I am making a login method on iOS that sends a GET request to a PHP page via url, when I try to read the output from the website, the data is read before the PHP can complete the mysql query, I was wondering if there were any way to wait until the webpage is completely done loading to read the data from it
code:
-(NSString *)getWebpageData:(NSString *)url {
NSURL *URL = [NSURL URLWithString:url];
NSError *error = nil;
NSString *content = [NSString stringWithContentsOfURL:URL encoding:NSUTF8StringEncoding error:&error];
return content;
}
I would try using NSURLConnection via sendAsynchronousRequest like so...
NSOperationQueue *myQueue = [[NSOperationQueue alloc]init];
[NSURLConnection sendAsynchronousRequest:request queue:myQueue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {
//do something
}];
It's mostly self-explanatory that when the handler block is fired you have your content.
Another option would be to invoke the NSURLConnectionDataDelegate. When you call your URL it will fire a few methods to let you know when things are done.
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
//Fired on error
}
- (void)connection:(NSURLConnection *)connection didSendBodyData:(NSInteger)bytesWritten totalBytesWritten:(NSInteger)totalBytesWritten totalBytesExpectedToWrite:(NSInteger)totalBytesExpectedToWrite
{
//Fired First
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
//Fired Second
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
//Fired Third
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
//Fired Fourth
}
Using the delegate methods you're likely going to want to leverage didReceiveData so that you have your data right there. Good luck.
Related
I am using NSURLConnection's sendSynchronousRequest to communicate with server. I wanted to handle authentication which can be achieved using connection delegates but delegates are not called for a synchronous request.
NSData *data = [NSURLConnection sendSynchronousRequest:UrlRequest returningResponse:&response error:&error];
dispatch_async(dispatch_get_main_queue(), ^{
if(!error)
{
// Do something
}
else
{
// Handle error
}
});
However i thought of sending all the request asynchronously using
[NSURLConnection connectionWithRequest:menuRequest delegate:self];
But i have multiple connection in the same class and each connection's success and error are used to perform different task.If i use async request error and success are heard by delegates which are same for all the request in that class, i cannot find out which request failed and which request succeeded. I have two question
If there is a way to implement https for synchronous request.
How to find which connection failed or succeeded among multiple connections in the same class for asynchronous request.
You can achieve this in different ways.
You can put creds in url like https://username:password#domain.tld/api/user.json
You can add add you creds to NSURLCredentialStorage before synchronous connection call.
You can use code below to achieve.
- (NSData *)sendSynchronousRequest:(NSURLRequest *)request returningResponse:(NSURLResponse *__strong*)response error:(NSError *__strong*)error
{
_finishedLoading=NO;
_receivedData=[NSMutableData new];
_error=error;
_response=response;
NSURLConnection*con=[NSURLConnection initWithRequest:request
delegate:self
startImmediately:NO];
[con start];
return _receivedData;
}
- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace {
return [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust];
}
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{
//handle the challenge
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
*_response=response;
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[_receivedData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
*_error=error;
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
}
I am looking for a sample to send and receive http GET request in iOS. All I want to
do is handle communication in background thread such that it does not block main thread
and also want to handle http standard error code. Can anyone suggest me reference code or
example to handle http response data and handle proper memory management?
Any help will be thankful.
Two methods to achieve it:
1) NSURLCOnnection sendAsynchronousRequest method:
NSString *strURL= [NSString stringWithFormat:#"http://www.google.com/"];
NSURL *URL = [NSURL URLWithString:[strURL stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSURLRequest *requestURL = [[NSURLRequest alloc] initWithURL:URL];
[NSURLConnection sendAsynchronousRequest:requestURL
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
{
NSLog(#"Response is:%#",[[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding]);
}];
2) Create and fire request then NSURLConnection Delegate Methods to get the response:
// Create the request.
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:#"http://google.com"]];
// Create url connection and fire request
NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];
#pragma mark NSURLConnection Delegate Methods
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
// A response has been received, this is where we initialize the instance var you created
// so that we can append data to it in the didReceiveData method
// Furthermore, this method is called each time there is a redirect so reinitializing it
// also serves to clear it
_responseData = [[NSMutableData alloc] init];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
// Append the new data to the instance variable you declared
[_responseData appendData:data];
}
- (NSCachedURLResponse *)connection:(NSURLConnection *)connection
willCacheResponse:(NSCachedURLResponse*)cachedResponse {
// Return nil to indicate not necessary to store a cached response for this connection
return nil;
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
// The request is complete and data has been received
// You can parse the stuff in your instance variable now
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
// The request has failed for some reason!
// Check the error var
}
I have WSDL url with me. I have two methods in the WSDL, I need to access those method and get response using REST api.
What I have tried is below?
I used the below code snippets for request and response. But I didnt get any response.
