Utility for modifying / processing the contents of Javascript objects or arrays via object notation strings or globs.
npm install notation
> © 2020, Onur Yıldırım (@onury). MIT License.
Utility for modifying / processing the contents of JavaScript objects and arrays, via object or bracket notation strings or globs. (Node and Browser)
``js`
Notation.create({ x: 1 }).set('some.prop', true).filter(['*.prop']).value // { some: { prop: true } }
> _Note that this library should be used to manipulate data objects with enumerable properties. It will NOT deal with preserving the prototype-chain of the given object or objects with circular references._
Install via NPM:
`sh`
npm i notation
In Node/CommonJS environments:js`
const { Notation } = require('notation');
With transpilers (TypeScript, Babel):js`
import { Notation } from 'notation';
In (Modern) Browsers:html`
is a class for modifying or inspecting the contents (property keys and values) of a data object or array.When reading or inspecting an enumerable property value such as
obj.very.deep.prop; with pure JS, you would have to do several checks:
`js
if (obj
&& obj.hasOwnProperty('very')
&& obj.very.hasOwnProperty('deep')
&& obj.very.deep.hasOwnProperty('prop')
) {
return obj.very.deep.prop === undefined ? defaultValue : obj.very.deep.prop;
}
`
With , you could do this:
`js
const notate = Notation.create;
return notate(obj).get('very.deep.prop', defaultValue);
`
You can also inspect & get the value:
js
console.log(notate(obj).inspectGet('very.deep.prop'));
// {
// notation: 'very.deep.prop',
// has: true,
// value: 'some value',
// type: 'string',
// level: 3,
// lastNote: 'prop'
// }
`To modify or build a data object:
js
const notate = Notation.create;
const obj = { car: { brand: "Dodge", model: "Charger" }, dog: { breed: "Akita" } };
notate(obj) // initialize. equivalent to new Notation(obj)
.set('car.color', 'red') // { car: { brand: "Dodge", model: "Charger", color: "red" }, dog: { breed: "Akita" } }
.remove('car.model') // { car: { brand: "Dodge", color: "red" }, dog: { breed: "Akita" } }
.filter(['*', '!car']) // { dog: { breed: "Akita" } } // equivalent to .filter(['dog'])
.flatten() // { "dog.breed": "Akita" }
.expand() // { dog: { breed: "Akita" } }
.merge({ 'dog.color': 'white' }) // { dog: { breed: "Akita", color: "white" } }
.copyFrom(other, 'boat.name') // { dog: { breed: "Akita", color: "white" }, boat: { name: "Mojo" } }
.rename('boat.name', 'dog.name') // { dog: { breed: "Akita", color: "white", name: "Mojo" } }
.value; // result object ^
See [API Reference][docs] for more...Glob Notation
With a glob-notation, you can use wildcard stars
and bang ! prefix. A wildcard star will include all the properties at that level and a bang prefix negates that notation for exclusion.- Only
Notation#filter() method accepts glob notations. Regular notations (without any wildcard * or ! prefix) should be used with all other members of the Notation class.
- For raw Glob operations, you can use the Notation.Glob class.$3
Removes duplicates, redundant items and logically sorts the array:
`js
const { Notation } = require('notation');const globs = ['', '!id', 'name', 'car.model', '!car.', 'id', 'name', 'age'];
console.log(Notation.Glob.normalize(globs));
// ——» ['', '!car.', '!id', 'car.model']
`In the normalized result
:
- id is removed and !id (negated version) is kept. (In normalization, negated always wins over the positive, if both are same).
- Duplicate glob, name is removed. The remaining name is also removed bec. * renders it redundant; which covers all possible notations.
- (In non-restrictive mode) car.model is kept (although matches it) bec. it's explicitly defined while we have a negated glob that also matches it: !car..`js
console.log(Notation.Glob.normalize(globs, { restrictive: true }));
// ——» ['', '!car.', '!id']
`
- In restrictive mode, negated removes every match.> _Note:
and Notation.Glob.union() methods automtically pre-normalize the given glob list(s)._$3
Unites two glob arrays optimistically and sorts the result array logically:
`js
const globsA = ['', '!car.model', 'car.brand', '!.age'];
const globsB = ['car.model', 'user.age', 'user.name'];
const union = Notation.Glob.union(globsA, globsB);
console.log(union);
// ——» ['', '!.age', 'user.age']
`
In the united result :
- (negated) !car.model of globsA is removed because globsB has the exact positive version of it. (In union, positive wins over the negated, if both are same.)
- But then, car.model is redundant and removed bec. we have * wildcard, which covers all possible non-negated notations.
- Same applies to other redundant globs except user.age bec. we have a !*.age in globsA, which matches user.age. So both are kept in the final array.Filtering Data with Glob patterns
When filtering a data object with a globs array; properties that are explicitly defined with globs or implied with wildcards, will be included. Any matching negated-pattern will be excluded. The resulting object is created from scratch without mutating the original.
