phoenix-ui/lib/utils/extend.js

future team ui for app with react

'use strict';

function isObject(obj) {
  return typeof obj === 'object' && obj !== null;
}

/**
*  A recursive merge between two objects.
*
*  @param base     - the object whose properties are to be overwritten. It
*                    should be either the root level or some nested level.
*  @param override - an object containing properties to be overwritten. It
*                    should have the same structure as the object object.
*/
var extend = function extend(base, override) {

  var mergedObject = {};

  //Loop through each key in the base object
  Object.keys(base).forEach(function (key) {

    var baseProp = base[key];
    var overrideProp = undefined;

    if (isObject(override)) overrideProp = override[key];

    //Recursive call extend if the prop is another object, else just copy it over
    mergedObject[key] = isObject(baseProp) && !Array.isArray(baseProp) ? extend(baseProp, overrideProp) : baseProp;
  });

  //Loop through each override key and override the props in the
  //base object
  if (isObject(override)) {

    Object.keys(override).forEach(function (overrideKey) {

      var overrideProp = override[overrideKey];

      //Only copy over props that are not objects
      if (!isObject(overrideProp) || Array.isArray(overrideProp)) {
        mergedObject[overrideKey] = overrideProp;
      }
    });
  }

  return mergedObject;
};

module.exports = extend;