Can't set headers on my WKWebView POST request

Question

I want to do a POST request to my WKWebView but the headers doesn't get set when I monitor the requests with Charles so the request fails. What is wrong here?

NSString *post = [NSString stringWithFormat: @"email=%@&password=%@", email, password];
NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSString *contentLength = [NSString stringWithFormat:@"%d", postData.length];

NSURL *url = [NSURL URLWithString:@"http://materik.me/endpoint"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPMethod:@"POST"];
[request setHTTPBody:postData];
[request setValue:contentLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setValue:@"application/json" forHTTPHeaderField:@"Accept"];

[webview loadRequest:request];

And this is what Charles says the request is like:

POST /endpoint HTTP/1.1
Host: materik.me
Content-Type: application/x-www-form-urlencoded
Origin: null
Connection: keep-alive
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
User-Agent: Mozilla/5.0 (iPhone; CPU OS 8_0 like Mac OS X)
Content-Length: 0
Accept-Language: en-us
Accept-Encoding: gzip, deflate

So, as you can see, Content-Length is 0, Accept is not application/json and no request body were sent.

Thanks for any help.

Have you tried URLEncoding the email and password values before converting to NSData? — Steven Veltema, Oct 08 '14 at 10:15
@StevenVeltema I've tried to send `email=foo&password=bar` but it doesn't work either — Mattias Farnemyhr, Oct 08 '14 at 10:39
Updated the question!! Realized that it was the WKWebView I was using, it works fine on the UIWebView. — Mattias Farnemyhr, Oct 08 '14 at 12:20

OhadM · Answer 1 · 2020-02-20T08:36:44.983

As the OP stated, I have also confirmed in Charles that the body is 0 bytes after webView.load(request).

There's a workaround for this WKWebView bug, we will initiate a POST request using URLSession convert the data returned by the server to String and instead of loading the url we will use loadHTMLString which will:

Set the webpage contents and base URL.

and the content is our converted string:

var request = URLRequest(url: URL(string: "http://www.yourWebsite")!)
request.httpMethod = "POST"
let params = "do=something&andAgain=something"
request.httpBody = params.data(using: .utf8)

let task = URLSession.shared.dataTask(with: request) { (data : Data?, response : URLResponse?, error : Error?) in
        if data != nil {
            if let returnString = String(data: data!, encoding: .utf8) {
                self.webView.loadHTMLString(returnString, baseURL: URL(string: "http://www.yourWebsite.com")!)
            }
        }
}
task.resume()

Brilliant. Still an issue as at 2018-09-13 – Christopher Smit Sep 13 '18 at 19:37 — Christopher Smit, Sep 13 '18 at 19:37
Worked like a charm even in 2019-0925 :D – Droid GEEK Sep 25 '19 at 16:03 — Droid GEEK, Sep 25 '19 at 16:03
Worked like a charm..Thanks – Dhaval Bhadania May 27 '21 at 08:36 — Dhaval Bhadania, May 27 '21 at 08:36

score 17 · Accepted Answer · edited May 23 '17 at 12:26

I had the same problem with WKWebView, that I decided to use instead of UIWebView to avoid the pickers crash in iOS 8. There are two ways that I can think of:

Use NSURLConnection to make the request and then fill the WKWebView with it's response data. You can find an example here: https://stackoverflow.com/a/10077796/4116680 (You only need connection:didReceiveData: and connectionDidFinishLoading: from the delegate if you don't use a self signed SSL certificate)
Use a JavaScript to make the POST request. Here is an example:

Create file eg. "POSTRequestJS.html":

<html>
    <head>
        <script>
            //POST request example:
            //post('URL', {key: 'value'});
            function post(path, params) {
                var method = "post";
                var form = document.createElement("form");
                form.setAttribute("method", method);
                form.setAttribute("action", path);

                for(var key in params) {
                    if(params.hasOwnProperty(key)) {
                        var hiddenField = document.createElement("input");
                        hiddenField.setAttribute("type", "hidden");
                        hiddenField.setAttribute("name", key);
                        hiddenField.setAttribute("value", params[key]);

                        form.appendChild(hiddenField);
                    }
                }

                document.body.appendChild(form);
                form.submit();
            }
        </script>
    </head>
    <body>
    </body>
</html>

