{
  "id": "api/forms/ValidatorFn",
  "title": "ValidatorFn",
  "contents": "\n\n<article>\n  <div class=\"breadcrumb-container\">\n    <div class=\"breadcrumb\">\n      <script type=\"application/ld+json\">\n        {\n          \"@context\": \"http://schema.org\",\n          \"@type\": \"BreadcrumbList\",\n          \"itemListElement\": [\n            { \"@type\": \"ListItem\", \"position\": 1, \"item\": { \"@id\": \"https://angular.io//api\", \"name\": \"API\" } },\n            { \"@type\": \"ListItem\", \"position\": 2, \"item\": { \"@id\": \"https://angular.io/api/forms\", \"name\": \"@angular/forms\" } },\n            { \"@type\": \"ListItem\", \"position\": 3, \"item\": { \"@id\": \"https://angular.io/api/forms/ValidatorFn\", \"name\": \"ValidatorFn\" } }\n          ]\n        }\n      </script>\n        <a href=\"/api\">API</a> > <a href=\"api/forms\">@angular/forms</a>\n    </div>\n    <div class=\"github-links\">\n  <a href=\"https://github.com/angular/angular/edit/master/packages/forms/src/directives/validators.ts?message=docs(forms)%3A%20describe%20your%20change...#L486-L496\" aria-label=\"Suggest Edits\" title=\"Suggest Edits\"><i class=\"material-icons\" aria-hidden=\"true\" role=\"img\">mode_edit</i></a>\n  <a href=\"https://github.com/angular/angular/tree/12.0.0-next.7/packages/forms/src/directives/validators.ts#L486-L496\" aria-label=\"View Source\" title=\"View Source\"><i class=\"material-icons\" aria-hidden=\"true\" role=\"img\">code</i></a>\n</div>\n  </div>\n  \n  <header class=\"api-header\">\n    <h1 id=\"validatorfn\">ValidatorFn<a title=\"Link to this heading\" class=\"header-link\" aria-hidden=\"true\" href=\"api/forms/ValidatorFn#validatorfn\"><i class=\"material-icons\">link</i></a></h1>\n    \n    <label class=\"api-type-label interface\">interface</label>\n    \n    \n    \n  </header>\n  \n  <aio-toc class=\"embedded\"></aio-toc>\n\n  <div class=\"api-body\">\n    \n  <section class=\"short-description\">\n    <p>A function that receives a control and synchronously returns a map of\nvalidation errors if present, otherwise null.</p>\n\n    \n  </section>\n  \n  \n  <section class=\"interface-overview\">\n<code-example language=\"ts\" hidecopy=\"true\">\ninterface <a href=\"api/forms/ValidatorFn\" class=\"code-anchor\">ValidatorFn</a> {\n  <a class=\"code-anchor\" href=\"api/forms/ValidatorFn#call\"><span class=\"member-name\"></span>(control: AbstractControl): ValidationErrors | null</a>\n}\n</code-example>\n\n  \n  \n\n\n  \n  \n\n</section>\n\n  \n\n  \n  \n  \n\n  \n\n<section class=\"instance-methods\">\n  <h2 id=\"methods\">Methods<a title=\"Link to this heading\" class=\"header-link\" aria-hidden=\"true\" href=\"api/forms/ValidatorFn#methods\"><i class=\"material-icons\">link</i></a></h2>\n  \n    <a id=\"call\"></a>\n<table class=\"is-full-width method-table instance-method\">\n  <thead><tr><th>\n    <div class=\"with-github-links\">\n    <h3 id=\"call-signature\">\n      <i>call signature</i>\n      \n    <a title=\"Link to this heading\" class=\"header-link\" aria-hidden=\"true\" href=\"api/forms/ValidatorFn#call-signature\"><i class=\"material-icons\">link</i></a></h3>\n    <div class=\"github-links\">\n  <a href=\"https://github.com/angular/angular/edit/master/packages/forms/src/directives/validators.ts?message=docs(forms)%3A%20describe%20your%20change...#L495-L495\" aria-label=\"Suggest Edits\" title=\"Suggest Edits\"><i class=\"material-icons\" aria-hidden=\"true\" role=\"img\">mode_edit</i></a>\n  <a href=\"https://github.com/angular/angular/tree/12.0.0-next.7/packages/forms/src/directives/validators.ts#L495-L495\" aria-label=\"View Source\" title=\"View Source\"><i class=\"material-icons\" aria-hidden=\"true\" role=\"img\">code</i></a>\n</div>\n    </div>\n  </th></tr></thead>\n  <tbody>\n    \n  \n    <tr>\n      <td>\n        <div class=\"overload-info\">\n  \n\n  <code-example language=\"ts\" hidecopy=\"true\" class=\"no-box api-heading\"><span class=\"member-name\"></span>(control: <a href=\"api/forms/AbstractControl\" class=\"code-anchor\">AbstractControl</a>): <a href=\"api/forms/ValidationErrors\" class=\"code-anchor\">ValidationErrors</a> | null</code-example>\n\n  \n\n  <h6 class=\"no-anchor\" id=\"parameters\">Parameters</h6>\n  <table class=\"is-full-width list-table parameters-table instance-method-overload-parameters\">\n  <tbody>\n  \n    <tr class=\"instance-method-overload-parameter\">\n      <td class=\"param-name\">\n        <a id=\"\"></a>\n        <code>control</code>\n      </td>\n      <td class=\"param-type\"><code><a href=\"api/forms/AbstractControl\" class=\"code-anchor\">AbstractControl</a></code></td>\n      <td class=\"param-description\">\n                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     \n                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               \n      </td>\n    </tr>\n  </tbody>\n</table>\n\n  \n  <h6 class=\"no-anchor\" id=\"returns\">Returns</h6>\n  <p><code><a href=\"api/forms/ValidationErrors\" class=\"code-anchor\">ValidationErrors</a> | null</code></p>\n\n  \n\n\n  \n\n  \n</div>\n      </td>\n    </tr>\n  \n\n  \n\n  \n    </tbody>\n</table>\n\n  \n</section>\n\n\n  \n\n\n  </div>\n</article>\n\n<!-- links to this doc:\n - api/forms\n - api/forms/AbstractControl\n - api/forms/AbstractControlDirective\n - api/forms/AbstractControlOptions\n - api/forms/FormArray\n - api/forms/FormBuilder\n - api/forms/FormControl\n - api/forms/FormGroup\n - api/forms/Validators\n - guide/form-validation\n-->\n<!-- links from this doc:\n - /api\n - api/forms\n - api/forms/AbstractControl\n - api/forms/ValidationErrors\n - api/forms/ValidatorFn#call\n - api/forms/ValidatorFn#call-signature\n - api/forms/ValidatorFn#methods\n - api/forms/ValidatorFn#validatorfn\n - https://github.com/angular/angular/edit/master/packages/forms/src/directives/validators.ts?message=docs(forms)%3A%20describe%20your%20change...#L486-L496\n - https://github.com/angular/angular/edit/master/packages/forms/src/directives/validators.ts?message=docs(forms)%3A%20describe%20your%20change...#L495-L495\n - https://github.com/angular/angular/tree/12.0.0-next.7/packages/forms/src/directives/validators.ts#L486-L496\n - https://github.com/angular/angular/tree/12.0.0-next.7/packages/forms/src/directives/validators.ts#L495-L495\n-->"
}