`js
const data = {
car: {
brand: 'Ford',
model: 'Mustang',
age: 52
},
user: {
name: 'John',
age: 40
}
};
const globs = ['', '!.age', 'user.age'];
const filtered = Notation.create(data).filter(globs).value;
console.log(filtered);
// ——»
// {
// car: {
// brand: 'Ford',
// model: 'Mustang'
// },
// user: {
// name: 'John',
// age: 40
// }
// }
`In non-restrictive mode; even though we have the
negated glob; user.age is still included in the result because it's explicitly defined. But you can also do restrictive filtering. Let's take the same example:
`js
const globs = ['', '!.age', 'user.age'];
const filtered = Notation.create(data).filter(globs, { restrictive: true }).value;
console.log(filtered);
// ——»
// {
// car: {
// brand: 'Ford',
// model: 'Mustang'
// },
// user: {
// name: 'John'
// }
// }
`
Note that in restrictive mode, is removed this time; due to !*.age pattern.Object and Bracket Notation Syntax
Each note (level) of a notation is validated against EcmaScript variable syntax, array index notation and object bracket notation.
$3
- x[y], x.1, x.y-z, x.@ are incorrect and will never match.
- x["y"], x['1'], x["y-z"], x['@'] are correct object bracket notations. $3
- [0].x indicates x property of the first item of the root array.
- x[1] indicates second item of x property of the root object.$3
- * is valid wildcard for glob notation. Indicates all properties of an object.
- [*] is valid wildcard for glob notation. Indicates all items of an array.
- x[*] is valid wildcard for glob notation. Indicates all items of x property which should be an array.
- x['*'] just indicates a property/key (star), not a wildcard. Valid regular notation.
- x.* is valid wildcard for glob notation.
- x, x. and x..* (and so on) are all equivalent globs. All normalize to x.
- Negated versions are NOT equivalent.
- !x indicates removal of x.
- !x.* only indicates removal of all first-level properties of x but not itself (empty object).
- !x.. only indicates removal of all second-level properties of x; but not itself and its first-level properties (x.*).
- Same rule applies for bracket notation or mixed notations.
- [0] = [0][] but ![0] ≠ ![0][]
- = x[] but !x ≠ !x[]
- = []. but ![] ≠ ![].$3
Below, we filter to;
- keep all properties of the source object,
- remove the second item of property (which is an array),
- and empty my-colors property (which is an object).
`js
const source = {
name: 'Jack',
colors: ['blue', 'green', 'red'],
'my-colors': { '1': 'yellow' } // non-standard name "my-colors"
};
const globs = ['', '!colors[1]', '!["my-colors"].'];
console.log(Notation.create(source).filter(globs).value);
// —»
// {
// name: 'Jack',
// colors: ['blue', 'red'],
// 'my-colors': {}
// }
`
In the example above, item at index 1 is emptied.Globs and Data Integrity
$3
In a glob list, you cannot have both object and array notations for root level. The root level implies the source type which is either an object or array; never both.For example,
['[*]', '!x.y'] will throw because when you filter a source array with this glob list; !x.y will never match since the root x indicates an object property (e.g. source.x).$3
Each glob you use should conform with the given source object.For example:
`js
const obj = { x: { y: 1 } };
const globs = ['', '!x.'];
console.log(Notation.create(obj).filter(globs).value);
// ——» { x: {} }
`
Here, we used negated glob to remove all the properties of x but not itself. So the result object has an x property with an empty object as its value. All good.But in the source object; if the actual value of
x is not an object, using the same glob list would throw:
`js
const obj = { x: 1 }; // x is number
const globs = ['', '!x.'];
console.log(Notation.create(obj).filter(globs).value);
// ——» ERROR
`
This kind of type mismatch is critical so it will throw. The value is a Number not an object, so it cannot be emptied with !x.*. (But we could have removed it instead, with glob !x.)Source Object Mutation
The source object or array will be mutated by default (except the
#filter() method). To prevent mutation; you can call #clone() method before calling any method that modifies the object. The source object will be cloned deeply.`js
const notate = Notation.create;const mutated = notate(source1).set('newProp', true).value;
console.log(source1.newProp); // ——» true
const cloned = notate(source2).clone().set('newProp', true).value;
console.log('newProp' in source2); // ——» false
console.log(cloned.newProp); // ——» true
`> _Note that
expects a data object (or array) with enumerable properties. In addition to plain objects and arrays; supported cloneable property/value types are primitives (such as String, Number, Boolean, Symbol, null and undefined) and built-in types (such as Date and RegExp)._
>
> _Enumerable properties with types other than these (such as methods, special objects, custom class instances, etc) will be copied by reference. Non-enumerable properties will not be cloned._
>
> _If you still need full clone support, you can use a library like lodash. e.g. Notation.create(_.cloneDeep(source))_Documentation
You can read the full [API reference here][docs].
Change-Log
Read the [CHANGELOG][changelog] especially if you're migrating from version
1.x.x to version 2.0.0` and above.MIT.
[docs]:https://onury.io/notation/api
[changelog]:https://github.com/onury/notation/blob/master/CHANGELOG.md