Providing validations to HTML Form

[Praveen Kumar]

Hi, 

I am new to Dart language , I would like to know how to provide validations to the HTML Form just like we provide using JavaScripts.

For instance:

<form name='registration' onSubmit="return formValidation();">

<ul>

<li><label for="userid">User id:</label></li>

<li><input type="text" name="userid" size="12" /></li>

<li><label for="passid">Password:</label></li>

<li><input type="password" name="passid" size="12" /></li>

<li><input type="submit" name="submit" value="Submit" /></li>

</ul>

</form>

In JavaScript we do as following

function formValidation()

{

var uid = document.registration.userid;

var passid = document.registration.passid;

if(userid_validation(uid,5,12))

{

if(passid_validation(passid,7,12))

{

}

}

return false;

function userid_validation(uid,mx,my)

{

var uid_len = uid.value.length;

if (uid_len == 0 || uid_len >= my || uid_len < mx)

{

alert("User Id should not be empty / length be between "+mx+" to "+my);

uid.focus();

return false;

}

return true;

}

function passid_validation(passid,mx,my)

{

var passid_len = passid.value.length;

if (passid_len == 0 ||passid_len >= my || passid_len < mx)

{

alert("Password should not be empty / length be between "+mx+" to "+my);

passid.focus();

return false;

}

return true;

alert('Form Succesfully Submitted');

}

how to this in dart ?

[Bob Nystrom]

In most cases, the way you accomplish something in JS is the same or nearly the same to what you would write in Dart.

Skimming your code, the main differences I can think of are:

• In Dart, you'll do window.alert() instead of just alert().
• To get the form element, you'll do (I think) query('registration') instead of window.registration.

Try that and if it doesn't work, let us know what problems you run into.

Cheers!

- bob

--
Consider asking HOWTO questions at Stack Overflow: http://stackoverflow.com/tags/dart
 
 

[John Evans]

I think it might be this Bob:

document.query('[name="registration"]')

From: http://synonym.dartlang.org/  :)