Retrieving POST data from jQuery in Django without a form - django

I am currently able to use the post method of jQuery to a view pointed by myurl
jQuery.post("/myurl", {'value1':value1, 'value2':value2,
'csrftoken': '{{ csrf_token }}'},
function(data) {
alert("Data Loaded: " + data);
});
However, I don't know how to retrieve the posted data inside the view without using a form:
def save_user_graph(request):
if request.method == 'POST':
return HttpResponse(request.POST.get('value1'),status=201)
returns None.

If save_user_graph is returning None, then request.method is not POST. If save_user_graph is returning an HttpResponse with the word 'None' in it, then value1 isn't being sent correctly. Can you clarify which is the case?
If you have chrome, try navigating to the page with the developer toolbar open. You can go to the 'console' tab and view the AJAX request and see what data was sent with it, to make sure that the data was sent correctly.
Similarly, if you have firefox and firebug, you can go to the page and watch the ajax request and check the post parameters.
Assuming that the javascript works, you'll want to log request.POST in save_user_graph. In a pinch, you can just print request.POST and, assuming you're using the django dev server, the output will be printed in the dev server output.
We'll need a bit more debugging info before we can give a better answer. :)

Related

Django redirect page does not update the view

I'm using the Django Framework on Google App Engine.
I have multiple forms on the same view, to submit to different URL.
Trouble is after I get a form submitted: even if the called method update the datastore and some data, the previous page (where the forms are put in) is not refreshed, showing the updated data.
I could solve this problem using jQuery or some javascrip framework, appending dinamically content returned by the server but, how to avoid it?
Suggestions?
Am I wrong somewhere?
A part of "secure.html" template
<form action="/addMatch" method="post">
{% csrf_token %}
{{ form.as_p }}
<input type="submit" value="Submit" />
</form>
Matches:
<br />
{% for m in matches%}
{{m.description}} ---> {{m.reward}}
{% endfor%}
the "/addMatch" URL view:
def addMatch(request):
form = MatchForm(request.POST)
if form.is_valid():
user = User.all().filter('facebookId =', int(request.session["pbusr"]))
m = Match(user=user.get(),description =form.cleaned_data["description"],reward=form.cleaned_data["reward"])
m.save()
return HttpResponseRedirect("/secure/")
else:
logging.info("Not valid")
return HttpResponseRedirect("/secure")
The view method whose seems not working:
#auth_check_is_admin
def secure(request):
model={}
user = User.all().filter('facebookId =', int(request.session["pbusr"]))
u = user.get()
if (u.facebookFanPageId is not None and not u.facebookFanPageId == ""):
model["fanPageName"] = u.facebookFanPageName
model["form"] = MatchForm()
model["matches"] = u.matches
else:
....
return render(request,"secure.html",model)
Francesco
Based on what you posted, it seems like you're redirecting properly and are having database consistency issues. One way to test this would be to look at the network tab in the Google Chrome developer tools:
Click on the menu icon in the upper right
Click on "Tools"
Click on "Developer Tools"
Click on "Network" in the thing that opened up at the bottom of the screen.
Now, there will be a new entry in the network tab for every request that your browser sends and every response it receives. If you click on a request, you can see the data that was sent and received. If you need to see requests across different pages, you might want to check the "Preserve log" box.
With the network tab open, go to your page and submit the form. By looking at the network tab, you should be able to tell whether or not your browser issued a new GET request to the same URL. If there is a new request for the same page but that request has the old content, then you have a datastore consistency issue. If there was NOT a new request that yielded a response with the data for the page, then you have a redirect issue.
If it turns out that you have a datastore consistency issue, then what's happening is the data is being stored, but the next request for that data might still get the old data. To make sure that doesn't happen, you need what's called "strong consistency."
In a normal App Engine project, you get strong consistency by putting entities in the same entity-group and using ancestor queries. I'm not certain of what database/datastore you're using for Django and how the different database layers interact with App Engine's consistency, so this could be wrong, but if you can give your users the right key and then fetch them from that key directly (rather than getting all users and filtering them by key), you might get strong consistency.

