Add 'forEachNode' function

lib/index.js

@@ -23,8 +23,7 @@ JSONPath.prototype.parent = function(obj, string) {
   assert.ok(string, "we need a path");
 
   var node = this.nodes(obj, string)[0];
-  var key = node.path.pop(); /* jshint unused:false */
-  return this.value(obj, node.path);
+  return _get_value_by_path(obj, node.path, 1);
 }
 
 JSONPath.prototype.apply = function(obj, string, fn) {
@@ -33,19 +32,37 @@ JSONPath.prototype.apply = function(obj, string, fn) {
   assert.ok(string, "we need a path");
   assert.equal(typeof fn, "function", "fn needs to be function")
 
-  var nodes = this.nodes(obj, string).sort(function(a, b) {
+  return this._iterateNodes(obj, string, function(node) {
+    var key = node.path[node.path.length - 1];
+    var parent = _get_value_by_path(obj, node.path, 1);
+    var val = node.value = fn.call(obj, parent[key]);
+    parent[key] = val;
+  });
+}
+
+JSONPath.prototype.forEachNode = function(obj, path, fn) {
+
+  assert.ok(obj instanceof Object, "obj needs to be an object");
+  assert.ok(path, "we need a path");
+  assert.equal(typeof fn, "function", "fn needs to be function")
+
+  return this._iterateNodes(obj, path, function(node) {
+    fn(new _NodeWrapper(obj, node.path, node.value));
+  });
+}
+
+JSONPath.prototype._iterateNodes = function(obj, path, fn) {
+
+  assert.ok(obj instanceof Object, "obj needs to be an object");
+  assert.ok(path, "we need a path");
+  assert.equal(typeof fn, "function", "fn needs to be function")
+
+  var nodes = this.nodes(obj, path).sort(function(a, b) {
     // sort nodes so we apply from the bottom up
     return b.path.length - a.path.length;
   });
 
-  nodes.forEach(function(node) {
-    var key = node.path.pop();
-    var parent = this.value(obj, this.stringify(node.path));
-    var val = node.value = fn.call(obj, parent[key]);
-    parent[key] = val;
-  }, this);
-
-  return nodes;
+  return nodes.forEach(fn.bind(this));
 }
 
 JSONPath.prototype.value = function(obj, path, value) {
@@ -57,7 +74,7 @@ JSONPath.prototype.value = function(obj, path, value) {
     var node = this.nodes(obj, path).shift();
     if (!node) return this._vivify(obj, path, value);
     var key = node.path.slice(-1).shift();
-    var parent = this.parent(obj, this.stringify(node.path));
+    var parent = _get_value_by_path(obj, node.path, 1);
     parent[key] = value;
   }
   return this.query(obj, this.stringify(path), 1).shift();
@@ -240,6 +257,49 @@ function _is_string(obj) {
   return Object.prototype.toString.call(obj) == '[object String]';
 }
 
+function _get_value_by_path(obj, path, skip) {
+  skip = skip || 0;
+  for (var i = 1; i < path.length - skip; ++i)
+    obj = obj[path[i]];
+  return obj;
+}
+
+var _NodeWrapper = function(root, path, value) {
+  this.root = root;
+  this.path = path;
+  this.value = value;
+};
+
+_NodeWrapper.prototype.parent = function(skip) {
+  skip = skip + 1 || 1;
+  if (skip > this.path.length)
+    throw Error("couldn't skip passed root object");
+  var parentPath = this.path.slice(0, -skip);
+  var parentValue = _get_value_by_path(this.root, parentPath);
+  return new _NodeWrapper(this.root, parentPath, parentValue);
+};
+
+_NodeWrapper.prototype.key = function() {
+  return this.path[this.path.length - 1];
+};
+
+_NodeWrapper.prototype.update = function(value) {
+  this.parent()[this.key()] = value;
+};
+
+_NodeWrapper.prototype.remove = function() {
+  var parent = this.parent();
+  var key = this.key();
+  var value = parent[key];
+
+  if (Array.isArray(parent))
+    Array.prototype.splice.call(parent, key, 1);
+  else
+    delete parent[key];
+
+  return value;
+};
+
 JSONPath.Handlers = Handlers;
 JSONPath.Parser = Parser;