I'm looking for a way to validate a single field at a time. This is so, while a user is filling in a form, each time the keypress or blur event occurs for each field, i can validate that field individually and show / hide its error message.
Is that possible? If so, how can I do it? Some google searching hasn't turned up any results which validate a single field, rather than the whole form.
You can use javax.validation.Validator#validateProperty() for that purpose.
I'd recommend that you try using Javascript Regular Expressions to validate user inputs and show/hide error messages. I provided a code implementation example in the post at this link: Example using Regular Expresssions
Add an event listener to relevant input field in the DOM to provide responsiveness.
var letterField = document.getElementById('letterField'); // DOM element containing user input
letterField.addEventListener('keyup', function() { // key press event listener using anonymous function
if (event.keyCode === 13) { // run this code if the 'enter' key is pressed
if ( ... ) {
...
};
};
};
If you want to add effects, include the following code to transition the error message. Refer to the jQuery API for other effects:
userInputError.delay(800).fadeOut();
