Node.js: What techniques are there for writing clean, simple callback code?

Question

node.js code is known for turning into callback spaghetti.

What are the best techniques for overcoming this problem and writing clean, uncomplex, easy to understand

Answer 1

Several things can be done to avoid the 'matrioska-style'.

• You can store callbacks to variables:

  var on_read = function (foo, bar) {
        // some logic 
      },
  
      on_insert = function (err, data) {
        someAsyncRead(data, on_read);
      };
  
  someAsyncInsert('foo', on_insert);
  

• You can use some modules that help in those scenarios.

  // Example using funk
  var funk = require('funk');
  for(var i = 0; i < 10; i++) {
    asyncFunction(i, funk.add(function (data) {
      this[i] = data;
    }));
  }
  
  funk.parallel(function () {
    console.log(this);
  });