I am looking forward for posting some data and information on the web server through my iPhone application. I am not getting the way to post data to the web server from iPhone sdk.
It depends in what way you want to send data to the web server. If you want to just use the HTTP POST method, there are (at least) two options. You can use a synchronous or an asynchronous NSURLRequest. If you only want to post data and do not need to wait for a response from the server, I strongly recommend the asynchronous one, because it does not block the user interface. I.e. it runs "in the background" and the user can go on using (that is interacting with) your app. Asynchronous requests use delegation to tell the app that a request was sent, cancelled, completed, etc. You can also get the response via delegate methods if needed.
Here is an example for an asynchronous HTTP POST request:
// define your form fields here:
NSString *content = #"field1=42&field2=Hello";
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:#"http://www.example.com/form.php"]];
[urlRequest setHTTPMethod:#"POST"];
[urlRequest setHTTPBody:[content dataUsingEncoding:NSISOLatin1StringEncoding]];
// generates an autoreleased NSURLConnection
[NSURLConnection connectionWithRequest:request delegate:self];
Please refer to the NSURLConnection Class Reference for details on the delegate methods.
You can also send a synchronous request after generating the request:
[NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
If you pass a NSURLResponse ** as returning response, you will find the server's response in the object that pointer points to. Keep in mind that the UI will block while the synchronous request is processed.
Related
I am successfully posting data as follows:
NSMutableURLRequest *scriptrequest = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:#"myurl.com"]];
[scriptrequest setHTTPMethod:#"POST"];
NSString *sendData =[NSString stringWithFormat:#"ID=%#&action=List", ID, nil];
NSData *scriptdata = [sendData dataUsingEncoding:NSUTF8StringEncoding];
[scriptrequest setHTTPBody:scriptdata];
NSError *scripterr;
NSURLResponse *scriptresponse;
NSData *scriptResponseData = [NSURLConnection sendSynchronousRequest:scriptrequest returningResponse:&scriptresponse error:&scripterr];
My question is, is it possible to also attach GET data to the same call?
GET and POST are different types of HTTP Request.
GET Request is majorly used for fetching the web content while POST is for insert/update some content.
So eventually A single HTTP request can only be of one of the following.
Http types include:
GET
HEAD
POST
PUT
DELETE
TRACE
OPTIONS
CONNECT
PATCH
More technical details at Wikipedia:
http://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol
It looks to me like you are trying to retrieve data from your server, not update. A more typical way to form the request would be to GET http://myurl.com?ID=123&action=List. However, this really depends on how the server code is written.
I need help getting a basic understanding of uploading a file to a Django view via a post request. This is the Django form I'd like to upload the image to:
https://domfa.de/upload_profile/
This is the views.py code for this exact Django view URL:
def profile_picture(request):
if request.POST:
form = UserProfileForm(request.POST, request.FILES)
obj = form.save(commit=False)
obj.user_id = request.user.id
obj.profile_picture = obj.profile_picture
obj.save()
return render_to_response('profile.html', args, RequestContext(request))
else:
formNew = UserProfileForm()
args = {}
args.update(csrf(request))
args['uid'] = request.user.id
args['form'] = formNew
return render_to_response('profile.html', args, RequestContext(request))
And the actual form for this is extremely simple with just a single field for the actual profile picture:
class UserProfileForm(forms.ModelForm):
class Meta:
model = UserProfile
fields = ('profile_picture',)
def __init__(self, *args, **kwargs):
super(UserProfileForm, self).__init__(*args, **kwargs)
So the Django side works great, I'm always able to upload an image successfully as long as I'm logged in. I'm stuck though however on how to POST an image to this extremely simple Django view, I've already logged in to the Django server as a user using a separate NSUrl request:
UIImage *picture = [UIImage imageNamed:#"myFile.png"];
NSData *imageData = UIImagePNGRepresentation(picture);
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]
initWithURL:[NSURL
URLWithString:#"https://domfa.de/upload_profile/"]];
[request setHTTPMethod:#"POST"];
[request setValue:#"image/png" forHTTPHeaderField:#"Content-type"];
[request setHTTPBody:imageData];
NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSLog(#"%#", returnData);
So assuming all the Django code works, which it does, what's wrong with my objective-c code which does the actual image uploading?
And also, how could I get response messages from the server in the NSLog so I could better know why the server won't accept a file POST request?
Getting feedback what is going on when sending a HTTP request from iOS
The problem is that you are not passing in a pointer to a NSURLResponse object which you could examine after the request was made.
NSURLResponse *response;
NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:nil];
Now you can examine the output by looking at the object.
Why is it not uploading?
There are several issues with your approach: You are using django's forms API which is OK, but there are two pitfalls in your code:
CSRF You are not setting the the CSRF value correctly when submitting the form. You can workaround it by first accessing your form with a GET request, just like a browser would do it, then get the CSRF token from the cookies which the server set and then sending a POST request including the retrieved CSRF token. See also CSRF handling in AJAX requests
Data encoding You are not sending form data back to the view, but raw data instead. This will not work this way. You would have to send proper POST form data. You could do it manually or use ASIHTTPRequest which abstracts the cumbersome handling of multipart/form-data.
I would rethink the design decision to use a form to programatically upload a picture. Why not use something more like a REST API for this? There are great frameworks for implementing a clean REST API in django (e.g. http://tastypieapi.org/).
