375
votes

I've got the following HTML5 form: http://jsfiddle.net/nfgfP/

<form id="form" onsubmit="return(login())">
<input name="username" placeholder="Username" required />
<input name="pass"  type="password" placeholder="Password" required/>
<br/>Remember me: <input type="checkbox" name="remember" value="true" /><br/>
<input type="submit" name="submit" value="Log In"/>

Currently when I hit enter when they're both blank, a popup box appears saying "Please fill out this field". How would I change that default message to "This field cannot be left blank"?

EDIT: Also note that the type password field's error message is simply *****. To recreate this give the username a value and hit submit.

EDIT: I'm using Chrome 10 for testing. Please do the same

14
Oh, +1 for the insane empty-password validation message =/ How did that pass QA, I wonder...David says reinstate Monica
Why not just accept the browser default message? That's what users see for every other site they visit, you'll just confuse your users by creating a non-standard message. (Google has probably managed more UX evaluation & testing in determining that wording than you have!).ChrisV
@ChrisV What about multilanguage sites?inemanja
In my case I want to check that the value is a number before posting but I can't use the type="number" attribute (for reasons.) So I set the pattern attribute to check for numbers and optional decimals which gives the message, "Please match the requested format," on error. I'd rather it said, "Ye must gift us a number bucko."Kristopher

14 Answers

305
votes

Use setCustomValidity:

document.addEventListener("DOMContentLoaded", function() {
    var elements = document.getElementsByTagName("INPUT");
    for (var i = 0; i < elements.length; i++) {
        elements[i].oninvalid = function(e) {
            e.target.setCustomValidity("");
            if (!e.target.validity.valid) {
                e.target.setCustomValidity("This field cannot be left blank");
            }
        };
        elements[i].oninput = function(e) {
            e.target.setCustomValidity("");
        };
    }
})

I changed to vanilla JavaScript from Mootools as suggested by @itpastorn in the comments, but you should be able to work out the Mootools equivalent if necessary.

Edit

I've updated the code here as setCustomValidity works slightly differently to what I understood when I originally answered. If setCustomValidity is set to anything other than the empty string it will cause the field to be considered invalid; therefore you must clear it before testing validity, you can't just set it and forget.

Further edit

As pointed out in @thomasvdb's comment below, you need to clear the custom validity in some event outside of invalid otherwise there may be an extra pass through the oninvalid handler to clear it.

376
votes

Here is the code to handle custom error message in HTML5:

<input type="text" id="username" required placeholder="Enter Name"
  oninvalid="this.setCustomValidity('Enter User Name Here')"
  oninput="this.setCustomValidity('')"/>

This part is important because it hides the error message when the user inputs new data:

oninput="this.setCustomValidity('')"
105
votes

It's very simple to control custom messages with the help of HTML5 event oninvalid

Here is code:

<input id="UserID"  type="text" required="required"
       oninvalid="this.setCustomValidity('Witinnovation')"
       onvalid="this.setCustomValidity('')">

This is most important:

onvalid="this.setCustomValidity('')"
69
votes

Note: This no longer works in Chrome, not tested in other browsers. See edits below. This answer is being left here for historical reference.

If you feel that the validation string really should not be set by code, you can set you input element's title attribute to read "This field cannot be left blank". (Works in Chrome 10)

title="This field should not be left blank."

See http://jsfiddle.net/kaleb/nfgfP/8/

And in Firefox, you can add this attribute:

x-moz-errormessage="This field should not be left blank."

Edit

This seems to have changed since I originally wrote this answer. Now adding a title does not change the validity message, it just adds an addendum to the message. The fiddle above still applies.

Edit 2

Chrome now does nothing with the title attribute as of Chrome 51. I am not sure in which version this changed.

45
votes

It's very simple to control custom messages with the help of the HTML5 oninvalid event

Here is the code:

User ID 
<input id="UserID"  type="text" required 
       oninvalid="this.setCustomValidity('User ID is a must')">
45
votes

By setting and unsetting the setCustomValidity in the right time, the validation message will work flawlessly.

<input name="Username" required 
oninvalid="this.setCustomValidity('Username cannot be empty.')" 
onchange="this.setCustomValidity('')" type="text" />

I used onchange instead of oninput which is more general and occurs when the value is changed in any condition even through JavaScript.

41
votes

I have made a small library to ease changing and translating the error messages. You can even change the texts by error type which is currently not available using title in Chrome or x-moz-errormessage in Firefox. Go check it out on GitHub, and give feedback.

It's used like:

<input type="email" required data-errormessage-value-missing="Please input something">

There's a demo available at jsFiddle.

