Question

I have a form and a submit button. I would like to put a condition with jquery on this submit button. I wan’t it to post the form only if the user enters a valid email adress.

HTML code :

<form  method="post" action="{% url sportdub.views.login %}">
    <input type="text" name="email" value="" class="span8"/>
    <input type="submit"></button>
</form>

Javascript code :

function isValidEmailAddress(emailAddress) {
    var pattern = new RegExp(/^((([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+(\.([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+)*)|((\x22)((((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(([\x01-\x08\x0b\x0c\x0e-\x1f\x7f]|\x21|[\x23-\x5b]|[\x5d-\x7e]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(\\([\x01-\x09\x0b\x0c\x0d-\x7f]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))))*(((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(\x22)))@((([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.)+(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.?$/i);
    return pattern.test(emailAddress);
};

What I want to do is to put a condition on my submit button:

if( !isValidEmailAddress( emailaddress ) ) { 
    /* don't submit the form and raise an error */ 
} else { 
    /* submit the form */
}

Any idea on how I could accomplish that?

Answer 1

You need to add onsubmit event handler to your form and return false if it don’t pass validation.

For example according to your code:

  <form  method="post" action="{% url sportdub.views.login %}" onsubmit="return validateForm();">
    <input type="text" id="formEmail" name="email" value="" class="span8"/>
    <input type="submit"></button>
  </form>

in JS:

function validateForm() {
    if( !isValidEmailAddress( document.getElementById( 'formEmail' ).value ) ) { 
        // also before return you can add alert( 'your e-mail is invalid' ); 
        // or display message in form, etc...
        return false;
     } else { 
        return true;
     }    
}

Btw, I would not recommend to use inline JS attributes, just add to all your elements and to form unique id attribute and if you use jQuery you can do all validations in .submit() method.