Form Fields
MDC Form Field aligns an MDC Web form field (for example, a checkbox) with its label and makes it RTL-aware. It also activates a
Installation
npm install @material/form-field
Demos
Basic Usage
HTML Structure
Use the mdc-form-field element to wrap any combination of adjacent input and label elements of MDC Web form controls, such as
xxxxxxxxxx
<div class="mdc-form-field">
<div class="mdc-checkbox">
<input type="checkbox" id="my-checkbox" class="mdc-checkbox__native-control"/>
<div class="mdc-checkbox__background">
...
</div>
</div>
<label for="my-checkbox">This is my checkbox</label>
</div>
NOTE: MDC Form Field is not intended for cases where a label and input are already handled together in a component's styles and logic. For example,
MDC Text Field already manages a label and input together under its own root element.
JavaScript Instantiation
If you are using MDC Form Field with an MDC Web component that has a
import {MDCFormField} from '@material/form-field';
import {MDCCheckbox} from '@material/checkbox';
const formField = new MDCFormField(document.querySelector('.mdc-form-field'));
const checkbox = new MDCCheckbox(document.querySelector('.mdc-checkbox'));
formField.input = checkbox;
See
Importing the JS component for more information on how to import JavaScript.
Variants
Label position
By default, the input will be positioned before the label. You can position the input after the label by adding the mdc-form-field--align-end class:
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<div class="mdc-form-field mdc-form-field--align-end">
<div class="mdc-checkbox">
<input type="checkbox" id="my-checkbox" class="mdc-checkbox__native-control"/>
<div class="mdc-checkbox__background">
...
</div>
</div>
<label for="my-checkbox">This is my checkbox</label>
</div>
Nowrap
If the label text is too long for a single line, it will wrap the text by default. You can force the text to stay on a single line and ellipse the overflow text by adding the mdc-form-field--nowrap class:
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<div class="mdc-form-field mdc-form-field--nowrap">
<div class="mdc-checkbox">
<input type="checkbox" id="my-checkbox" class="mdc-checkbox__native-control"/>
<div class="mdc-checkbox__background">
...
</div>
</div>
<label for="my-checkbox">This some really really really long text</label>
</div>
MDCFormField Properties and Methods
Property | Value Type | Description |
---|---|---|
input | String | Gets and sets the form field input. |
In order for the label ripple integration to work correctly, the input property needs to be set to a valid instance of an MDC Web input element which exposes a ripple getter. No action is taken if the input property is not set or the input instance doesn't expose a ripple getter.
Usage within Web Frameworks
If you are using a JavaScript framework, such as React or Angular, you can create a Form Field for your framework. Depending on your needs, you can use the Simple Approach: Wrapping MDC Web Vanilla Components, or the Advanced Approach: Using Foundations and Adapters. Please follow the instructions
MDCFormFieldAdapter
Method Signature | Description |
---|---|
registerInteractionHandler(type: string, handler: EventListener) => void | Adds an event listener handler for event type type to the label. |
deregisterInteractionHandler(type: string, handler: EventListener) => void | Removes an event listener handler for event type type to the label. |
activateInputRipple() => void | Activates the ripple on the input element. Should call activate on the input element's ripple property. |
deactivateInputRipple() => void | Deactivates the ripple on the input element. Should call deactivate on the input element's ripple property. |