Skip to main content

FAQ

Rendering Dynamic HTML template using ngx-formly at runtime​

it's not possible due to Angular limitation on that part (require to use Angular compiler in browser), so instead use one of the following solutions:

1- create a Custom component type

2- use expressions:

{
  expressions: {
    template: field => `<div>${field.model.label}</div>`
  }
}

3- use inline type:

@Component({
  selector: 'app',
  template: `
    <formly-form [form]="form" [fields]="fields" [model]="model">
+     <ng-template formlyTemplate="custom-inline-type" let-field>
+        Hello {{ field.props.name }}
+     </ng-template>
    </formly-form>
  `,
})
export class AppComponent {
  ...
  fields: FormlyFieldConfig[] = [
    {
+     type: 'custom-inline-type',
+     props: {
        name: 'World !!!',
      }
    }
  ];
}

How to access to the parent field model value:​

To access into the main model you have to use:

What is hooks in Formly​

The hooks are callbacks that give you the opportunity to interact with the field instance when an event happens in the field's life cycle. The most relevant hooks are:

  • onInit: Called once, after the after field has been initialized;
  • afterViewInit: Called after Angular initializes the component's views and child views.
  • onDestroy: Called before Angular destroys the field component.

Usage​

fields: FormlyFieldConfig[] = [
  {
    type: 'input',
    hooks: {
      onInit: (field) => {
        const { form, model, options } = field;
        ...
      },
    },
  }
];

What does templateOptions and props in Formly:​

templateOptions is an alias to props, which allows passing extra option to the field ui template. For example we can use it to pass a custom label/placeholder or set the input field as required.

Usage​

The following example will mark the field as required and set label to Name

fields: FormlyFieldConfig[] = [
  {
    type: 'input',
    props: {
      label: 'Name',
      required: true
    },
  }
];

The pipe formlySelectOptions could not be found​

If you receive a 'pipe could not be found' error, such as the one below, make sure to import the necessary modules.

Template parse errors:
The pipe 'formlySelectOptions' could not be found

In this error, the formlySelectOptions pipe is part of FormlySelectModule. This must be imported into the application before templates, including your custom templates, can use the pipe.

import { FormlySelectModule } from '@ngx-formly/core/select';

@NgModule({
  imports: [
    ...
    FormlySelectModule,
  ],
})
export class AppModule { }

Formly standalone components support​

Standalone components support will be added in the next major version (v7) of Formly. In the meantime, you can use the following solution: https://github.com/ngx-formly/ngx-formly/issues/3721#issuecomment-1602401526.

How to add className to formly-field component:​

If you want to apply a custom style for a specific field, use className property:

{
  className: 'custom-class',
  key: 'name',
  ...
}

Result:

<formly-field class="custom-class">...<formly-field>

How to apply style to a child element of field ?​

use className which will be added to the formly-field component and then target the child element using css:

{
  className: 'my-custom-style',
  key: 'name',
  ...
}

style.scss:

.my-custom-style .mat-form-field {
}