Getting checkbox value in flask

I'm trying to poll the state of checkboxes (this is done in JS every three seconds). This solution returns "None" (see code below); Both printouts (with 'args' and with 'form') return "None". I'm expecting True/False, depending on the checkbox's boolean state.
index.html:
{% extends "layout.html" %}
{% block content %}
<div id="results" class="container">{{data_load|safe}}</div>
<input id='testName' type='checkbox' value='Yes' name='testName'>
{% endblock %}
and the relevant flask app snippet:
#app.route('/', methods = ['GET', 'POST'])
def index():
return render_template('index.html', data_load=timertry())
#app.route('/_timertry', methods = ['GET', 'POST'])
def timertry():
print request.args.get('testName')
print request.form.get('testName')
return "some html going into 'results' div.."
The JavaScript polling function (adapted from here):
$(document).ready(function() {
$.ajaxSetup({cache : false});
setInterval(function() {
$('#results').load('/_timertry?' + document.location );
}, 3000); // milliseconds!
});
This should be simple enough, but none of the SO solutions I looked into (e.g., using jquery, adapting the flask/ajax example, etc.) worked.
EDIT: following mark's suggestion (including the javascript) and adding
print request.values in index.html returns (seen on the console in Aptana):
CombinedMultiDict([ImmutableMultiDict([]), ImmutableMultiDict([])])
Clearly, the request seems empty. The post request is logged (when checkbox is pressed) as:
127.0.0.1 - - [03/Oct/2013 00:11:44] "POST /index HTTP/1.1" 200 -
Any ideas here?
Your javascript does the following every three seconds...
$('#results').load('/_timertry?' + document.location);
In other words, you are using the jQuery load() function. The documentation for that function states that this will, in essence, call an HTTP get request to the URL you provide as the parameter (something like /_timertry?http://www.example.org. In other words, a GET request will be called to /timertry?http://www.example.org, which will be handled by Flask's timertry method.
When you have an HTTP form, and you click the "Submit" button, the browser does some magic to push all of the values to the server in the request. When you just do a simple AJAX request, none of that happens for you. Instead, you need to explicitly state what you want to be passed as data to the server (although there are plugins to help you with "post the values of an HTML form using AJAX").
So, because at no point did you do anything in your Javascript to retrieve the value of checkbox to include it into the AJAX request, the AJAX request has no values specifying that the checkbox was checked. You would need to have jQuery check if the box is checked...
var isChecked = $('#testName').is(':checked');
# Now do something with isChecked...
From what I can tell, however, you are sort of misusing HTTP: the load function will make a GET request, and you probably want something to happen as a request of the request. You probably want to make it do a POST request instead (see here and here). Also, you mentioned that you're looking for something to post when a value is changed. Putting this together, you can do something like this...
// Ensure that the function is called when the DOM is ready...
$(function() {
// Register an event that should be fired when the checkbox value is changed
$('#testName').change(function() {
var data = { isChecked : $(this).is(':checked') };
$.post('/', data);
});
})
In this case, we have an event that is called when a checkbox is checked, and that event causes us to make a POST request to the server.
I'm going to answer this question which was found in the comments of the question
"which becomes a question of how to submit a form without a 'submit' button.."
So it is very possible to submit a value when a user clicks on the button
{% block content %}
<form id="target" action="YourViewName">
<div id="results" class="container">{{ data_load|safe }}</div>
<input id='testName' type='checkbox' value='Yes' name='testName'>
</form>
{% endblock %}
$( "#results" ).click(function() {
$( "#target" ).submit();
});
If you want to stay on the same page, however, you're going to need to use an ajax call to pass the data back rather then use a standard submit, however This tutorial covers that topic fairly well. but a basic change to send the data back would look like
$( "#results" ).click(function() {
var request = $.ajax({
type: "POST",
url: "/YourViewName",
data: {'input_value':$('#testName').val()},
dataType: "html"
}).done(function(msg) {
// I don''t know what you want to do with a return value...
// or if you even want a return value
}
});
and the flask would look like
#app.route("/YourViewName")
def example():
list_name = request.args.get("input_value")
#if you don't want to change the web page just give a blank return
return ""

