In my web page I have a form that is being filled with data after some ajax requests. For example when a user chooses an item from the list, a simple ajax request is sent to the database that the item has been selected (but not confirmed, yet). Then the list on the web page reloads using a simpe ajax request (just the list, not the whole page) to fetch the new item list.
I think this is more or less a classic cart implementation.
However, when the user presses submit (classic form POST submit, not ajax POST for some reasons concerning the implementation) to confirm the whole list, I would like to return to the current page. (Current page varies) Is this possible? I am using django.
Thanks.
You can supply a next GET parameter when submitting the form, similar to django.contrib.auth's login() method:
https://docs.djangoproject.com/en/dev/topics/auth/#django.contrib.auth.views.login:
<form action="/url/to/post/form/?next={{ some_variable }}">
where the variable can simply be the current URL (taken from the request) or a generated URL. In the view processing the form, simply check for a next parameter and redirect appropriately:
from django.shortcuts import redirect
if 'next' in request.GET:
return redirect(request.GET['next'])
You may be able to use the Post/Redirect/Get Design pattern (PRG). For more general information about Post/Redirect/Get please see the following: http://en.wikipedia.org/wiki/Post/Redirect/Get There are some nice process flow diagrams there.
A generic example of a view implementing PRG might look like the following:
# urls.py
urlpatterns = patterns('',
url(r'^/$', views.my_view, name='named_url'),
)
# forms.py
class MyForm(forms.Form):
pass # the form
# views.py
def my_view(request, template_name='template.html'):
""" Example PostRedirectGet
This example uses a request context, but isn't
necessary for the PRG
"""
if request.POST:
form = MyForm(request.POST)
if form.is_valid():
try:
form.save()
# on success, the request is redirected as a GET
return HttpResponseRedirect(reverse('named_url'))
except:
pass # handling can go here
else:
form = MyForm()
return render_to_response(template_name, {
'form':form
}, context_instance=RequestContext(request))
If you need to do something more interesting with the GET, reverse can take args and kwargs. Manipulate the view params, url_pattern, and reverse call to display the results you would like to see.
One additional note is that you don't have to redirect to the same view (as this example does). It could be any named view that you would like to redirect the user to.
current page is a very vague term but i am assuming you want the page that referred you to the form page, this is normally (not always) stored in the HTTP_REFERRER header of the request itself. You could try to fetch that from the request and do a redirect.
Related
Let me tel the scenario where I am stuck, I will try to explain simply rather than telling the actual.
1st : I am on page 1. Where few subjects are there with unique names.
2nd : I will click on one subject, which will call an struts2 action (lets call it ActionA)at back end with the unique subject name as a request parameter(Request type = GET).
3rd : Action A will only redirect to "Tutorial page".
4th : While loading it will make an AJAX call to another Struts2 action (lets call it ActionB), which will return JSON containing tutorials for that Subject.
Problem: As I am calling ActionA first and passing the subject name which is just redirecting the page to some other page. On page load I am calling another action to get the JSON. I am not able to get the request parameter value at ActionB that is the one which is returning JSON.
Note: I am using Struts2-JSON plugin thats why not need two actions, one for redirecting the page another for getting the JSON at page load.
Solution tried: I have tried to get the request parameter value that is the Subject name, putting a hidden field in the Tutorial page. But unable to get the value from inside the Angular JS controller.
Here is the example for a shared Service: http://plnkr.co/edit/P2ItVj20RYCJVjdIaXfY
But you are right if you reload the page this doesn't work. I think your scenario needs tweaking if you want to use angular or any other single page framework for that matter. One purpose of single page applications is to minimize reloads, preferable none. If your action A only returns a template where you then want to input the result of action B, I recommend looking at ngRoute or uiRouter, where you define a template (result of action A) and a controller for that view. This template than replaces a section of your page (ng-view) with the new template. If both are new to you I would recommend looking at uiRouter, it is similar but it gives you a lot more possibilities. Both provide a "resolve" function where you can load your action B before the page is rendered.