And in your code after where you want to load your request:

NSString *path = [[NSBundle mainBundle] pathForResource:@"POSTRequestJS" ofType:@"html"];
NSString *html = [[NSString alloc] initWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
WKWebView.navigationDelegate = self;
[WKWebView loadHTMLString:html baseURL:[[NSBundle mainBundle] bundleURL]];

Add method:

- (void)makePostRequest
{
    NSString *postData = [NSString stringWithFormat: @"email=%@&password=%@", email, password];
    NSString *urlString = @"http://materik.me/endpoint";
    NSString *jscript = [NSString stringWithFormat:@"post('%@', {%@});", urlString, postData];

    DLog(@"Javascript: %@", jscript);

    [WKWebView evaluateJavaScript:jscript completionHandler:nil];

    didMakePostRequest = YES;
}

And last add the WKNavigationDelegate:

- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation
{
    if (!didMakePostRequest) {
        [self makePostRequest];
    }
}

thanks, seems like a really nice solution. but is this a bug in wkwebview do you think that they will solve? thanks again, will try this out! — Mattias Farnemyhr, Oct 14 '14 at 08:40
Hi @Spas This is the same which I am using , and it was working fine for every app I try to Login. but for facebook, I think facebook still neeed referrer to be m.facebook.com only as facebook returns me "do no enter your password on site not located at facebook.com" I am really stuck with it as while submitting form , cannot set header, I tried editing request at 'decidePolicyForNavigationAction' but as it is not mutable , it is not working that way.I'll be more then Happy If you have a way to resolve it — Priyanka, Aug 30 '16 at 11:06
thx for answer. I changed parameter format to this as an example in html format, {key: 'value'}. NSString *postData = [NSString stringWithFormat: @"email:'%@',password='%@'", email, password]; — Thein, Oct 26 '17 at 10:12
I am new to java script, on following this post, I am getting - Reference error: Can't find variable: post (for function name). Complete error: Error Domain=WKErrorDomain Code=4 "A JavaScript exception occurred" UserInfo={WKJavaScriptExceptionLineNumber=1, WKJavaScriptExceptionMessage=ReferenceError: Can't find variable: post, WKJavaScriptExceptionColumnNumber=11, WKJavaScriptExceptionSourceURL=file:///xxx, NSLocalizedDescription=A JavaScript exception occurred} Can anyone suggest what wrong I am doing? — Lakshmi, Jul 23 '19 at 11:53

score 8 · Answer 3 · answered Jan 13 '16 at 01:35

8

This appears to be a bug.
https://bugs.webkit.org/show_bug.cgi?id=140188

Hopefully it will be addressed soon. In the meantime, reverting to UIWebView or implementing the workaround proposed by Spas Bilyarski in his answer seems to be the best options.

answered Jan 13 '16 at 01:35

Paul Roe

81
1
1

2

the bug has been fixed a month ago https://bugs.webkit.org/show_bug.cgi?id=167131 – chebur Feb 13 '17 at 10:44
1

@chebur Do you know the iOS version number that first adopted this fix? – algrid Feb 13 '18 at 15:34
1

@algrid iOS 11 or High Sierra [see here](https://bugs.webkit.org/show_bug.cgi?id=167131#c5) – Azules Mar 13 '18 at 09:22

score 8 · Answer 4 · edited Jul 28 '17 at 08:00

I use this delegate method and it works !!!

#pragma mark - WKNavigationDelegate

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler{

    NSLog(@"%@",navigationAction.request.allHTTPHeaderFields);

    NSString *accessToken = @"Bearer 527d3401f16a8a7955aeae62299dbfbd";
    NSMutableURLRequest *request = [navigationAction.request mutableCopy];

    if(![[request.allHTTPHeaderFields allKeys] containsObject:@"Authorization"]){
        [request setValue:accessToken forHTTPHeaderField:@"Authorization"];

        decisionHandler(WKNavigationActionPolicyCancel);
        [Helper hideProgressHUD];
        [webView loadRequest:request];

    } else {
        decisionHandler(WKNavigationActionPolicyAllow);
    }
}

It is going infinite in iOS 10.3 for httpBody. – Max Sep 26 '17 at 05:30 — Max, Sep 26 '17 at 05:30

score 2 · Answer 5 · answered Jun 07 '16 at 11:35

I can confirm this problem. A simple workaround for me was an AJAX request, with jQuery:

