I'm pretty new to Play Framework.
My problem is that when a user clicks on the register link, he will instantly see validation errors.
The problem is that the method that serves the form also validates the form. So when the user clicks on the register link, gets to the validation without any input and then gets validation errors.
One solution would be to have an extra method to only serve the register form. But this would require an extra form and an extra route.
Another solution would be to disable validation on empty forms.
Is this possible? If not is there an other way?
You are on the way to a good solution. Make a second method.
GET /register controllers.RegistrationController.showRegistration()
POST /register controllers.RegistrationController.register()
The first is to display the registration page with the form, the latter to handle the form submit.
A method should stick to do one thing: either to show a registration page or to handle a post. Generally it's not a good idea to write a single method with a lots of if-then-else flow control statements.
Play framework also supports REST principles: in a simplified way GET is to retrieve a resource (=an empty registration page here), POST is to submit data(=do the registration).
Have a good look at Play framework's examples, I think the computer-database is very simple and a good starting point for you.
Related
Whatsup guys
I am struggling with an issue which is displaying errors on appended inputs in a form after submit. I guess there is a simple solution on this which i dont know of because i am a newbie in Laravel.
Scenario:
I have a form where a user needs to select a category and depending on the selection, a few inputs should be appended (with ajax) into the same form below the category dropdown. I have set up the validations and the error rendering on the html but it doesnt seem to work yet the request doesnt pass since it detects the validations.
Any clues?
You will not be able to display the errors next to form inputs that have been retrieved with Ajax. However, you may use an error box at the top of the screen describing the problem. Or you may simply post the form using Ajax instead of a page refresh, then using JavaScript, you can display the errors to the appended input.
If this is not an answer to the question you are asking, please provide code and more details.
I trying to add some fields to form depending of checkbox. But I have no idea how can I do that. I think Ajax can be useful, but I dont work with Ajax in Symfony2 yet, and if my form build up not in the controller what value I need specify in url: option of Ajax?
That's quite a broad question, but essentially: the Symfony way is to add them to the Form in the Controller by reacting to FormEvents.
Symfony Docs on Form Events
One way to achieve what you're after is to submit the form twice - the first time code will react to the checked checkbox and arrange the rest of the form as required, the second time the form will be valid and you can take action. Details on the above link. AJAX might help with this, allowing a form submission as soon as you've checked the checkbox.
Although you can create HTML form fields using AJAX, when you submit the form those fields need to exist in the Form object. You can add them just in time, in the controller, before Symfony tries to bind them.
My angular application needs to submit a form to a vendor. They then redirect the user to a page that I specified earlier in the process.
So I want standard, non-angular html form submit behaviour.
The documentation (details below) makes it sound like all I need to do is add an action attribute to my form element. I have tried this and it does not work.
Has anyone used this functionality in angular? Is there another step that I am missing?
The relevant section of the documentation at https://docs.angularjs.org/api/ng/directive/form is:
Submitting a form and preventing the default action
Since the role of forms in client-side Angular applications is different than in classical roundtrip apps, it is desirable for the browser not to translate the form submission into a full page reload that sends the data to the server. Instead some javascript logic should be triggered to handle the form submission in an application-specific way.
For this reason, Angular prevents the default action (form submission to the server) unless the element has an action attribute specified.
Angular does that. When you provide an action on the form, it should do exactly what you're trying to do (do a javascript thing, then submit the form).
Here is a plunk
In the plunk, you can see the $scope.submitted say 'submitted' just before the form submission kicks the page over to the submitted.html
I have a textarea that I first print some values coming from a request.getParameter("some_textarea_name"). The user is allowed to modify those values and then I want to get the new values and replace the old ones with the new ones so as to query the new ones and get the results from my database tables. Can I do that without redirecting the user to a new page e.g without using the <form method> and the request.getParameter()
Can I do that without redirecting the user
Yes, you can implement an ajax call that will submit the form without redirecting the user and you can do something with the response (perhaps add it to the page).
If you need help using ajax follow this tutorial, but be aware that it implements AJAX in pure javascript (its a bit more bloated / complicated). If you want to keep it simple look into jQuery ajax, and here is a tutorial too.
without using the
No, you need to use the form to be submitted, however if you use ajax you wont need to redirect the user.
I have a jsp form which takes in user details. On submit button it goes to a jsp page where the details are entered into the database. But before that I would like to check if the username is available as soon as the user clicks the check availability button. How can this be done?
2 ways:
Just redisplay the same page after submitting the form wherein you conditionally display the validation message. This is rather trivial and already covered in the Hello World example in our Servlets wiki page.
Use Ajax to send an asynchronous HTTP request and manipulate the HTML DOM based on the response of the request. This requires a bit more in depth understanding of how websites really work and what JavaScript is. You can find some concrete examples in How to use Servlets and Ajax?
Use AJAX(Asynchronous Javascript and Xml). Its the best web2.0 technology. You can manipulate DOM based on the answer from server