Code from plunker
angular.module("app", [])
.controller("MainController", ['SharedService', function(SharedService) {
var vm = this;
//bind to service
vm.service = SharedService;
}]);
Service
angular.module("app")
.factory("SharedService", [function() {
var service = {
id: "test"
}
return service;
}]);
I have a register page with the usual email,name,password ..which is validated in the server's submitted route/page. if it fails then I redirect back but I want to fill the values back in the register page..I can put the register form parameters in the session but it will stay there...is there a page memory(a smaller scope than session) just like session which will be just for the next page and then gone/ which is the best way to implement this.
Thanks
Why don't you just render the registration page from the POST route like this:
post '/register' do
#registration_data = params[:stuff] # store all your registration data
if info_validates # everything validates
redirect './user_home'
else # something fails validation
haml :register # or erb or whatever your template engine is
end
end
Then in your view, have it fill in #registration_data if it exists.
Also, you can clear session data with session.clear.
Ajax validation would be much easier. You just register an onclick event to your form submit button that makes a call to a page that returns a json status code with the error information or 200 for OK. If 200, then submit.
I have a tiny application in MVC 3.
In this tiny application, I want my URLs very clear and consistent.
There's just one controller with one action with one parameter.
If no value is provided (that is, / is requested by the browser), then a form is displayed to collect that single value. If a value is provided, a page is rendered.
The only route is this one:
routes.MapRoute(
"Default",
"{account}",
new { controller = "Main", action = "Index", account = UrlParameter.Optional }
);
This all works fine, but the account parameter never appears in the address line as a part of the URL. I can manually type test.com/some_account and it will work, but other than that, the account goes as a post parameter and therefore does not appear. And if I use FormMethods.Get in my form, I get ?account=whatever appended to the URL, which is also not what I want and which goes against my understanding. My understanding was that the MVC framework would try to use parameters set in the route, and only if not found, it would append them after the ?.
I've tried various flavours of setting the routes -- one route with a default parameter, or one route with a required parameter, or two routes (one with a required parameter and one without parameters); I've tried mixing HttpGet/HttpPost in all possible ways; I've tried using single action method with optional parameter string account = null and using two action methods (one with parameter, one without), but I simply can't get the thing appear in the URL.
I have also consulted the Steven Sanderson's book on MVC 3, but on the screenshots there are no parameters either (a details page for Kayak is displayed, but the URL in the address bar is htpp://localhost:XXXX/).
The only thing that definitely works and does what I want is
return RedirectToAction("Index", new { account = "whatever" });
But in order to do it, I have to first check the raw incoming URL and do not redirect if it already contains an account in it, otherwise it is an infinite loop. This seems way too strange and unnecessary.
What is the correct way to make account always appear as a part of the URL?
My understanding was that the MVC framework would try to use
parameters set in the route, and only if not found, it would append
them after the ?
Your understanding is not correct. ASP.NET MVC doesn't append anything. It's the client browser sending the form submission as defined in the HTML specification:
The method attribute of the FORM element specifies the HTTP method used
to send the form to the processing agent. This attribute may take two
values:
get: With the HTTP "get" method, the form data set is appended to the URI specified by the action attribute (with a question-mark ("?")
as separator) and this new URI is sent to the processing agent.
post: With the HTTP "post" method, the form data set is included in the body of the form and sent to the processing agent.
ASP.NET MVC routes are used to parse an incoming client HTTP request and redispatch it to the corresponding controller actions. They are also used by HTML helpers such as Html.ActionLink or Html.BeginForm to generate correct routes. It's just that for your specific scenario where you need to submit a user entered value as part of the url path (not query string) the HTML specification has nothing to offer you.
So, if you want to fight against the HTML specification you will have to use other tools: javascript. So you could use GET method and subscribe to the submit handler of the form and inside it manipulate the url so the value that was appended after the ? satisfy your requirements.
Don't think of this as ASP.NET MVC and routes and stuff. Think of it as a simple HTML page (which is what the browser sees of course) and start tackling the problem from that side. How would you in a simple HTML page achieve this?
We have an existing Django form that accepts GET requests to allow users to bookmark their resulting query parameters. The form contains many fields, most of which are required. The form uses semi-standard boilerplate for handling the request, substituting GET for POST:
if request.method == 'GET':
form = myForm(request.GET)
if form.isValid()
# Gather fields together into query.
else
form = myForm()
The problem is that the first time the form is loaded, there's nothing in the GET request to populate the required fields with, so most of the form lights up with 'missing field' errors.
Setting initial values doesn't work; apparently, the non-existent values in the GET request override them.
