@limetech/mdc-floating-label

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

• Material Design guidelines: Text Fields Layout
• Demo with Text Field

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.