{"id":3021,"date":"2023-11-23T18:02:36","date_gmt":"2023-11-23T17:02:36","guid":{"rendered":"https:\/\/nguenkam.com\/blog\/?p=3021"},"modified":"2023-11-23T21:49:49","modified_gmt":"2023-11-23T20:49:49","slug":"how-to-enable-the-use-of-the-validators-required-on-a-custom-component","status":"publish","type":"post","link":"https:\/\/nguenkam.com\/blog\/index.php\/2023\/11\/23\/how-to-enable-the-use-of-the-validators-required-on-a-custom-component\/","title":{"rendered":"How do I enable the use of Validators.required for a custom component?"},"content":{"rendered":"\n

Let us assume, we have a custom Angular component that acts as a form control and we want to enable the use of the “Validators.required<\/code>” <\/strong>validator on it.<\/p>\n\n\n\n

Assuming the custom control component has the name MyCustomControlComponent<\/code><\/span><\/em>, here’s how we can enable the use of Validators.required<\/code>:<\/p>\n\n\n\n

  1. Import Necessary Angular Forms Modules:<\/strong><\/li><\/ol>\n\n\n\n

    Make sure to import the necessary Angular forms modules in your custom control component.<\/p>\n\n\n\n

    import { Component, forwardRef } from '@angular\/core';\nimport { ControlValueAccessor, NG_VALUE_ACCESSOR, NG_VALIDATORS, Validator, Validators, AbstractControl } from '@angular\/forms';\n<\/code><\/pre>\n\n\n\n
    2. Implement ControlValueAccessor and Validator Interfaces:<\/strong><\/p>\n\n\n\n
    Ensure that our custom control component implements the ControlValueAccessor<\/code> and Validator<\/code> interfaces.<\/p>\n\n\n\n
    @Component({\n  selector: 'app-my-custom-control',\n  template: `\n    <!-- our custom control implementation -->\n    <input [(ngModel)]=\"value\" \/>\n  `,\n  providers: [\n    {\n      provide: NG_VALUE_ACCESSOR,\n      useExisting: forwardRef(() => MyCustomControlComponent),\n      multi: true,\n    },\n    {\n      provide: NG_VALIDATORS,\n      useExisting: forwardRef(() => MyCustomControlComponent),\n      multi: true,\n    },\n  ],\n})\nexport class MyCustomControlComponent implements ControlValueAccessor, Validator {\n  value: any;\n\n  \/\/ ControlValueAccessor methods and properties\n\n  \/\/ Validator interface method\n  validate(control: AbstractControl): { [key: string]: any } | null {\n    return Validators.required(control);\n  }\n}\n<\/code><\/pre>\n\n\n\n
    PS:<\/span> “NG_VALIDATORS<\/code><\/strong>” is provided, and the “validate<\/strong><\/code>” method is implemented to apply the Validators.required<\/strong><\/code> validation.<\/p>\n\n\n\n
    3. Use the Custom Control in a Form:<\/strong><\/p>\n\n\n\n
    Now we can use our custom control component in a form, and the Validators.required<\/code> validator will be applied to it.<\/p>\n\n\n\n
    import { Component } from '@angular\/core';\nimport { FormBuilder, FormGroup } from '@angular\/forms';\n\n@Component({\n  selector: 'app-my-form',\n  template: `\n    <form [formGroup]=\"myForm\">\n      <app-my-custom-control formControlName=\"myCustomControl\"><\/app-my-custom-control>\n    <\/form>\n  `,\n})\nexport class MyFormComponent {\n  myForm: FormGroup;\n\n  constructor(private fb: FormBuilder) {\n    this.myForm = this.fb.group({\n      myCustomControl: [null, Validators.required],\n    });\n  }\n}\n<\/code><\/pre>\n\n\n\n
    Now, when we use Validators.required<\/code> in the form control definition for myCustomControl<\/code>, it will be applied to our custom control component.<\/p>\n\n\n\n
    See also the link : Angular : Implementing  Control Value Accessor<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
    Let us assume, we have a custom Angular component that acts as a form control and we want to enable the use of the “Validators.required” validator on it. Assuming the custom control component has the name MyCustomControlComponent, here’s how we can enable the use of Validators.required: Import Necessary Angular Forms Modules: Make sure to import […]<\/p>\n","protected":false},"author":1,"featured_media":1965,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[37],"tags":[676,679,768,675,770,769,771],"_links":{"self":[{"href":"https:\/\/nguenkam.com\/blog\/index.php\/wp-json\/wp\/v2\/posts\/3021"}],"collection":[{"href":"https:\/\/nguenkam.com\/blog\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nguenkam.com\/blog\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nguenkam.com\/blog\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/nguenkam.com\/blog\/index.php\/wp-json\/wp\/v2\/comments?post=3021"}],"version-history":[{"count":2,"href":"https:\/\/nguenkam.com\/blog\/index.php\/wp-json\/wp\/v2\/posts\/3021\/revisions"}],"predecessor-version":[{"id":3026,"href":"https:\/\/nguenkam.com\/blog\/index.php\/wp-json\/wp\/v2\/posts\/3021\/revisions\/3026"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nguenkam.com\/blog\/index.php\/wp-json\/wp\/v2\/media\/1965"}],"wp:attachment":[{"href":"https:\/\/nguenkam.com\/blog\/index.php\/wp-json\/wp\/v2\/media?parent=3021"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nguenkam.com\/blog\/index.php\/wp-json\/wp\/v2\/categories?post=3021"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nguenkam.com\/blog\/index.php\/wp-json\/wp\/v2\/tags?post=3021"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}