Bài 24: Input : tìm hiểu ion-textarea

 

ion-textarea

Thành phần textarea được sử dụng để nhập văn bản nhiều dòng. Một phần tử textarea gốc được hiển thị bên trong thành phần. Trải nghiệm người dùng và tính tương tác của thành phần văn bản được cải thiện bằng cách kiểm soát vùng văn bản gốc.

Không giống như phần tử textarea gốc, Ionic textarea không hỗ trợ tải giá trị của nó từ nội dung bên trong. Giá trị vùng văn bản phải được đặt trong valuethuộc tính.

Thành phần textarea chấp nhận các native textarea attributes ngoài các thuộc tính Ionic.

 Usage

<!-- Default textarea -->
<ion-textarea></ion-textarea>

<!-- Textarea in an item with a placeholder -->
<ion-item>
  <ion-textarea placeholder="Enter more information here..."></ion-textarea>
</ion-item>

<!-- Textarea in an item with a floating label -->
<ion-item>
  <ion-label position="floating">Description</ion-label>
  <ion-textarea></ion-textarea>
</ion-item>

<!-- Disabled and readonly textarea in an item with a stacked label -->
<ion-item>
  <ion-label position="stacked">Summary</ion-label>
  <ion-textarea
    disabled
    readonly
    value="Ionic enables developers to build performant, high-quality mobile apps.">
  </ion-textarea>
</ion-item>

<!-- Textarea that clears the value on edit -->
<ion-item>
  <ion-label>Comment</ion-label>
  <ion-textarea clearOnEdit="true"></ion-textarea>
</ion-item>

<!-- Textarea with custom number of rows and cols -->
<ion-item>
  <ion-label>Notes</ion-label>
  <ion-textarea rows="6" cols="20" placeholder="Enter any notes here..."></ion-textarea>
</ion-item>

<!-- Default textarea -->
<ion-textarea></ion-textarea>

<!-- Textarea in an item with a placeholder -->
<ion-item>
  <ion-textarea placeholder="Enter more information here..."></ion-textarea>
</ion-item>

<!-- Textarea in an item with a floating label -->
<ion-item>
  <ion-label position="floating">Description</ion-label>
  <ion-textarea></ion-textarea>
</ion-item>

<!-- Disabled and readonly textarea in an item with a stacked label -->
<ion-item>
  <ion-label position="stacked">Summary</ion-label>
  <ion-textarea
    disabled
    readonly
    value="Ionic enables developers to build performant, high-quality mobile apps.">
  </ion-textarea>
</ion-item>

<!-- Textarea that clears the value on edit -->
<ion-item>
  <ion-label>Comment</ion-label>
  <ion-textarea clear-on-edit="true"></ion-textarea>
</ion-item>

<!-- Textarea with custom number of rows and cols -->
<ion-item>
  <ion-label>Notes</ion-label>
  <ion-textarea rows="6" cols="20" placeholder="Enter any notes here..."></ion-textarea>
</ion-item>

import React, { useState } from 'react';
import { IonContent, IonHeader, IonPage, IonTitle, IonToolbar, IonTextarea, IonItem, IonLabel, IonItemDivider, IonList } from '@ionic/react';

export const TextAreaExamples: React.FC = () => {
  const [text, setText] = useState<string>();

  return (
    <IonPage>
      <IonHeader>
        <IonToolbar>
          <IonTitle>TextArea Examples</IonTitle>
        </IonToolbar>
      </IonHeader>
      <IonContent>
        <IonList>
          <IonItemDivider>Default textarea</IonItemDivider>          
          <IonItem>
            <IonTextarea value={text} onIonChange={e => setText(e.detail.value!)}></IonTextarea>
          </IonItem>

          <IonItemDivider>Textarea in an item with a placeholder</IonItemDivider>
          <IonItem>
            <IonTextarea placeholder="Enter more information here..." value={text} onIonChange={e => setText(e.detail.value!)}></IonTextarea>
          </IonItem>

          <IonItemDivider>Textarea in an item with a floating label</IonItemDivider>
          <IonItem>
            <IonLabel position="floating">Description</IonLabel>
            <IonTextarea value={text} onIonChange={e => setText(e.detail.value!)}></IonTextarea>
          </IonItem>

