@limetech/mdc-floating-label NPM

Floating Label

Floating labels display the type of input a field requires. Every Text Field and Select should have a label, except for full-width text fields, which use the input's placeholder attribute instead. Labels are aligned with the input line and always visible. They can be resting (when a field is inactive and empty) or floating. The label is a text caption or description for the Text Field.

Design & API Documentation

Installation

npm install @limetech/mdc-floating-label

Basic Usage

HTML Structure

<label class="mdc-floating-label" for="my-text-field-id">Hint text</label>

Styles

@import "@limetech/mdc-floating-label/mdc-floating-label";

JavaScript Instantiation

import {MDCFloatingLabel} from '@limetech/mdc-floating-label';

const floatingLabel = new MDCFloatingLabel(document.querySelector('.mdc-floating-label'));

Variants

Avoid Dynamic ID Generation

If you're using the JavaScript-enabled version of floating label, you can avoid needing to assign a unique id to each <input> by wrapping mdc-text-field__input within a <label>:

<label class="mdc-text-field">
  <input type="text" class="mdc-text-field__input">
  <span class="mdc-floating-label">Hint Text</span>
  <div class="mdc-text-field__bottom-line"></div>
</label>

NOTE: This method also works with <select>.

Style Customization

CSS Classes

CSS Class	Description
`mdc-floating-label`	Mandatory.
`mdc-floating-label--float-above`	Indicates the label is floating in the floating position.
`mdc-floating-label--shake`	Shakes the label.

Sass Mixins

Mixin	Description
`mdc-floating-label-ink-color($color)`	Customizes the ink color of the label.
`mdc-floating-label-fill-color($color)`	Customizes the fill color of the label.
`mdc-floating-label-shake-keyframes($modifier, $positionY, $positionX, $scale)`	Generates a CSS `@keyframes` at-rule for an invalid label shake. Used in conjunction with the `mdc-floating-label-shake-animation` mixin.
`mdc-floating-label-shake-animation($modifier)`	Applies shake keyframe animation to label.
`mdc-floating-label-float-position($positionY, $positionX, $scale)`	Sets position of label when floating.
`mdc-floating-label-max-width($max-width)`	Sets the max width of the label.

`MDCFloatingLabel` Properties and Methods

Method Signature	Description
`shake(shouldShake: boolean) => void`	Proxies to the foundation's `shake()` method.
`float(shouldFloat: boolean) => void`	Proxies to the foundation's `float()` method.
`getWidth() => number`	Proxies to the foundation's `getWidth()` method.

Usage Within Frameworks

If you are using a JavaScript framework, such as React or Angular, you can create a Floating Label 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 here.

`MDCFloatingLabelAdapter`

Method Signature	Description
`addClass(className: string) => void`	Adds a class to the label element.
`removeClass(className: string) => void`	Removes a class from the label element.
`getWidth() => number`	Returns the width of the label element.
`registerInteractionHandler(evtType: string, handler: EventListener) => void`	Registers an event listener for a given event.
`deregisterInteractionHandler(evtType: string, handler: EventListener) => void`	Deregisters an event listener for a given event.

`MDCFloatingLabelFoundation`

Method Signature	Description
`shake(shouldShake: boolean)`	Shakes or stops shaking the label, depending on the value of `shouldShake`.
`float(shouldFloat: boolean)`	Floats or docks the label, depending on the value of `shouldFloat`.
`getWidth() => number`	Returns the width of the label element.