我有一个UIWebView,使得AJAX调用外部服务。 当离线我需要赶论文请求并返回本地JSON。
我实现了一个NSURLProtocol,我设法抓住了AJAX请求,问题是jQuery的总是返回一个0错误代码:
$.ajax({
url: url,
dataType: 'json',
contentType: "application/json",
success: function(jsonData){
alert("success :");
},
error: function (request, status, error) {
alert("failure :" + request.status );
}
});
我总是得到request.status = 0
为了测试我的协议我试图嘲弄我的HTML内的图像和它的伟大工程。
- HTML请求从google.fr图像=> 工作正常
- AJAX调用一个JSON在亚马逊=> 失败
这是我的全面实施:
#import "EpubProtocol.h"
@implementation EpubProtocol
#pragma mark - NSURLProtocol
+ (BOOL)canInitWithRequest:(NSURLRequest *)request {
BOOL awsRequest = [self request:request contains:@"s3.amazonaws.com"];
BOOL imgRequest = [self request:request contains:@"google.fr"];
BOOL match = awsRequest || imgRequest;
return match;
}
+ (NSURLRequest*)canonicalRequestForRequest:(NSURLRequest*)theRequest
{
return theRequest;
}
- (void)startLoading {
NSURLRequest *request = [self request];
//Mock Amazon call
if([EpubProtocol request:request contains:@"s3.amazonaws.com"]) {
NSString *path = [[NSBundle bundleForClass:self.class] pathForResource:@"epub1" ofType:@"json"];
NSData *data = [NSData dataWithContentsOfFile:path];
[self mockRequest:request mimeType:@"application/json" data:data];
}
//Mock image call
else if([EpubProtocol request:request contains:@"google.fr"]) {
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[NSURLConnection sendAsynchronousRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.itespresso.fr/wp-content/gallery/yahoo/1-yahoo-logo.jpg"]] queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {
[self mockRequest:request mimeType:@"image/jpeg" data:data];
}];
}
}
- (void)stopLoading
{
NSLog(@"Did stop loading");
}
#pragma mark - Request utils
+ (BOOL) request:(NSURLRequest*)request contains:(NSString*)domain {
NSString *str = [[request URL] absoluteString];
NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF contains[cd] %@", domain];
return [pred evaluateWithObject:str];
}
#pragma mark - Mock responses
-(void) mockRequest:(NSURLRequest*)request mimeType:(NSString*)mimeType data:(NSData*)data {
id client = [self client];
NSHTTPURLResponse *response = [[NSHTTPURLResponse alloc] initWithURL:[request URL] MIMEType:mimeType expectedContentLength:-1 textEncodingName:nil];
[client URLProtocol:self didReceiveResponse:response
cacheStoragePolicy:NSURLCacheStorageNotAllowed];
[client URLProtocol:self didLoadData:data];
[client URLProtocolDidFinishLoading:self];
}
@end
该问题来源于webkit的哪些块由于跨域原点请求的响应。 由于我们嘲笑的反应,我们必须强制访问控制允许来源。
然后,我们还需要给力的内容类型的响应。
这里就是奇迹发生:
NSDictionary *headers = @{@"Access-Control-Allow-Origin" : @"*", @"Access-Control-Allow-Headers" : @"Content-Type"};
NSHTTPURLResponse *response = [[NSHTTPURLResponse alloc] initWithURL:request.URL statusCode:200 HTTPVersion:@"1.1" headerFields:headers];
最终的实施方案中:
#import "EpubProtocol.h"
@implementation EpubProtocol
#pragma mark - NSURLProtocol
+ (BOOL)canInitWithRequest:(NSURLRequest *)request {
BOOL isAwsRequest = [self request:request contains:@"s3.amazonaws.com"];
return isAwsRequest;
}
+ (NSURLRequest*)canonicalRequestForRequest:(NSURLRequest*)theRequest
{
return theRequest;