          <IonItemDivider>Disabled and readonly textarea in an item with a stacked label</IonItemDivider>
          <IonItem>
            <IonLabel position="stacked">Summary</IonLabel>
            <IonTextarea
              disabled
              readonly
              value={text} onIonChange={e => setText(e.detail.value!)}>
            </IonTextarea>
          </IonItem>

          <IonItemDivider>Textarea that clears the value on edit</IonItemDivider>
          <IonItem>
            <IonLabel>Comment</IonLabel>
            <IonTextarea clearOnEdit={true} value={text} onIonChange={e => setText(e.detail.value!)}></IonTextarea>
          </IonItem>

          <IonItemDivider>Textarea with custom number of rows and cols</IonItemDivider>
          <IonItem>
            <IonLabel>Notes</IonLabel>
            <IonTextarea rows={6} cols={20} placeholder="Enter any notes here..." value={text} onIonChange={e => setText(e.detail.value!)}></IonTextarea>
          </IonItem>
        </IonList>
      </IonContent>
    </IonPage>
  );
};

import { Component, h } from '@stencil/core';

@Component({
  tag: 'textarea-example',
  styleUrl: 'textarea-example.css'
})
export class TextareaExample {
  render() {
    return [
      // Default textarea
      <ion-textarea></ion-textarea>,

      // Textarea in an item with a placeholder
      <ion-item>
        <ion-textarea placeholder="Enter more information here..."></ion-textarea>
      </ion-item>,

      // Textarea in an item with a floating label
      <ion-item>
        <ion-label position="floating">Description</ion-label>
        <ion-textarea></ion-textarea>
      </ion-item>,

      // Disabled and readonly textarea in an item with a stacked label
      <ion-item>
        <ion-label position="stacked">Summary</ion-label>
        <ion-textarea
          disabled
          readonly
          value="Ionic enables developers to build performant, high-quality mobile apps.">
        </ion-textarea>
      </ion-item>,

      // Textarea that clears the value on edit
      <ion-item>
        <ion-label>Comment</ion-label>
        <ion-textarea clearOnEdit={true}></ion-textarea>
      </ion-item>,

      // Textarea with custom number of rows and cols
      <ion-item>
        <ion-label>Notes</ion-label>
        <ion-textarea rows={6} cols={20} placeholder="Enter any notes here..."></ion-textarea>
      </ion-item>
    ];
  }
}

<template>
  <!-- Default textarea -->
  <ion-textarea></ion-textarea>

  <!-- Textarea in an item with a placeholder -->
  <ion-item>
    <ion-textarea placeholder="Enter more information here..."></ion-textarea>
  </ion-item>

  <!-- Textarea in an item with a floating label -->
  <ion-item>
    <ion-label position="floating">Description</ion-label>
    <ion-textarea></ion-textarea>
  </ion-item>

  <!-- Disabled and readonly textarea in an item with a stacked label -->
  <ion-item>
    <ion-label position="stacked">Summary</ion-label>
    <ion-textarea
      disabled
      readonly
      value="Ionic enables developers to build performant, high-quality mobile apps.">
    </ion-textarea>
  </ion-item>

  <!-- Textarea that clears the value on edit -->
  <ion-item>
    <ion-label>Comment</ion-label>
    <ion-textarea clear-on-edit="true"></ion-textarea>
  </ion-item>

  <!-- Textarea with custom number of rows and cols -->
  <ion-item>
    <ion-label>Notes</ion-label>
    <ion-textarea rows="6" cols="20" placeholder="Enter any notes here..."></ion-textarea>
  </ion-item>
</template>

<script>
import { IonItem, IonLabel, IonTextarea } from '@ionic/vue';
import { defineComponent } from 'vue';

export default defineComponent({
  components: { IonItem, IonLabel, IonTextarea }
});
</script>

