PropertyDefiner

Module based on Object.defineProperty;

Install

> npm install property-definer;

Import

> ``typescript
> import
> define, {
> defineValue,
> defineAccessor,
> bindDefineValue,
> bindDefineAccessor,
> UNCONFIGURABLE,
> UNENUMERABLE,
> UNWRITABLE
> }
> from 'property-definer'
> `

Description

Here are some enumerations that can generate descriptor more quickly.

1. UNCONFIGURABLE (value: 1) means { configurable: false };
2. UNENUMERABLE (value: 2) means { enumerable: false };
3. UNWRITABLE (value: 4) means { writable: false };

You can generate complete descriptor by mixing these enumerations.

> `typescript
> import { UNCONFIGURABLE, UNENUMERABLE } from "property-definer";
> const descriptor = UNCONFIGURABLE | UNENUMERABLE; // description = 1 | 2;
> const Joker = defineValue({}, "name", "Joker", descriptor);
> // "{\"name\":{\"value\":\"Joker\",\"writable\":false,\"enumerable\":false,\"configurable\":true}}"
> console.log(JSON.stringify(Object.getOwnPropertyDescriptors(Joker)));
> `

1. You can use UNCONFIGURABLE + UNENUMERABLE instead of UNCONFIGURABLE | UNENUMERABLE, because they have equal values;
2. But you can’t use UNCONFIGURABLE + UNCONFIGURABLE instead of UNCONFIGURABLE | UNCONFIGURABLE;

Here we go

$3

Define properties in bulk

> `typescript
> function define(target: object, defines: object, description?: number | string): T;
> `

The define method needs to accept 2~3 arguments,

1. arguments[0]: target Object on which to add or modify the property;
2. arguments[1]: defines JavaScript object that contains one or more descriptor objects. Each descriptor object describes a data property or an accessor property;
3. arguments[2]: description (Optional) Can be a number or a string, See the description section above to learn more;

> `typescript
> import define from 'property-definer';
> var Joker = {};
> define(Joker, {
> name: "Joker",
> gender: { get(){ return "male" } },
> doSomething: { value: "Commit a crime" }
> }, 0);
> console.log({...Joker}); // { name: "Joker", gender: "male", doSomething: "Commit a crime" }
> `

$3

Something like Object.defineProperty(target, key, { value: "some value" });

> `typescript
> function defineValue(target: object, key: PropertyKey, value: any, description?: number | string): object;
> `

The defineValue method needs to accept 3~4 arguments,

1. arguments[0]: target Object on which to add or modify the property;
2. arguments[1]: key The property name, expect string / number / symbol;
3. arguments[2]: value Value of target[key];
4. arguments[3]: description (Optional) Can be a number or a string, See the description section above to learn more;

> `typescript
> /**
> * @description You can also use:
> * @example
> * import { define } from 'property-definer';
> * const { defineValue } = define;
> */
> import { defineValue } from 'property-definer';
> var Joker = {};
> defineValue(Joker, "name", "Joker", UNCONFIGURABLE);
> defineValue(Joker, "gender", "male", UNENUMERABLE);
> defineValue(Joker, "doSomething", "Commit a crime", UNWRITABLE);
> Joker.doSomething = "Be a friendly Gotham citizen"; // Will not take effect
> console.log({...Joker}); // { name: "Joker", doSomething: "Commit a crime" }
> `

$3

Something like Object.defineProperty(target, key, { get(){ return "some thing" }, set(value){ /* do something / } })

> ``typescript
> function defineValue(target: object, key: PropertyKey, accessor: { get?(): any; set?:(value: any): void; }, description?: number | string): object;
> `

The defineAccessor method needs to accept 3~4 arguments,

1. arguments[0]: target Object on which to add or modify the property;
2. arguments[1]: key The property name, expect string / number / symbol;
3. arguments[2]: accessor Object containing Getter or Setter;
4. arguments[3]: description (Optional) Can be a number or a string, See the description section above to learn more;

> `typescript
> /**
> * @description You can also use:
> * @example
> * import { define } from 'property-definer';
> * const { defineAccessor } = define;
> */
> import { defineAccessor } from 'property-definer';
> var Joker = {};
> defineValue(Joker, "name", { get(){ return "Joker" } }, UNCONFIGURABLE);
> defineValue(Joker, "gender", { get(){ return "male" } }, UNENUMERABLE);
> console.log({...Joker}); // { name: "Joker", gender: "male" }
> `

$3

Bind the descriptor, and can also be further bound to the target and key

> `typescript
> function bindDefineValue(description: number | string): (target: object, key: PropertyKey, value: any) => object;
> function bindDefineValue(description: number | string, target: object): (key: PropertyKey, value: any) => object;
> function bindDefineValue(description: number | string, target: object, key: PropertyKey): (value: any) => object;
> `

The bindDefineValue method needs to accept 1~3 arguments,

1. arguments[0]: description Can be a number or a string, See the description section above to learn more;
2. arguments[1]: target (Optional) Object on which to add or modify the property;
3. arguments[2]: key (Optional) The property name, expect string / number / symbol;

> `typescript
> /**
> * @description You can also use:
> * @example
> * import { define } from 'property-definer';
> * const { bindDefineValue } = define;
> */
> import { bindDefineValue } from 'property-definer';
> var Joker = {};
> const bound = bindDefineValue(UNCONFIGURABLE | UNENUMERABLE | UNWRITABLE);
> const boundTarget = bindDefineValue(UNCONFIGURABLE | UNENUMERABLE | UNWRITABLE, Joker);
> const boundTargetAndKey = bindDefineValue(UNCONFIGURABLE | UNENUMERABLE | UNWRITABLE, Joker, "name");
> boundTargetAndKey("Joker");
> boundTarget("gender", "male");
> bound(Joker, "doSomething", "Commit a crime");
> console.log({...Joker}); // { name: "Joker", gender: "male", doSomething: "Commit a crime" }
> `

$3

Bind the descriptor, and can also be further bound to the target and key

> `typescript
> function bindDefineAccessor(description: number | string): (target: object, key: PropertyKey, accessor: { get?(): any; set?:(value: any): void; }) => object;
> function bindDefineAccessor(description: number | string, target: object): (key: PropertyKey, accessor: { get?(): any; set?:(value: any): void; }) => object;
> function bindDefineAccessor(description: number | string, target: object, key: PropertyKey): (accessor: { get?(): any; set?:(value: any): void; }) => object;
> `

The bindDefineValue method needs to accept 1~3 arguments,

1. arguments[0]: description Can be a number or a string, See the description section above to learn more;
2. arguments[1]: target (Optional) Object on which to add or modify the property;
3. arguments[2]: key (Optional) The property name, expect string / number / symbol;

> `typescript
> /**
> * @description You can also use:
> * @example
> * import { define } from 'property-definer';
> * const { bindDefineAccessor } = define;
> */
> import { bindDefineAccessor } from 'property-definer';
> var Joker = {};
> const bound = bindDefineAccessor(UNCONFIGURABLE | UNENUMERABLE);
> const boundTarget = bindDefineAccessor(UNCONFIGURABLE | UNENUMERABLE, Joker);
> const boundTargetAndKey = bindDefineAccessor(UNCONFIGURABLE | UNENUMERABLE, Joker, "name");
> boundTargetAndKey({ get(){ return "Joker" } });
> boundTarget("gender", { get(){ return "male" } });
> bound(Joker, "doSomething", { get(){ return "Commit a crime" } });
> console.log({...Joker}); // { name: "Joker", gender: "male", doSomething: "Commit a crime" }
> ``