Voici un exemple de classe permettant d’envoyer des requêtes pour l’architecture REST vers un serveur

Les requêtes REST utilisent le protocole HTTP pour le transport des données

restRequest.h

#import <Foundation/Foundation.h>

@interface restRequest : NSObject <NSURLConnectionDelegate, NSURLConnectionDataDelegate> {
SEL callback; // Selecteur vers la fonction de retour
id delegate; // objet cible pour l'appel de la fonction de retour
int status; // code HTTP
bool done; // true si la requête est terminée

NSMutableString *method;
NSMutableString *url;
NSMutableString *payload;

NSMutableURLRequest *request;
NSURLConnection *connection;
NSMutableData *dta;
NSMutableString *result;
}

@property (nonatomic,retain) NSMutableData *dta;

@property (nonatomic,retain) NSMutableString *method;
@property (nonatomic,retain) NSMutableString *url;
@property (nonatomic,retain) NSMutableString *payload;

@property (nonatomic,retain) NSMutableURLRequest *request;
@property (nonatomic,retain) NSURLConnection *connection;

@property (nonatomic) SEL callback;
@property (nonatomic,assign) id delegate;

@property (nonatomic) int status;
@property (nonatomic) bool done;
@property (nonatomic,retain) NSMutableString *result;

-(id)initWithCallback:(SEL)cal andDelegate:(id)dl;
-(void)start;
-(void)cancel;
@end

restRequest.m

#import "restRequest.h"

@implementation restRequest

@synthesize callback;
@synthesize delegate;

@synthesize url;
@synthesize method;
@synthesize payload;

@synthesize connection;
@synthesize request;
@synthesize dta;
@synthesize status;
@synthesize result;
@synthesize done;

-(id)initWithCallback:(SEL)cal andDelegate:(id)dl {

    self = [super init];
    if(self) {
        callback = cal; // Selecteur vers la fonction de retour
        delegate = [dl retain]; // objet cible de la fonction de retour
        status = -1; // code de retour HTTP
        done = FALSE; // indique si la requête est terminée

        dta = [[NSMutableData alloc] init]; // buffer
        url = [[NSMutableString alloc] init]; // url appelée
        method = [[NSMutableString alloc] initWithString:@"GET"]; // méthode HTTP : GET / POST / PUT, ...
        payload = [[NSMutableString alloc] init]; // contenu de la requete (Body)

        result = [[NSMutableString alloc] init]; // résultat de la requête
    }

    return self;

}
-(void)dealloc {

    [self cancel];

    done = TRUE;

    delegate = nil;
    callback = nil;

    [dta release];
    [url release];
    [method release];
    [payload release];
    [result release];

    if(request){
        [request release];
        request = nil;
    }

    [super dealloc];
}
-(void)start {

    status = 0;

    [dta setLength:0];

        [result setString:@""];
        NSString *full = [NSString stringWithFormat:@"http://%@/%@",@"http://www.url-de-base.com/",url];
        NSURL *myurl = [NSURL URLWithString:full];

        if(request){
            [request release];
            request = nil;
        }

        request = [[NSMutableURLRequest alloc] initWithURL:myurl];
        [request setHTTPMethod:method];
        if([payload length] > 0) [request setHTTPBody:[payload dataUsingEncoding:NSUTF8StringEncoding]];
        //[request setValue:@"application/xml" forHTTPHeaderField:@"Content-Type"]; // spécifie le format du contenu de la requête
        [request setTimeoutInterval:10];

        connection = [NSURLConnection connectionWithRequest:request delegate:self];
      [connection start];

}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [dta appendData:data];
}
-(void)connection:(NSURLConnection *)sconnection didFailWithError:(NSError *)error {
    NSLog(@"Error restRequest %@",[error localizedDescription]);
    [dta setLength:0];

    status = -2;

    if(delegate && [delegate respondsToSelector:callback]) [delegate performSelector:callback withObject:self];

    connection = nil;
    delegate = nil;
    callback = nil;

    done = TRUE;
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    if([response respondsToSelector:@selector(statusCode)]){
        status = [(NSURLResponseInternal *)response statusCode];
    }
}
-(void)connectionDidFinishLoading:(NSURLConnection *)sconnection {

    NSMutableString *res = [[NSMutableString alloc] initWithData:dta encoding:NSUTF8StringEncoding];
    [result setString:res];

    if(delegate && [delegate respondsToSelector:callback]){
        [delegate performSelector:callback withObject:self];
        [delegate release];
    }

    connection = nil;
    delegate = nil;
    callback = nil;
    done = TRUE;

    [res release];
}
-(void)cancel {
    if(connection){
        [connection cancel];
        connection = nil;
    }

    if(request){
        [request release];
        request = nil;
    }

    delegate = nil;
    callback = nil;
    done = TRUE;
}

@end

Pour l’utiliser :

-(void)start_request {

    restRequest *rest = [[restRequest alloc] initWithCallback:@selector(register_response:) andDelegate:self];

    [[(restRequest *)rest url] setString:@"appel/fonction.php"];
    [[(restRequest *)rest method] setString:@"PUT"];
    [[(restRequest *)rest payload] setString:@"contenu xml, json, ..."];

    [(restRequest *)rest start];

}
-(void)register_response:(restRequest *)res {

    if (res.status == 204) {
        // success
        NSString *resultat = res.result;
    }
    else if(res.status == 404){
        // document introuvable ...
    }
    else if(res.status == 500){
        // erreur interne
    }
    else if(res.status == -2){
        // impossible d'établir la connection, probablement un problème de réseau
    }

}

Tags: ios, iphone, NSURLConnection, objective c, rest

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