object-path
Access deep properties using a path
Changelog
0.11.0
- Introduce ability to specify options and create new instances of
object-path - Introduce option to control the way
object-pathdeals with inherited properties (includeInheritedProps) - New default
object-pathinstance already configured to handle not-own object properties (withInheritedProps)
0.10.0
- Improved performance of
get,set, andpushby 2x-3x - Introduced a benchmarking test suite
- BREAKING CHANGE:
del,empty,setwill not affect not-own object's properties (made them consistent with the other methods)
Install
Node.js
npm install object-path --save
Bower
bower install object-path --save
Typescript typings
typings install --save dt~object-path
Usage
var obj = {
a: {
b: "d",
c: ["e", "f"],
'\u1200': 'unicode key',
'dot.dot': 'key'
}
};
var objectPath = require("object-path");
//get deep property
objectPath.get(obj, "a.b"); //returns "d"
objectPath.get(obj, ["a", "dot.dot"]); //returns "key"
objectPath.get(obj, 'a.\u1200'); //returns "unicode key"
//get the first non-undefined value
objectPath.coalesce(obj, ['a.z', 'a.d', ['a','b']], 'default');
//empty a given path (but do not delete it) depending on their type,so it retains reference to objects and arrays.
//functions that are not inherited from prototype are set to null.
//object instances are considered objects and just own property names are deleted
objectPath.empty(obj, 'a.b'); // obj.a.b is now ''
objectPath.empty(obj, 'a.c'); // obj.a.c is now []
objectPath.empty(obj, 'a'); // obj.a is now {}
//works also with arrays
objectPath.get(obj, "a.c.1"); //returns "f"
objectPath.get(obj, ["a","c","1"]); //returns "f"
//can return a default value with get
objectPath.get(obj, ["a.c.b"], "DEFAULT"); //returns "DEFAULT", since a.c.b path doesn't exists, if omitted, returns undefined
//set
objectPath.set(obj, "a.h", "m"); // or objectPath.set(obj, ["a","h"], "m");
objectPath.get(obj, "a.h"); //returns "m"
//set will create intermediate object/arrays
objectPath.set(obj, "a.j.0.f", "m");
//will insert values in array
objectPath.insert(obj, "a.c", "m", 1); // obj.a.c = ["e", "m", "f"]
//push into arrays (and create intermediate objects/arrays)
objectPath.push(obj, "a.k", "o");
//ensure a path exists (if it doesn't, set the default value you provide)
objectPath.ensureExists(obj, "a.k.1", "DEFAULT");
var oldVal = objectPath.ensureExists(obj, "a.b", "DEFAULT"); // oldval === "d"
//deletes a path
objectPath.del(obj, "a.b"); // obj.a.b is now undefined
objectPath.del(obj, ["a","c",0]); // obj.a.c is now ['f']
//tests path existence
objectPath.has(obj, "a.b"); // true
objectPath.has(obj, ["a","d"]); // false
//bind object
var model = objectPath({
a: {
b: "d",
c: ["e", "f"]
}
});
//now any method from above is supported directly w/o passing an object
model.get("a.b"); //returns "d"
model.get(["a.c.b"], "DEFAULT"); //returns "DEFAULT"
model.del("a.b"); // obj.a.b is now undefined
model.has("a.b"); // false
How object-path deals with inherited properties
By default object-path will only access an object's own properties. Look at the following example:
var proto = {
notOwn: {prop: 'a'}
}
var obj = Object.create(proto);
//This will return undefined (or the default value you specified), because notOwn is
//an inherited property
objectPath.get(obj, 'notOwn.prop');
//This will set the property on the obj instance and not the prototype.
//In other words proto.notOwn.prop === 'a' and obj.notOwn.prop === 'b'
objectPath.set(obj, 'notOwn.prop', 'b');
To configure object-path to also deal with inherited properties, you need to create a new instance and specify
the includeInheritedProps = true in the options object:
var objectPath = require("object-path");
var objectPathWithInheritedProps = objectPath.create({includeInheritedProps: true})
Alternatively, object-path exposes an instance already configured to handle inherited properties (objectPath.withInheritedProps):
var objectPath = require("object-path");
var objectPathWithInheritedProps = objectPath.withInheritedProps
Once you have the new instance, you can access inherited properties as you access other properties:
var proto = {
notOwn: {prop: 'a'}
}
var obj = Object.create(proto);
//This will return 'a'
objectPath.withInheritedProps.get(obj, 'notOwn.prop');
//This will set proto.notOwn.prop to 'b'
objectPath.set(obj, 'notOwn.prop', 'b');
Immutability
If you are looking for an immutable alternative of this library, you can take a look at: object-path-immutable
Credits
- Mario Casciaro - Author
- Paulo Cesar - Major contributor