form submit jQuery mobile

I've gotten it into my head that mobile applications don't like form submits the same way html does, so I thought I'd better have a sanity check on Stackoverflow.
For example, instead of having <input type="submit"...>, it looks like I should now use <a data-role="button"...>
Q: Can I continue to use <input type="submit"...> for mobile applications?
The reason why I ask is because the action page has some logic, such as:
<cfif structKeyExists(form,"Save")>
jQuery Mobile, at least as of this writing, by default submits forms via AJAX using the method specified on the form being submitted. POST submissions will still be posted to the server in the background, so ColdFusion will still see the form variables that are passed in as usual. When a response is generated, jQuery Mobile will take the response and transition the view over to whatever HTML was returned. In my own testing you can continue to use a normal submit button as well. If you want a standard submission rather than an AJAX submission, add data-ajax="false" to the form tag.
If you want to programatically submit a form, set the data-ajax attribute for the form to false and then set an event handler for the submit event for the form:
<form data-ajax=false></form>
$(function () {
$('form').bind('submit', function (event) {
event.preventDefault();
$.post('path/to/server.file', $(this).serialize(), function (data) {
alert('Server Response: ' + data);
});
});
});

jquery-autocomplete does not work with my django app

I have a problem with the jquery-autocomplete pluging and my django script. I want an easy to use autocomplete plugin. And for what I see this (http://code.google.com/p/jquery-autocomplete/) one seems very usefull and easy. For the django part I use this (http://code.google.com/p/django-ajax-selects/) I modified it a little, because the out put looked a little bit weired to me. It had 2 '\n' for each new line, and there was no Content-Length Header in the response. First I thought this could be the problem, because all the online examples I found had them. But that was not the problem.
I have a very small test.html with the following body:
<body>
<form action="" method="post">
<p><label for="id_tag_list">Tag list:</label>
<input id="id_tag_list" name="tag_list" maxlength="200" type="text" /> </p>
<input type="submit" value="Submit" />
</form>
</body>
And this is the JQuery call to add autocomplete to the input.
function formatItem_tag_list(row) {
return row[2]
}
function formatResult_tag_list(row) {
return row[1]
}
$(document).ready(function(){
$("input[id='id_tag_list']").autocomplete({
url:'http://gladis.org/ajax/tag',
formatItem: formatItem_tag_list,
formatResult: formatResult_tag_list,
dataType:'text'
});
});
When I'm typing something inside the Textfield Firefox (firebug) and Chromium-browser indicates that ther is an ajax call but with no response. If I just copy the line into my browser, I can see the the response. (this issue is solved, it was a safety feature from ajax not to get data from another domain)
For example when I am typing Bi in the textfield, the url "http://gladis.org/ajax/tag?q=Bi&max... is generated. When you enter this in your browser you get this response:
4|Bier|Bier
43|Kolumbien|Kolumbien
33|Namibia|Namibia
Now my ajax call get the correct response, but there is still no list showing up with all the possible entries. I tried also to format the output, but this doesn't work either. I set brakepoints to the function and realized that they won't be called at all.
Here is a link to my minimum HTML file http://gladis.org/media/input.html
Has anybody an idea what i did wrong. I also uploaded all the files as a small zip at http://gladis.org/media/example.zip.
Thank you for your help!
[Edit]
here is the urls conf:
(r'^ajax/(?P<channel>[a-z]+)$', 'ajax_select.views.ajax_lookup'),
and the ajax lookup channel configuration
AJAX_LOOKUP_CHANNELS = {
# the simplest case, pass a DICT with the model and field to search against :
'tag' : dict(model='htags.Tag', search_field='text'),
}
and the view:
def ajax_lookup(request,channel):
""" this view supplies results for both foreign keys and many to many fields """
# it should come in as GET unless global $.ajaxSetup({type:"POST"}) has been set
# in which case we'll support POST
if request.method == "GET":
# we could also insist on an ajax request
if 'q' not in request.GET:
return HttpResponse('')
query = request.GET['q']
else:
if 'q' not in request.POST:
return HttpResponse('') # suspicious
query = request.POST['q']
lookup_channel = get_lookup(channel)
if query:
instances = lookup_channel.get_query(query,request)
else:
instances = []
results = []
for item in instances:
results.append(u"%s|%s|%s" % (item.pk,lookup_channel.format_item(item),lookup_channel.format_result(item)))
ret_string = "\n".join(results)
resp = HttpResponse(ret_string,mimetype="text/html")
resp['Content-Length'] = len(ret_string)
return resp
You probably need a trailing slash at the end of the URL.
Also, your jQuery selector is wrong. You don't need quotes within the square brackets. However, that selector is better written like this anyway:
$("input#id_tag_list")
or just
$("#id_tag_list")
Separate answer because I've just thought of another possibility: is your static page being served from the same domain as the Ajax call (gladis.org)? If not, the same-domain policy will prevent Ajax from being loaded.
As an aside, assuming your document.ready is in your Django template, it would be a good idea to utilize the {% url %} tag rather than hardcoding your URL.
$(document).ready(function(){
$("input[id='id_tag_list']").autocomplete({
url:'{% url my_tag_lookup %}',
dataType:'text'
});
});
This way the JS snippet will be rendered with the computed URL and your code will remain portable.
I found a solution, but well I still don't know why the first approach didn't worked out. I just switched to a different library. I choose http://bassistance.de/jquery-plugins/jquery-plugin-autocomplete/. This one is actually promoted by jQuery and it works ;)

