使用UIWebview检索HTML标签

Question

i'm developing a custom webview on iOS which should give users special options when selecting certain elements on a webpage, therefor I'm extending the UIWebview and am adding my own buttons to the sharedMenuController. Because the page shown is made up from xml using xsl to style it, there is extra data in certain tags, eg

<p data-type="MC"><img src="annotation.png"></p>

When selecting the image, the sharedMenuController pops up, and if i press the Action button, i would like to receive the tag containing the img tag. The problem is that using window.getSelection().innerHTML.toString() gives me an empty string and window.getSelection().getRangeAt(0).commonAncestorContainer.innerHTML.toString() what should be the p-tag, gives me the entire html.

This is my class:

@implementation UICustomWebView

+ (void)initialize
{
    [super initialize];
    UIMenuItem *itemA = [[UIMenuItem alloc] initWithTitle:@"Action" action:@selector(a:)];
    [[UIMenuController sharedMenuController] setMenuItems:[NSArray arrayWithObjects:itemA, nil]];    
}

-(BOOL)canPerformAction:(SEL)action withSender:(id)sender
{    
    if (action == @selector(defineSelection:))
    {
        return YES;
    }
    else if (action == @selector(translateSelection:))
    {
        return YES;
    }
    else if (action == @selector(copy:))
    {
        return NO;
    }
    else if ( action == @selector( a: ) )
    {
        return YES;
    }

    return [super canPerformAction:action withSender:sender];
}

-(void) a:(id)sender
{
    NSLog(@"a %@", [self stringByEvaluatingJavaScriptFromString:@"window.getSelection().getRangeAt(0).commonAncestorContainer.innerHTML.toString()"]);
}
@end

Answer 1

尝试这个：

 NSString *htmlString=[[webView stringByEvaluatingJavaScriptFromString:@"getSelectionHtml()"]mutableCopy];

Answer 2

  NSString *htmlString = [webView stringByEvaluatingJavaScriptFromString:@"document.body.innerHTML"];

Answer 3

Found out what the problem was. Apparently when putting a single object in a p-tag makes you select the entire p-tag when selecting the object. Therefor it was correct that the full html was returned since the p-tag was a child of the body. I'm using a simple custom tag around my img now and i get the values correctly.

Answer 4

Found the real answer of what i was looking for based upon the answer of Ajay:

NSString *htmlString=[[webView stringByEvaluatingJavaScriptFromString:@"getSelectionHtml()"]mutableCopy];

points to a non-native function, therefor it is useless without the javascript function that it's calling. I found a function at http://snipplr.com/view.php?codeview&id=10912 which seems to do what i require. So by injecting this JS into my page from my xsl gives me what i require to get my data.

This is the JavaScript function:

function getSelectionHTML()
        {
            var userSelection;
            if (window.getSelection) 
            {
                // W3C Ranges
                userSelection = window.getSelection ();
                // Get the range:
                if (userSelection.getRangeAt)
                    var range = userSelection.getRangeAt (0);
                else 
                {
                    var range = document.createRange ();
                    range.setStart (userSelection.anchorNode, userSelection.anchorOffset);
                    range.setEnd (userSelection.focusNode, userSelection.focusOffset);
                }
                // And the HTML:
                var clonedSelection = range.cloneContents ();
                var div = document.createElement ('div');
                div.appendChild (clonedSelection);
                return div.innerHTML;
            } 
            else if (document.selection)
            {
                // Explorer selection, return the HTML
                userSelection = document.selection.createRange ();
                return userSelection.htmlText;
            } 
            else 
            {
                return '';
            }
        };