- (void)viewDidLoad
{
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURLNSURL : [URLWithString"https://mywebsite.com/service.svc?wsdl"]];
[request setHTTPMethod"IBillingSubmissionService_RegisterDevice_InputMessage"];
NSURLConnection *myConnection = [NSURLConnection connectionWithRequest:request delegate:self];
[myConnection start];
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
[dataWebService setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
NSLog(#"Response: %#",data);
[dataWebService appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSString *responseString = [[NSString alloc] initWithData:dataWebService encoding:NSUTF8StringEncoding];
NSLog(#"Response: %#",responseString);
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
NSLog(#"Eror during connection: %#", [error description]);
}
What ever I am doing above is correct? Can some one provide a sample code snippet to call and get response using REST?
I want to know the below:
1) How to pass the value to WSDL method?
2) How to pass a reqiest and get response?
You can not directly use the wsdl webservices in objective c but you have to first construct the reference base classes.
You can use wsdl2objc code generator to construct the base classes to call the wsdl webservice
and Please refer the usage instructions for how to use it.
UPDATE: As a my advice you can see my answer here
Anybody knows how to wait the response of a http request? In my code, I am doing a http request to an url and then what i need to do, it is to check the http response in order to decide different treatment. I have something like this:
-(void)check{
[self fetchURL:#"http://something"];
if(response != nil || [response length] != 0){
do something....
}
else{
do something else....
}
}
-(void)fetchURL:(NSString *)urlWeb{
NSURL *url = [NSURL URLWithString:urlWeb];
NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
[connection scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
[connection start];
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
NSLog(#"INSIDE OF didReceiveResponse");
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{
NSLog(#"INSIDE OF didFailWithError");
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection{
NSLog(#"INSIDE OF connectionDidFinishLoading");
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
// Append the new data to receivedData.
// receivedData is an instance variable declared elsewhere.
NSLog(#"inside of didReceiveData");
response = [NSString stringWithUTF8String:[data bytes]];
NSLog(#"response: %#", response);
}
I have been trying different options that I have seen around here, but i cant stop the execution of my code and wait for that answer...that means when I check the response of my http request, it always appears empty or with a nil reference...
any help how to figure out??
thanks
You can't evaluate the response value right after your 'fetchUrl' call, because your request is asynchronous, and your code goes on with the execution without waiting for the answer. You will receive the response value only in one of the delegate method, so there's the place where you should check the result.
If you really want to make a synchronous request you can use sendSynchronousRequest:returningResponse:error: like this
NSError *error;
NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
if(data){
//use data
}
else{
//check error domain and code
}
(See the Apple NSURLConnection Reference)
But keep in mind that your program will be stuck on this call till it receives a response or goes timeout.
Why don't you write this code:
if(response != nil || [response length] != 0){
do something....
}
else{
do something else....
}
In - (void)connectionDidFinishLoading:(NSURLConnection *)connection; method it wouldn't execute unless you have your complete proper response.
And Just for ado: Right to way to get data properly should be:
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
[_responseData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection{
NSString *string = [[NSString alloc] initWithData:_responseData encoding:NSUTF8StringEncoding];
if (string)
NSLog(#"string = %#", string);
}
Did you try checking the respons witin connectionDidFinishLoading: ?
That is the very delegate method which is called when the data was transferred successfully. Before that point in time, you should not expect any meaningful data.
Besides - didReceiveData should provide you with portions of data received in the meantime. Apparently you do not seem to process it nor just to store it for later evaluation (witin connectionDidFinishLoading)
I am new to iOS and working on an app which runs on a real device (iPad). So, when I launch my app on the iPad after the view is visible, the app should be able poll a web server or something (without any user interaction) and get some information over HTTP and based on this information, I want fill some text fields in the app view. can you let me know if it is possible to do something like this in iOS? if so how and some sample pieces of code would be much appreciated.
Thanks.
You can download information over http using NSURLConnection in the viewWillAppear or viewDidLoad. After download the data if its XML parse using NSXMLParser (or any other XML parser for iOS).
//Lets say you have download and process method
- (void)downloadAndProcess
{
//URL you want to download Info from
NSURL* url = [NSURL URLWithString:#"http://google.com"];
//Make a mutable url request
NSMutableURLRequest* req = [[NSMutableURLRequest alloc] initWithURL:url cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData timeoutInterval:60];
NSURLConnection* conn = [NSURLConnection connectionWithRequest:req delegate:self];
if(conn)
{
//NSMutableData receivedData is an instance variable
receivedData = [[NSMutableData alloc] init];
}
}
//NSURLConnection Delegate methods here
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
[receivedData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[receivedData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
NSLog(#"Error downloading data :%#",[error localizedDescription]);
// release receivedData object when connection fails
[receivedData release],receivedData = nil;
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
// Connection did finish downloading data which you can process based on what your data is
// release receivedData object once you are done processing it.
[receivedData release],receivedData = nil;
}