$.ajax({
    type : 'POST',
    url : $('#checkout-form').attr('action'),
    data : $('#checkout-form').serialize()
}).done(function(response, status) {
    // response if return value 200
}).fail(function(status, error) {
    console.log(error);
});

where my form looks like

<form id="checkout-form" method="POST" action="/shop/checkout">
...
</form>

I hope this helps somebody...

score 1 · Answer 6 · edited Mar 15 '17 at 04:58

workaround: trick by using html5 & javascript.

Add a html5 file with content below to your xcode project. To post data by using javascript & h5 form:

<html>
    <head>
        <script>
            //how to call： post('URL', {"key": "value"});
            function post(path, params) {
                var method = "post";
                var form = document.createElement("form");
                form.setAttribute("method", method);
                form.setAttribute("action", path);
                for(var key in params) {
                    if(params.hasOwnProperty(key)) {
                        var hiddenField = document.createElement("input");
                        hiddenField.setAttribute("type", "hidden");
                        hiddenField.setAttribute("name", key);
                        hiddenField.setAttribute("value", params[key]);
                        form.appendChild(hiddenField);
                    }
                }
                document.body.appendChild(form);
                form.submit();
            }
        </script>
    </head>
    <body>
    </body>
</html>

Load the h5 file to WKWebView:

WKWebViewConfiguration* config = [[WKWebViewConfiguration alloc] init];
config.preferences = [[WKPreferences alloc]init];
config.preferences.javaScriptEnabled = YES;
WKWebView* webView = [[WKWebView alloc] initWithFrame:[UIScreen mainScreen].bounds configuration:config];
webView.navigationDelegate = self;
[self.view addSubview:webView];
NSString *path = [[NSBundle mainBundle] pathForResource:@"JSPOST" ofType:@"html"];
NSString *html = [[NSString alloc] initWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
[webView loadHTMLString:html baseURL:[[NSBundle mainBundle] bundleURL]];

Prepare the parameters to post. ie. a string & an array of dictionary Note: when turn array to json string by using NSJSONSerialization, '\r' may be added automaticly. You must remove all the '\r' in the json string, or the javascript cannot be parsed correctly.

// parameters to post
NSString* name = @"Swift";
NSArray* array = @[@{@"id":@"1", @"age":@"12"}, @{@"id":@"2", @"age":@"22"}];
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:array options:NSJSONWritingPrettyPrinted error:nil];
NSString *jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
jsonString = [jsonString stringByReplacingOccurrencesOfString:@"\"" withString:@"\\\'"];
// trim spaces and newline characters
jsonString = [jsonString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
jsonString = [jsonString stringByReplacingOccurrencesOfString:@"\r" withString:@""];
jsonString = [jsonString stringByReplacingOccurrencesOfString:@"\n" withString:@""];
NSString *postData = [NSString stringWithFormat: @"'name':'%@', 'contacts':'%@'", name, jsonString];
// page url to request
NSString *urlStr = @"http:api.example.com/v1/detail";
// javascript to evalute
NSString *jscript = [NSString stringWithFormat:@"post('%@',{%@});", urlStr, postData];
//NSLog(@"Javzascript: %@", jscript);

Put this in the WKWebView's delegate: didFinishNavigation

// call the javascript in step 3
(void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation {
     GCD_MAIN((^{
          [_web evaluateJavaScript:jscript completionHandler:^(id object, NSError * _Nullable error) {
               if (error) {
                   NSLog(@"----------->>>>>>>>>>>>> evaluateJavaScript error : %@", [error localizedDescription]);
               }
          }];
     }));
 }

score 0 · Answer 7 · edited Jan 17 '17 at 01:13

0

WKWebView.load method doesn't work with post request with post body. You have to use JavaScript to do the trick, check WKWebView.evaluateJavascript.

It maybe a bug, but Apple hasn't addressed it till now.

edited Jan 17 '17 at 01:13

Igor

11,227
4
49
69

answered Jan 16 '17 at 23:39

Xiaodong Ma

31
2

Can't set headers on my WKWebView POST request

7 Answers7

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