Html code for validating forms
In tandem with the new input types and attributes provided by HTML5, CSS3 gives us some new pseudo-classes we can use to provide visual clues to the user as to which form fields are required, which are optional, and which contain validation errors.
Required fields can use the Now, in addition to showing the help text when the input field receives focus, we'll also show the help text when the input field's value is invalid.
Finally we covered how to disable HTML form validation, and detect whether form validation was available or not in case we have to support browsers that are yet to support this feature.
Let me know what you think of all this in the comments.
You can even run the validation code on the backend (if you're using Node) and show the error in the form without wiring all of the fields up manually.
By using Field Val UI to build a form and then Field Val to validate the input, you can pass the error straight back into the form.
One option is to not do anything and rely on your server-side validation only.
This would require no extra work on your part, but would the UX for those using unsupported browsers be satisfactory?
We'll want the 'Name' field to be submitted in the format 'Firstname Lastname', and to only contain letters and a space (NB in real world scenarios, you might need to take account of other locales – this example has been kept simple deliberately).But the great thing about them is that they all degrade gracefully.So if an older browser doesn't support them, the fact that they're in the HTML won't 'break' anything, they’ll just be rendered as an .After making all these changes our HTML now looks like this: https://jsfiddle.net/ianoxley/9C2JD/ The good news is that HTML form validation is supported by all the latest desktop browsers, and most mobile browsers.The bad news is that it is only partially supported in Safari, and isn't supported at all on i OS Safari, or the default Android browser.