Sync URL Query Params with Angular Form Controls
The library provides a simple and reusable solution for binding URL query params to Angular Forms
npm install @ngneat/bind-query-params
Inject the BindQueryParamsFactory provider, pass an array of definitions and connect it to your form:
import { BindQueryParamsFactory } from '@ngneat/bind-query-params';
interface Filters {
  searchTerm: string;
  someBoolean: boolean;
}
@Component({
  template: `Your normal form setup`,
})
export class MyComponent {
  filters = new FormGroup({
    searchTerm: new FormControl(),
    someBoolean: new FormControl(false),
  });
  bindQueryParamsManager = this.factory
    .create<Filters>([
      { queryKey: 'searchTerm' },
      { queryKey: 'someBoolean', type: 'boolean' }
     ]).connect(this.filters);
  constructor(private factory: BindQueryParamsFactory) {}
  ngOnDestroy() {
    this.bindQueryParamsManager.destroy();
  }
}With this setup, the manager will take care of two things:
- Update the 
control's value when the page is loaded for the first time - Update the URL query parameter when the corresponding 
controlvalue changes 
The query parameter key
The form control path. If it is not specified, the manager assumes that the path is the queryKey. We can also pass nested keys, for example, person.name:
{ queryKey: 'name', path: 'person.name' }Specify the control value type. Available options are:
boolean, array, number, string and object.
Before updating the control with the value, the manager will parse it based on the provided type.
Provide a custom parser. For example, the default array parser converts the value to an array of strings. If we need it to be an array of numbers, we can pass the following parser:
const def = { parser: (value) => value.split(',').map((v) => +v) };Provide a custom serializer. For example, supposing that we have a FormControl that carries a Date and we want to persist, in the query params, a custom value, such as a string Date, we can do something like the following serializer:
const def = { serializer: (value) => (value instanceof Date ? value.toISOString().slice(0, 10) : (value as string)) };When working with async control values, for example, a dropdown list that its options come from the server, we cannot immediately update the control.
In this cases, we can provide the modelToUrl strategy, that will not update the control value when the page loads. When the data is available we can call the manager.syncDefs() method that'll update the controls based on the current query params:
@Component()
export class MyComponent {
  filters = new FormGroup({
    searchTerm: new FormControl(),
    users: new FormControl([]),
    someBoolean: new FormControl(false),
  });
  bindQueryParamsManager = this.factory
    .create<Filters>([
      { queryKey: 'searchTerm' },
      { queryKey: 'someBoolean', type: 'boolean' },
      { queryKey: 'users', type: 'array', strategy: 'modelToUrl' },
    ])
    .connect(this.filters);
  constructor(private factory: BindQueryParamsFactory) {}
  ngOnInit() {
    service.getUsers().subscribe((users) => {
      // Initalize the dropdown
      this.users = users;
      this.manager.syncDefs('users');
    });
  }
  ngOnDestroy() {
    this.bindQueryParamsManager.destroy();
  }
}Note that syncDefs will always be called once under the hood.
The library uses the URLSearchParams API, which supported in any browser except IE.
Thanks goes to these wonderful people (emoji key):
Netanel Basal π» π π π€ π  | 
  
This project follows the all-contributors specification. Contributions of any kind welcome!
