cb);
     } else {
       // nothing to replicate
-      callback(null, []);
+      done();
     }
   }
 
@@ -747,6 +741,22 @@ DataModel.replicate = function(since, targetModel, options, callback) {
     var cb = arguments[arguments.length - 1];
     sourceModel.checkpoint(cb);
   }
+
+  function done(err) {
+    if(err) return callback(err);
+
+    var conflicts = diff.conflicts.map(function(change) {
+      return new Change.Conflict(
+        change.modelId, sourceModel, targetModel
+      );
+    });
+
+    if(conflicts.length) {
+      sourceModel.emit('conflicts', conflicts);
+    }
+
+    callback && callback(null, conflicts);
+  }
 }
 
 /**
@@ -924,7 +934,7 @@ DataModel._defineChangeModel = function() {
   return this.Change = BaseChangeModel.extend(this.modelName + '-change',
     {},
     {
-      model: this
+      trackModel: this
     }
   );
 }