Render to response to a redirected url in Django

In a form submission scenario, form is post to "/submit". I want to redirect user to "/sucess" on success and pass render some message to a template at new url. How to do this in Django? render_to_response doesn't do redirect and HttpResponseRedirect doesn't do template rendering.
The response from Daniel Roseman is potentially dangerous, opening your site to XSS vulnerabilities.
Make sure you strip html tags from whatever message is passed if you must do it this way.
A better way would be to redirect to /success/?msg=ok, and have in your view a dictionary:
{ 'ok': 'Your success message' }
If your success page needs a dynamic message, you need to pass it there somehow. You can either do this via GET parameters in the URL you are redirecting to - eg return HttpResponseRedirect('/success/?msg=My+success+message+here') - or by setting some values in the session, which the success view can pick up.
The best way to do what you want is:
In your view set the success message (or error message) as a dict. And use the render_to_response to display any template.
In your template you can verify if there is a message and if the message is an error message or a success message.
Some like this:
In your view:
if anyError:
dict = {"message" : {"error" : "The error message"}}
else:
dict = {"message" : {"success" :"The success message"}}
in your template:
{% if message %}
{% if message.error %}
{{ message.error }}
{% else %}
{{ message.success }}
{% endif %}
{% endif %}
Hope i've helped
There is no good way to do what you want. The browser submits the form, which will take the user to /submit. Once you decide whether it's "successful", it's too late; the browser has already decided on it's destination. All you can do is redirect. But, as you're finding out, it's going to be hard to keep your POST state when you redirect.
I would give up on this. It's not how websites are supposed to work.
I think Django does this already if you extend the generic view. On create there's an optional argument "post_save_redirect". This functionality is used in the automatically generated Django admin system. For example if you want a new resource, say user, you go to the url "/user/add". After you submit it redirects you to "/user/1" with a success message "you just saved user #1". So this is possible, but I'm still researching how to do it without extending the generic view. I'm still very new to Django and python, so looking through Django core to find how they did it is not so easy for me.
I would recommend to use Django message framework which is used for one-time notification messages.
https://docs.djangoproject.com/en/1.8/ref/contrib/messages/