retrieve-object-child

retrieve-object-child (NodeJS)

Retrieve child objects from an object.

Installation

First get the package from NPM

npm install retrieve-object-child

And now simply require it in your application

var retrieveChild = require('retrieve-object-child');

Api

/**
 * @param  {Object} object
 * @param  {string|array} position - Key or an array containing keys.
 * @param  {boolean} insert - Create the child object if it doesn't exist.
 * @param  {boolean} throwConflicts - Throw an error if there are conflicts.
 * @return {Object|undefined} - The child object or undefined if none was found.
 */
function retrieveChild(object, position, insert, throwConflicts)

Usage

First up is the most basic format of usage of this function with all the default parameters:

object.customNested = {};
object.customNested.deeper = {};

var child = retrieveChild(object, ['customNested', 'deeper']);
child === object.customNested.deeper

It will return undefined when the child does not exist

var child = retrieveChild(object, 'non_existent');
child === undefined

or when there's a conflict

object.customNested = "not an object";

var child = retrieveChild(object, ['customNested', 'deeper']);
child === undefined

insert enabled

Retrieving existing objects works the same way, but when trying to access an unexisting object path, it will build one recursively.

object = {};
var child = retrieveChild(object, ['customNested', 'deeper'], true);
child === object.customNested.deeper

or will override all children when there's a conflict.

object.customNested = "not an object";

var child = retrieveChild(object, ['customNested', 'deeper'], true);
child === object.customNested.deeper

throwConflict enabled

An error will be thrown whenever there's a conflict instead of falling back on the default behavior.

object.customNested = "some primitive type like a string";

try {
  retrieveChild(object, ['customNested', 'deeper'], false, true);
} catch (e) {
  e.message === 'Conflict detected at key customNested on position 0'
  e.key === 'customNested'
  e.index === 0
}

As you can see, you can find out exactly where a conflict has been detected.

Test

grunt test

License

MIT.