How can we avoid this? I'm pretty certain we're simply not processing things correctly, but I can't find an example of a form that handles GET requests. We want errors to show up if the user hits the "Submit" button while fields are blank or otherwise invalid, but don't want these errors showing up when the form is initially displayed.
The positional argument to the forms.Form subclass informs Django that you intend to process a form rather than just display a blank/default form. Your if request.method == 'GET' isn't making the distinction that you want because regular old web requests by typing a URL in a web browser or clicking a link are also GET requests, so request.method is equal to GET either way.
You need some differentiating mechanism such that you can tell the difference between a form display and a form process.
Ideas:
If your processing is done via. AJAX, you could use if request.is_ajax() as your conditional.
Alternatively, you could include a GET token that signifies that the request is processing. Under this example, first you'd need something in your form:
<input type="hidden" name="action" value="process_form" />
And then you can look for that value in your view:
if 'action' in request.GET and request.GET['action'] == 'process_form':
form = myForm(request.GET)
if form.is_valid():
# form processing code
else:
form = myForm()
I'll also give you the standard, boilerplate point that it's generally preferable not to use GET for form processing if you can help it (precisely because you run into difficulties like this since you're using an anomalous pattern), but if you have a use case where you really need it, then you really need it. You know your needs better than I do. :-)
If your clean page load doesn't have any non form GET params, you can differentiate between a clean page load and a form submit in your view. Instead of the usual
form = YourForm()
if request.POST:
you can do
if request.GET.items():
form = YourForm(request.GET)
if form.is_valid():
...
else:
form = YourForm()
If your clean page load could have other params (eg email link tracking params) you'll need to use the QueryDict methods to test if any of your form params are in the request.
request.GET is and empty dictionary when you first load a clean form. Once you have submitted the form, request.GET will be populated with your fields data, even if the fields contain only empty data.
My first question is this, which I posted as comment:
Why not just use request.POST and the standard way of processing form data?
After considering everything here, perhaps what you are looking for is a way of processing data in your query string to populate a form. You can do that without using request.GET as your form.data.
In my own views, I take advantage of a utility function I created to add initial data to the form from request.GET, but I am not going to share that function here. Here's the signature, though. initial_dict is typically request.GET. model_forms is either a single ModelForm or a list of ModelForm.
def process_initial_data(model_forms, initial_dict):
Nevertheless, I am able to process the form through the standard practice of using request.POST when the form is POSTed. And I don't have to pass around all kinds of information in the URL query string or modify it with JavaScript as the user enters information.
I have footer view that's included on all my pages which contains a form. I would like to be able to make use of CI's form validation library to validate the form. Is that possible?
Currently the form posts back to the current page using the PHP_SELF environment variable. I don't want to get it to post to a controller because when validation fails it loads the controller name in the address bar, which is not the desired behaviour.
Any suggestions gratefully received.
Thanks,
Gaz
One way, whilst far from ideal, would be to create a "contact" function in every controller. This could be in the form of a library/helper.
CI doesn't natively let you call one controller from another, although I believe there are extensions that enable this.
Another option would be an AJAX call instead, which would allow you to post to a generic controller, validate etc whilst remaining on the current page.
In this use case, I would definitely go for an AJAX call to a generic controller. This allows you to show errors even before submitting in the origin page.
Another way (slightly more complex), involves posting your form data to a generic controller method, passing it a hidden input containing the current URL.
The generic controller method handling your form can then redirect to the page on which the user submitted the form, passing it the validation errors or a success message using flash session variables: $this->session->set_flashdata('errors',validation_errors()) might do the trick (untested)
The good thing about this is that you can use the generic form-handling method for both the ajax case (suppressing the redirect) and the non-ajax case
AJAX would be best, just like everyone else says.
I would redirect the form to one function in one controller, you could make a controller just for the form itself. Then have a hidden value with the return URL. As far as errors go you could send them back with flashdata.
Just remember to never copy paste code, it a bad practice and guarantees bugs.
//make sure you load the proper model
if ($this->form_validation->run() == FALSE){
// invalid
$redirect = $this->input->post('url');
$this->session->set_flashdata('errors',validation_errors());
redirect($redirect);
} else {
/*
success, do what you want here
*/
redirect('send them where ever');
}