}
- (void)startLoading {
NSURLRequest *request = [self request];
//Mock Amazon call
if([EpubProtocol request:request contains:@"s3.amazonaws.com"]) {
NSString *path = [[NSBundle bundleForClass:self.class] pathForResource:@"epub1" ofType:@"json"];
NSData *data = [NSData dataWithContentsOfFile:path];
[self mockRequest:request data:data];
}
}
- (void)stopLoading
{
NSLog(@"Did stop loading");
}
#pragma mark - Request utils
+ (BOOL) request:(NSURLRequest*)request contains:(NSString*)domain {
NSString *str = [[request URL] absoluteString];
NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF contains[cd] %@", domain];
return [pred evaluateWithObject:str];
}
#pragma mark - Mock responses
-(void) mockRequest:(NSURLRequest*)request data:(NSData*)data {
id client = [self client];
NSDictionary *headers = @{@"Access-Control-Allow-Origin" : @"*", @"Access-Control-Allow-Headers" : @"Content-Type"};
NSHTTPURLResponse *response = [[NSHTTPURLResponse alloc] initWithURL:request.URL statusCode:200 HTTPVersion:@"1.1" headerFields:headers];
[client URLProtocol:self didReceiveResponse:response
cacheStoragePolicy:NSURLCacheStorageNotAllowed];
[client URLProtocol:self didLoadData:data];
[client URLProtocolDidFinishLoading:self];
}
@end
没什么特别的JS:
function loadJSONDoc()
{
var url = "https://s3.amazonaws.com/youboox_recette/epub.json";
$.ajax({
url: url,
dataType: 'json',
contentType: "application/json",
success: function(jsonData){
alert('success');
document.getElementById("myDiv").innerHTML='<p>'+$.param(jsonData)+'</p>';
},
error: function (request, status, error) {
alert("failure :" + request.status );
}
});
}
我不得不做类似的东西,前一段时间。
首先,我设法找到的代码,可以使UIWebViewDelegate赶上Ajax调用,所以在我的web应用程序的一部分我有:
//code to extend XMLHttpRequest, and have ajax call available in uiwebviewdelegate.
var s_ajaxListener = new Object();
s_ajaxListener.tempOpen = XMLHttpRequest.prototype.open;
s_ajaxListener.tempSend = XMLHttpRequest.prototype.send;
s_ajaxListener.callback = function () {
window.location=this.url;
};
XMLHttpRequest.prototype.open = function(a,b) {
if (!a) var a='';
if (!b) var b='';
s_ajaxListener.tempOpen.apply(this, arguments);
s_ajaxListener.method = a;
s_ajaxListener.url = b;
if (a.toLowerCase() == 'get') {
s_ajaxListener.data = b.split('?');
s_ajaxListener.data = s_ajaxListener.data[1];
}
}
XMLHttpRequest.prototype.send = function(a,b) {
if (!a) var a='';
if (!b) var b='';
s_ajaxListener.tempSend.apply(this, arguments);
if(s_ajaxListener.method.toLowerCase() == 'post')s_ajaxListener.data = a;
s_ajaxListener.callback();
}
然后在iOS中我在UIWebViewDelegate shouldStartLoad不归路(我的条件有点丑):
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
if ([[[request URL] scheme] rangeOfString:@"https"].length > 0)
{
return NO;
}
return YES;
}
在最重要的是我必须登记自己的协议:
[NSURLProtocol registerClass:[MyProtocol class]];
随着StartLoad实现。 你也应该有子类的canInitWithRequest
+ (BOOL)canInitWithRequest:(NSURLRequest *)request
{
if ([request.URL.scheme rangeOfString:@"https"].length > 0)
{
return YES;
}
return NO;
}
要告诉大家,它应该是使用了该请求的协议。
而且不要忘了,当你有网络注销。
如果你不想与NSURLProtocol打扰实现,你可以用我自己的: https://github.com/bcharp/BOURLProtocol ;)
希望能帮助到你 !