var traverse = module.exports = function (obj) { return new Traverse(obj); }; function Traverse (obj) { this.value = obj; } Traverse.prototype.get = function (ps) { var node = this.value; for (var i = 0; i < ps.length; i ++) { var key = ps[i]; if (!node || !hasOwnProperty.call(node, key)) { node = undefined; break; } node = node[key]; } return node; }; Traverse.prototype.has = function (ps) { var node = this.value; for (var i = 0; i < ps.length; i ++) { var key = ps[i]; if (!node || !hasOwnProperty.call(node, key)) { return false; } node = node[key]; } return true; }; Traverse.prototype.set = function (ps, value) { var node = this.value; for (var i = 0; i < ps.length - 1; i ++) { var key = ps[i]; if (!hasOwnProperty.call(node, key)) node[key] = {}; node = node[key]; } node[ps[i]] = value; return value; }; Traverse.prototype.map = function (cb) { return walk(this.value, cb, true); }; Traverse.prototype.forEach = function (cb) { this.value = walk(this.value, cb, false); return this.value; }; Traverse.prototype.reduce = function (cb, init) { var skip = arguments.length === 1; var acc = skip ? this.value : init; this.forEach(function (x) { if (!this.isRoot || !skip) { acc = cb.call(this, acc, x); } }); return acc; }; Traverse.prototype.paths = function () { var acc = []; this.forEach(function (x) { acc.push(this.path); }); return acc; }; Traverse.prototype.nodes = function () { var acc = []; this.forEach(function (x) { acc.push(this.node); }); return acc; }; Traverse.prototype.clone = function () { var parents = [], nodes = []; return (function clone (src) { for (var i = 0; i < parents.length; i++) { if (parents[i] === src) { return nodes[i]; } } if (typeof src === 'object' && src !== null) { var dst = copy(src); parents.push(src); nodes.push(dst); forEach(objectKeys(src), function (key) { dst[key] = clone(src[key]); }); parents.pop(); nodes.pop(); return dst; } else { return src; } })(this.value); }; function walk (root, cb, immutable) { var path = []; var parents = []; var alive = true; return (function walker (node_) { var node = immutable ? copy(node_) : node_; var modifiers = {}; var keepGoing = true; var state = { node : node, node_ : node_, path : [].concat(path), parent : parents[parents.length - 1], parents : parents, key : path.slice(-1)[0], isRoot : path.length === 0, level : path.length, circular : null, update : function (x, stopHere) { if (!state.isRoot) { state.parent.node[state.key] = x; } state.node = x; if (stopHere) keepGoing = false; }, 'delete' : function (stopHere) { delete state.parent.node[state.key]; if (stopHere) keepGoing = false; }, remove : function (stopHere) { if (isArray(state.parent.node)) { state.parent.node.splice(state.key, 1); } else { delete state.parent.node[state.key]; } if (stopHere) keepGoing = false; }, keys : null, before : function (f) { modifiers.before = f }, after : function (f) { modifiers.after = f }, pre : function (f) { modifiers.pre = f }, post : function (f) { modifiers.post = f }, stop : function () { alive = false }, block : function () { keepGoing = false } }; if (!alive) return state; function updateState() { if (typeof state.node === 'object' && state.node !== null) { if (!state.keys || state.node_ !== state.node) { state.keys = objectKeys(state.node) } state.isLeaf = state.keys.length == 0; for (var i = 0; i < parents.length; i++) { if (parents[i].node_ === node_) { state.circular = parents[i]; break; } } } else { state.isLeaf = true; state.keys = null; } state.notLeaf = !state.isLeaf; state.notRoot = !state.isRoot; } updateState(); // use return values to update if defined var ret = cb.call(state, state.node); if (ret !== undefined && state.update) state.update(ret); if (modifiers.before) modifiers.before.call(state, state.node); if (!keepGoing) return state; if (typeof state.node == 'object' && state.node !== null && !state.circular) { parents.push(state); updateState(); forEach(state.keys, function (key, i) { path.push(key); if (modifiers.pre) modifiers.pre.call(state, state.node[key], key); var child = walker(state.node[key]); if (immutable && hasOwnProperty.call(state.node, key)) { state.node[key] = child.node; } child.isLast = i == state.keys.length - 1; child.isFirst = i == 0; if (modifiers.post) modifiers.post.call(state, child); path.pop(); }); parents.pop(); } if (modifiers.after) modifiers.after.call(state, state.node); return state; })(root).node; } function copy (src) { if (typeof src === 'object' && src !== null) { var dst; if (isArray(src)) { dst = []; } else if (isDate(src)) { dst = new Date(src.getTime ? src.getTime() : src); } else if (isRegExp(src)) { dst = new RegExp(src); } else if (isError(src)) { dst = { message: src.message }; } else if (isBoolean(src)) { dst = new Boolean(src); } else if (isNumber(src)) { dst = new Number(src); } else if (isString(src)) { dst = new String(src); } else if (Object.create && Object.getPrototypeOf) { dst = Object.create(Object.getPrototypeOf(src)); } else if (src.constructor === Object) { dst = {}; } else { var proto = (src.constructor && src.constructor.prototype) || src.__proto__ || {} ; var T = function () {}; T.prototype = proto; dst = new T; } forEach(objectKeys(src), function (key) { dst[key] = src[key]; }); return dst; } else return src; } var objectKeys = Object.keys || function keys (obj) { var res = []; for (var key in obj) res.push(key) return res; }; function toS (obj) { return Object.prototype.toString.call(obj) } function isDate (obj) { return toS(obj) === '[object Date]' } function isRegExp (obj) { return toS(obj) === '[object RegExp]' } function isError (obj) { return toS(obj) === '[object Error]' } function isBoolean (obj) { return toS(obj) === '[object Boolean]' } function isNumber (obj) { return toS(obj) === '[object Number]' } function isString (obj) { return toS(obj) === '[object String]' } var isArray = Array.isArray || function isArray (xs) { return Object.prototype.toString.call(xs) === '[object Array]'; }; var forEach = function (xs, fn) { if (xs.forEach) return xs.forEach(fn) else for (var i = 0; i < xs.length; i++) { fn(xs[i], i, xs); } }; forEach(objectKeys(Traverse.prototype), function (key) { traverse[key] = function (obj) { var args = [].slice.call(arguments, 1); var t = new Traverse(obj); return t[key].apply(t, args); }; }); var hasOwnProperty = Object.hasOwnProperty || function (obj, key) { return key in obj; };