27
votes

Try this one, its better and tested:

HTML:

<form id="myform">
    <input id="email" 
           oninvalid="InvalidMsg(this);" 
           oninput="InvalidMsg(this);"
           name="email"  
           type="email" 
           required="required" />
    <input type="submit" />
</form>

JAVASCRIPT:

function InvalidMsg(textbox) {
    if (textbox.value === '') {
        textbox.setCustomValidity('Required email address');
    } else if (textbox.validity.typeMismatch){
        textbox.setCustomValidity('please enter a valid email address');
    } else {
       textbox.setCustomValidity('');
    }

    return true;
}

Demo:

http://jsfiddle.net/patelriki13/Sqq8e/

13
votes

The easiest and cleanest way I've found is to use a data attribute to store your custom error. Test the node for validity and handle the error by using some custom html. enter image description here

le javascript

if(node.validity.patternMismatch)
        {
            message = node.dataset.patternError;
        }

and some super HTML5

<input type="text" id="city" name="city" data-pattern-error="Please use only letters for your city." pattern="[A-z ']*" required>
7
votes

The solution for preventing Google Chrome error messages on input each symbol:

<p>Click the 'Submit' button with empty input field and you will see the custom error message. Then put "-" sign in the same input field.</p>
<form method="post" action="#">
  <label for="text_number_1">Here you will see browser's error validation message on input:</label><br>
  <input id="test_number_1" type="number" min="0" required="true"
         oninput="this.setCustomValidity('')"
         oninvalid="this.setCustomValidity('This is my custom message.')"/>
  <input type="submit"/>
</form>

<form method="post" action="#">
  <p></p>
  <label for="text_number_1">Here you will see no error messages on input:</label><br>
  <input id="test_number_2" type="number" min="0" required="true"
         oninput="(function(e){e.setCustomValidity(''); return !e.validity.valid && e.setCustomValidity(' ')})(this)"
         oninvalid="this.setCustomValidity('This is my custom message.')"/>
  <input type="submit"/>
</form>
5
votes

I have a simpler vanilla js only solution:

For checkboxes:

document.getElementById("id").oninvalid = function () {
    this.setCustomValidity(this.checked ? '' : 'My message');
};

For inputs:

document.getElementById("id").oninvalid = function () {
    this.setCustomValidity(this.value ? '' : 'My message');
};
2
votes

Okay, oninvalid works well but it shows error even if user entered valid data. So I have used below to tackle it, hope it will work for you as well,

oninvalid="this.setCustomValidity('Your custom message.')" onkeyup="setCustomValidity('')"

1
votes

Adapting Salar's answer to JSX and React, I noticed that React Select doesn't behave just like an <input/> field regarding validation. Apparently, several workarounds are needed to show only the custom message and to keep it from showing at inconvenient times.

I've raised an issue here, if it helps anything. Here is a CodeSandbox with a working example, and the most important code there is reproduced here:

Hello.js

import React, { Component } from "react";
import SelectValid from "./SelectValid";

export default class Hello extends Component {
  render() {
    return (
      <form>
        <SelectValid placeholder="this one is optional" />
        <SelectValid placeholder="this one is required" required />
        <input
          required
          defaultValue="foo"
          onChange={e => e.target.setCustomValidity("")}
          onInvalid={e => e.target.setCustomValidity("foo")}
        />
        <button>button</button>
      </form>
    );
  }
}

SelectValid.js

import React, { Component } from "react";
import Select from "react-select";
import "react-select/dist/react-select.css";

export default class SelectValid extends Component {
  render() {
    this.required = !this.props.required
      ? false
      : this.state && this.state.value ? false : true;
    let inputProps = undefined;
    let onInputChange = undefined;
    if (this.props.required) {
      inputProps = {
        onInvalid: e => e.target.setCustomValidity(this.required ? "foo" : "")
      };
      onInputChange = value => {
        this.selectComponent.input.input.setCustomValidity(
          value
            ? ""
            : this.required
              ? "foo"
              : this.selectComponent.props.value ? "" : "foo"
        );
        return value;
      };
    }
    return (
      <Select
        onChange={value => {
          this.required = !this.props.required ? false : value ? false : true;
          let state = this && this.state ? this.state : { value: null };
          state.value = value;
          this.setState(state);
          if (this.props.onChange) {
            this.props.onChange();
          }
        }}
        value={this && this.state ? this.state.value : null}
        options={[{ label: "yes", value: 1 }, { label: "no", value: 0 }]}
        placeholder={this.props.placeholder}
        required={this.required}
        clearable
        searchable
        inputProps={inputProps}
        ref={input => (this.selectComponent = input)}
        onInputChange={onInputChange}
      />
    );
  }
}
-10
votes

Can be easily handled by just putting 'title' with the field:

<input type="text" id="username" required title="This field can not be empty"  />