What is "traverse-async"?

traverse-async is a Javascript/node.js module that asynchronously and recursively walks an object tree.

Usage

    var traverse = require('traverse-async').traverse;

    traverse(object, function(node, next){
        console.log("Current node", node);
        console.log("Context object", this);
        next();
    }, function(newObj) {
        console.log("Done!");
    });

The queue object

traverse-async returns an object on each traverse that allows you to perform functions on the current queue.

break

Kill the whole queue when necessary.

    var queue = traverse(object, function(node, next){

        if (something) { queue.break() }

    });

push

Add a node to the current queue.

Context

The callback has a context (its this object) with these attributes:

this.key

The name of the key of the present node in its parent. This is undefined for the root node.

this.parent

The parent of the current node. This is undefined for the root node.

this.parent can be useful when deleting the current node:

    delete this.parent[this.key]

this.path

An array of string keys from the root to the present node

Examples

Walk an object tree, resolving promises at arbitrary, nested locations:

    var traverse = require('traverse-async').traverse;

    var promises = {};

    traverse.traverse(result, function(value, next) {
      var key, parent, path;
      if (isPromise(this.node)) {
        parent = this.parent;
        key = this.key;
        path = this.path.join(".");
        promises[path] = this.node.then(function(value) {
          parent[key] = value;
          delete promises[path];
          if (Object.keys(promises).length === 0) {

            // All promises have been fulfilled

          }
        }, function(err) {

            // One of the promises errored

        });
      }
      return next();
    }, function() {
      if (Object.keys(promises).length === 0) {

        // No promises were found or they are already fulfilled.

      }
    });

Installation

Use npm.

$ npm install traverse-async

Otherwise, you can check traverse-async into your repository and expose it:

$ git clone git://github.com/awnist/js-traverse-async.git node_modules/traverse-async/

traverse-async is UNLICENSED.