Prorerties

autoGrow
Description	If true, the element height will increase based on the value.
Attribute	auto-grow
Type	boolean
Default	false
autocapitalize
Description	Indicates whether and how the text value should be automatically capitalized as it is entered/edited by the user.
Attribute	autocapitalize
Type	string
Default	'none'
autofocus
Description	This Boolean attribute lets you specify that a form control should have input focus when the page loads.
Attribute	autofocus
Type	boolean
Default	false
clearOnEdit
Description	If true, the value will be cleared after focus upon edit. Defaults to true when type is "password", false for all other types.
Attribute	clear-on-edit
Type	boolean
Default	false
color
Description	The color to use from your application's color palette. Default options are: "primary", "secondary", "tertiary", "success", "warning", "danger", "light", "medium", and "dark". For more information on colors, see theming.
Attribute	color
Type	string | undefined
cols
Description	The visible width of the text control, in average character widths. If it is specified, it must be a positive integer.
Attribute	cols
Type	number | undefined
debounce
Description	Set the amount of time, in milliseconds, to wait to trigger the ionChange event after each keystroke. This also impacts form bindings such as ngModel or v-model.
Attribute	debounce
Type	number
Default	0
disabled
Description	If true, the user cannot interact with the textarea.
Attribute	disabled
Type	boolean
Default	false
enterkeyhint
Description	A hint to the browser for which enter key to display. Possible values: "enter", "done", "go", "next", "previous", "search", and "send".
Attribute	enterkeyhint
Type	"done" | "enter" | "go" | "next" | "previous" | "search" | "send" | undefined
inputmode
Description	A hint to the browser for which keyboard to display. Possible values: "none", "text", "tel", "url", "email", "numeric", "decimal", and "search".
Attribute	inputmode
Type	"decimal" | "email" | "none" | "numeric" | "search" | "tel" | "text" | "url" | undefined
maxlength
Description	If the value of the type attribute is text, email, search, password, tel, or url, this attribute specifies the maximum number of characters that the user can enter.
Attribute	maxlength
Type	number | undefined
minlength
Description	If the value of the type attribute is text, email, search, password, tel, or url, this attribute specifies the minimum number of characters that the user can enter.
Attribute	minlength
Type	number | undefined
mode
Description	The mode determines which platform styles to use.
Attribute	mode
Type	"ios" | "md"
name
Description	The name of the control, which is submitted with the form data.
Attribute	name
Type	string
Default	this.inputId
placeholder
Description	Instructional text that shows before the input has a value.
Attribute	placeholder
Type	null | string | undefined
readonly
Description	If true, the user cannot modify the value.
Attribute	readonly
Type	boolean
Default	false
required
Description	If true, the user must fill in a value before submitting a form.
Attribute	required
Type	boolean
Default	false
rows
Description	The number of visible text lines for the control.
Attribute	rows
Type	number | undefined
spellcheck
Description	If true, the element will have its spelling and grammar checked.
Attribute	spellcheck
Type	boolean
Default	false
value
Description	The value of the textarea.
Attribute	value
Type	null | string | undefined
Default	''
wrap
Description	Indicates how the control wraps text.
Attribute	wrap
Type	"hard" | "off" | "soft" | undefined

Events

Name	Description
ionBlur	Emitted when the input loses focus.
ionChange	Emitted when the input value has changed.
ionFocus	Emitted when the input has focus.
ionInput	Emitted when a keyboard input occurred.

Methods

getInputElement
Description	Returns the native <textarea> element used under the hood.
Signature	getInputElement() => Promise<HTMLTextAreaElement>
setFocus
Description	Sets focus on the native textarea in ion-textarea. Use this method instead of the global textarea.focus().
Signature	setFocus() => Promise<void>

Css Custom Properties

Name	Description
--background	Background of the textarea
--border-radius	Border radius of the textarea
--color	Color of the text
--padding-bottom	Bottom padding of the textarea
--padding-end	Right padding if direction is left-to-right, and left padding if direction is right-to-left of the textarea
--padding-start	Left padding if direction is left-to-right, and right padding if direction is right-to-left of the textarea
--padding-top	Top padding of the textarea
--placeholder-color	Color of the placeholder text
--placeholder-font-style	Style of the placeholder text
--placeholder-font-weight	Weight of the placeholder text
--placeholder-opacity	Opacity of the placeholder text