Maybe looking at the API description of Twitter and app.net could help inspiring you how to build this.
I am using HTTP Post method and initiating a synchronous request.
[NSURLConnection sendSynchronousRequest: ..]
For HTTP POST requests, the default time out is happening at 75 seconds as discussed in many threads.
But during that time out period of 75 seconds, Multiple web service requests are getting initiated for us for the same request raised with all the same parameters.
Please let us know What causes this multiple requests to get initiated? Is this due to HTTP POST in general or because of Synchronous request?
#iOS Sample Code
[body appendData:[[NSString stringWithFormat:#"\r\n--%#--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[request setHTTPBody:body];
[request addValue:[NSString stringWithFormat:#"%d", body.length] forHTTPHeaderField: #"Content-Length"];
[[NSURLCache sharedURLCache] setDiskCapacity:0];
[[NSURLCache sharedURLCache] setMemoryCapacity:0];
NSURLResponse *response;
response = nil;
urlData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
if(urlData)
{
NSString *responseString = [[NSString alloc] initWithData:urlData encoding:NSASCIIStringEncoding];
[self parseStringInformation:responseString infoDict:informationDictionary];
//NSLog(#"%#",responseString);
}
Without the server's request-response logs there are several possibilities.
Programmer Error: Have you already gone through all of "gotchya" type situations?
Have you put a logging message right before your "urlData = [NSURLConnection sendSynchronousRequest: ..." line to make sure your code is only calling it once?
Are you calling this function from within your main GUI thread, if you are that's not supported/recommended, which means it could be causing side-effects like what you're describing. https://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSURLConnection_Class/Reference/Reference.html
Are you sure your Request is set up as a POST and has the proper headers like "Content-type: multipart/form-data, boundary=X"
Web Server Responses: Without the web servers logs (or the code for the service your POSTing to) it's hard to say...
Perhaps your server is sending cyclical redirects to the client. If you don't implement a "connection:willSendRequest" then the redirects could be followed for ?X? amount of times for one request. http://developer.apple.com/library/mac/#documentation/cocoa/conceptual/urlloadingsystem/Articles/RequestChanges.html
API Error: You've found some corner case which is causing unwanted side effects. Maybe apple has an bug tracker or developer support forum?
If this is the case you'll have to work around the bug, until it's fixed. I suggest implementing the Asynchronous call chain. "Loading Data Asynchronously" https://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSURLConnection_Class/Reference/Reference.html
I am trying to send a suggestion from my app to a php file on my web server, I have tested the php script in my browser which sends an email to the user and stores the suggestion in my database, which all works fine.. And when running the following script I get a successful connection via IOS however i do not receive the results in my database..
NSString *post = [NSString stringWithFormat:#"http://blahblah.com/suggest.php?s=%#&n=%#&e=%#", suggestion, name, email];
// Create the request.
NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:post]
cachePolicy:NSURLRequestUseProtocolCachePolicy
timeoutInterval:60.0];
// create the connection with the request
// and start loading the data
NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
if (theConnection) {
NSLog(#"Connection establisted successfully");
} else {
NSLog(#"Connection failed.");
}
I have checked all the strings and encoded all spaces with %20 etc.. Can anyone see any glaringly obvious reason why my script won't work?
What is the easiest way to make a HTTP request from my app without opening safari?
You problem is that you're creating the connection, but are not sending the actual "connect" request. Instead of
NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
try using this piece of code:
NSURLResponse* response = nil;
NSData* data = [NSURLConnection sendSynchronousRequest:urlRequest returningResponse:&response error:nil]
This is quick and dirty solution, but keep in mind that while this connection is in progress, your UI thread will appear to be frozen. The way around it is to use asynchronous connection method, which is a bit more complicated than the above. Search web for NSURLConnection send asynchronous request - the answer is there.
A client is pondering development of an iPhone and iPad app and has asked an odd question: Is there any way to send data from an iOS device to a server other than using NSURL?
I think you could try using a POST request
responseData = [[NSMutableData data] retain];
NSMutableURLRequest *request = [NSMutableURLRequest
requestWithURL:[NSURL URLWithString:#"http://www.domain.com/your/servlet"]];
NSString *params = [[NSString alloc] initWithFormat:#"foo=bar&key=value"];
[request setHTTPMethod:#"POST"];
[request setHTTPBody:[params dataUsingEncoding:NSUTF8StringEncoding]];
[[NSURLConnection alloc] initWithRequest:request delegate:self];
That way the data would go inside the body of the request and not on the URL itself
The NSURL API isn't a way of getting data from a server. It's just a class for storing a URL. I suppose if you really want to avoid NSURL as much as possible, you could store URLs in an NSString, and then use appropriate APIs to convert it into an NSURL right before you use it.
To get data from a server, you would use either the NSURLSession API (modern) or NSURLConnection API (kind of crufty). Either is a fairly straightforward way to fetch data from an HTTP or HTTPS URL.
If you don't want to use either of those URL fetching APIs for some reason, you can write your own code using sockets or grab libcurl (MIT license) and link it into your app. Be aware that if you write your own socket code or use libcurl, assuming you're writing code for iOS, you'll need to occasionally use high-level APIs such as NSURL or CFHost to wake up the cellular radio.