Tree Transformer Async

Transform nodes in the tree asynchronously and sequentially.

Asynchronous version of Tree Transformer. Actions can return a promise and .visit() returns a promise.

Example

var fs = require('fs');
var Q = require('q');
var TransformerAsync = require('tree-transformer-async');
var nodes = [
    { type: 'import', value: 'path/to/file1' },
    { type: 'import', value: 'path/to/file2' },
];
 
function MyVisitorAsync() {}
MyVisitorAsync.prototype = new VisitorAsync();
 
MyVisitorAsync.prototype.visit_import = function (importNode) {
    var deferred = Q.defer();
    fs.readFile(importNode.value, 'utf8', deferred.makeNodeResolver());
    return deferred.promise.then(function (content) {
        return content;
    });
};
 
new MyVisitorAsync().visit(nodes).then(function (result) {
    console.log(result); // [content of file1, content of file2]
});