Another problem with stringByEvaluatingJavaScriptFromString

[Danneman]

Ive got a js-function in a webview that focuses on a select-list and selects it, which works fine.

function selectLetter()
{
document.getElementById("select_letter").focus();
document.getElementById("select_letter").select();
}

However, when invoking the same functionality from obj-c code using stringByEvaluatingJavaScriptFromString, it wont execute. Nothing happens.

[self.webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"document.getElementById('select_letter').focus();"]];
[self.webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"document.getElementById('select_letter').select();"]];

Ive tried other types of code with stringByEvaluatingJavaScriptFromString manipulating just that select-list, which has worked fine. For instance:

[self.webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"document.getElementById('select_letter').style.visibility='hidden';"]];

Any suggestions?

[geppi24]

Hey,
I ran into the same problem. What I figuered out so far, it doesn't help either to call the JS-function which should does the job via the stringByEvaluatingJavaScriptFromString:-method.

Any help is highly apriciated!

[Danneman]

Unfortunately, I didnt find any solution to this and had to abandon the idea completely :/

[smasher]

Are you waiting until after the content has loaded before you call this function? Otherwise you'll get nothing, of course.

You could also try logging the intermediate steps, see where you're getting stuck.

NSString *result;

result = [self.webView stringByEvaluatingJavaScriptFromString: @"document"];
NSLog (@"%@", result); //should log the document object?

result = [self.webView stringByEvaluatingJavaScriptFromString: @"document.getElementById"];
NSLog (@"%@", result); //should log a function

result = [self.webView stringByEvaluatingJavaScriptFromString: @"document.getElementById('select_letter')"];
NSLog (@"%@", result); //should log the node

[iphonegamedeveloper]

Originally Posted by smasher

Are you waiting until after the content has loaded before you call this function? Otherwise you'll get nothing, of course.

You could also try logging the intermediate steps, see where you're getting stuck.

NSString *result;

result = [self.webView stringByEvaluatingJavaScriptFromString: @"document"];
NSLog (@"%@", result); //should log the document object?

result = [self.webView stringByEvaluatingJavaScriptFromString: @"document.getElementById"];
NSLog (@"%@", result); //should log a function



result = [self.webView stringByEvaluatingJavaScriptFromString: @"document.getElementById('select_letter')"];
NSLog (@"%@", result); //should log the node

How to validate whether the element is present or not. For me in both cases result is same.Its not printing any values in log. I need to check whether the particular id is present or not.Please help

[apatsufas]

If NSLog doesn't print anything to the log it means that the NSString you are trying to print is empty.