Angular Validator - PatternRule

A validation rule that requires that the validated field match a specified pattern.

import { PatternRule } from "devextreme/common"
Type:

Object

To specify the regular expression that the validated field must match, set the rule's pattern configuration property.

View Demo

NOTE
If you apply a pattern rule to a DateBox component, specify dateSerializationFormat so that the format of the validated value is a string.
See Also

ignoreEmptyValue

If set to true, empty values are valid.

Type:

Boolean

Default Value: true

message

Specifies the message that is shown if the rule is broken.

Type:

String

Default Value: 'Value does not match pattern'

An error message can be specified as follows:

  • Hard-code the message

    App.js
    • import React from 'react';
    •  
    • import 'devextreme/dist/css/dx.light.css';
    •  
    • import { TextBox } from 'devextreme-react/text-box';
    • import {
    • Validator,
    • PatternRule
    • } from 'devextreme-react/validator';
    •  
    • class App extends React.Component {
    • render() {
    • return (
    • <TextBox>
    • <Validator>
    • <PatternRule
    • message="My custom message" />
    • </Validator>
    • </TextBox>
    • );
    • }
    • }
    • export default App;
  • Hide the message

    App.js
    • import React from 'react';
    •  
    • import 'devextreme/dist/css/dx.light.css';
    •  
    • import { TextBox } from 'devextreme-react/text-box';
    • import {
    • Validator,
    • PatternRule
    • } from 'devextreme-react/validator';
    •  
    • class App extends React.Component {
    • render() {
    • return (
    • <TextBox>
    • <Validator>
    • <PatternRule
    • message="" />
    • </Validator>
    • </TextBox>
    • );
    • }
    • }
    • export default App;
  • Display the editor's name in the message

    App.js
    • import React from 'react';
    •  
    • import 'devextreme/dist/css/dx.light.css';
    •  
    • import { TextBox } from 'devextreme-react/text-box';
    • import {
    • Validator,
    • PatternRule
    • } from 'devextreme-react/validator';
    •  
    • class App extends React.Component {
    • render() {
    • return (
    • <TextBox>
    • {/* The error message will be "Phone number does not match pattern" */}
    • <Validator name="Phone number">
    • <PatternRule} />
    • </Validator>
    • </TextBox>
    • );
    • }
    • }
    •  
    • export default App;

pattern

Specifies the regular expression that the validated value must match.

Type:

RegExp

|

String

NOTE

If your pattern is a string, escape the backslash. For example, the following pattern matches a character other than white space:

  • pattern: '\\S'

type

Specifies the rule type. Set it to "pattern" to use the PatternRule.