UIWebView: get attributes from hyperlink clicked - html

Question

I have html page loaded via UIWebView. If user selects link that looks like:
<a webview="2" href="#!/accounts-cards/<%= item.acctno %>"></a>
I can get href value clicked in UIWebViewDelegate method from NSURLRequest:
webView:shouldStartLoadWithRequest:navigationType:
But how I can get attribute value from this hyperlink (webview="2") assuming that attribute name "webview" determined?

Answer 1

You can get your attribute "webview", with the help of JavaScript and after that you can send that attribute and its value to native Objective C code.
Add this JavaScript code to your HTML page inside script tag:
function reportBackToObjectiveC(string)
{
var iframe = document.createElement("iframe");
iframe.setAttribute("src", "callback://" + string);
document.documentElement.appendChild(iframe);
iframe.parentNode.removeChild(iframe);
iframe = null;
}
var links = document.getElementsByTagName("a");
for (var i=0; i<links.length; i++) {
links[i].addEventListener("click", function() {
var attributeValue=links[i].webview; //this will give you your attribute(webview) value.
reportBackToObjectiveC(attributeValue);
}, true);
}
after this your webViewDelegate method will call:
- (BOOL)webView:(UIWebView *)wView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{
{
if (navigationType == UIWebViewNavigationTypeLinkClicked)
{
NSURL *URL = [request URL];
if ([[URL scheme] isEqualToString:#"callback"])
{
//You can get here your attribute's value.
}
}

Answer 2

You need to change href of your links. First inject javascript script, that patches your links.
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
NSString *js = #"var allElements = document.getElementsByTagName('a');"
"for (var i = 0; i < allElements.length; i++) {"
" attribute = allElements[i].getAttribute('webview');"
" if (attribute) {"
" allElements[i].href = allElements[i].href + '&' + attribute;"
" }"
"}";
[webView stringByEvaluatingJavaScriptFromString:js];
}
Links will be converted into format (note &2 in href attribute):
<a webview="2" href="#!/accounts-cards/<%= item.acctno %>&2"></a>
Then you can get your callback and parse you webview param value:
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
NSArray *array = [request.URL.absoluteString componentsSeparatedByString:#"&"];
if (array.count > 2) {
NSLog(#"webview value = %#", array[1]);
}
return YES;
}