Object path accessor. Tests, provides and sets values within objects and arrays.
$ npm install --save @konfirm/tailspin
Provide an object and a path (as string) to the tailspin module and a new Tail object is returned.
const tailspin = require('@konfirm/tailspin');
const subject = { foo: { bar: { baz: 1 } } };
const tail = tailspin(subject, 'foo.bar.baz');
console.log(tail.value); // 1
Create a Tail-instance to interact with the provided path within the scope.
A Tail object is what is returned by the tailspin-function, it provides several members to interact with the provided target/path.
All of the examples in the API outline below use the tail created in the example in usage.
Obtain the value of the Tail-object.
console.log(tail.value); // 1
Modify the value of the Tail-object, can be forced in case the path in itself is not reachable.
tail.modify(2); // returns true, success
console.log(tail.value); // 2
Obtain the type of the Tail-object. Returns one of the regular javascript typeof types ('boolean', 'number', 'string', 'object', 'null' or 'undefined'), or 'array' in case the value is an array.
console.log(tail.type); // number
Obtain all types encountered during traversal of the path leading up to the Tail-object. Uses the same values for types as provided by type.
console.log(tail.types); // [ 'object', 'object', 'number' ]
// ^ foo ^ bar ^ baz
Determine whetehr the path of the Tail-object is actually reachable. Reachable in this context means whether of not the path exists or can be created without changing any type other than array, object or undefined.
console.log(tail.reachable); // true
If any value of the path is not capable (or desirable) to have a property, it is considered to be unreachable. For example, one cannot set a property to a number value.
const subject = { num: 1 };
const tail = tailspin(subject, 'num.property');
console.log(tail.reachable); // false
Obtain the scope of the Tail-object. This will be the "parent" Tail-object, if any.
console.log(tail.scope);
MIT License Copyright (c) 2017 Rogier Spieker (Konfirm)
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