Search to highlight text in PDF using UIWebView

Question

I am new in ios developement I have UIWebView for displays Pdf page articles from URL. I need to search string or text and highlight.I am not able to search and highlight th

Answer 1

In my case, I have searched text from a page load in web view through text enter in Search bar & my SearchWebView.js

var uiWebview_SearchResultCount = 0;

/*!
 @method     uiWebview_HighlightAllOccurencesOfStringForElement
 @abstract   // helper function, recursively searches in elements and their child nodes
 @discussion // helper function, recursively searches in elements and their child nodes

 element    - HTML elements
 keyword    - string to search
 */

function uiWebview_HighlightAllOccurencesOfStringForElement(element,keyword) {

    if (element) {
        if (element.nodeType == 3) {        // Text node
            while (true) {
                //if (counter < 1) {
                var value = element.nodeValue;  // Search for keyword in text node
                var idx = value.toLowerCase().indexOf(keyword);

                if (idx < 0) break;             // not found, abort

                //(value.split);

                //we create a SPAN element for every parts of matched keywords
                var span = document.createElement("span");
                var text = document.createTextNode(value.substr(idx,keyword.length));
                span.appendChild(text);

                span.setAttribute("class","uiWebviewHighlight");
                span.style.backgroundColor="purple";
                span.style.color="white";

                uiWebview_SearchResultCount++;    // update the counter

                text = document.createTextNode(value.substr(idx+keyword.length));
                element.deleteData(idx, value.length - idx);
                var next = element.nextSibling;
                element.parentNode.insertBefore(span, next);
                element.parentNode.insertBefore(text, next);
                element = text;
            }
        } else if (element.nodeType == 1) { // Element node
            if (element.style.display != "none" && element.nodeName.toLowerCase() != 'select') {
                for (var i=element.childNodes.length-1; i>=0; i--) {
                    uiWebview_HighlightAllOccurencesOfStringForElement(element.childNodes[i],keyword);
                }
            }
        }
    }
}

// the main entry point to start the search
function uiWebview_HighlightAllOccurencesOfString(keyword) {
    uiWebview_RemoveAllHighlights();
    uiWebview_HighlightAllOccurencesOfStringForElement(document.body, keyword.toLowerCase());
}

// helper function, recursively removes the highlights in elements and their childs
function uiWebview_RemoveAllHighlightsForElement(element) {
    if (element) {
        if (element.nodeType == 1) {
            if (element.getAttribute("class") == "uiWebviewHighlight") {
                var text = element.removeChild(element.firstChild);
                element.parentNode.insertBefore(text,element);
                element.parentNode.removeChild(element);
                return true;
            } else {
                var normalize = false;
                for (var i=element.childNodes.length-1; i>=0; i--) {
                    if (uiWebview_RemoveAllHighlightsForElement(element.childNodes[i])) {
                        normalize = true;
                    }
                }
                if (normalize) {
                    element.normalize();
                }
            }
        }
    }
    return false;
}

// the main entry point to remove the highlights
function uiWebview_RemoveAllHighlights() {
    uiWebview_SearchResultCount = 0;
    uiWebview_RemoveAllHighlightsForElement(document.body);
}

And in my .m I have search any text enter in search bar like:

- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar
{
    [self removeAllHighlights];
    int resultCount = [self highlightAllOccurencesOfString:searchBar.text];
    if (resultCount <= 0)
    {
       alert = [[UIAlertView alloc] initWithTitle:@"No Match Found!"
                                                        message:[NSString stringWithFormat:@"No results found for this: %@", searchBar.text]
                                                       delegate:nil
                                              cancelButtonTitle:@"OK"
                                              otherButtonTitles:nil];
        [alert show];

    }
    [searchBar resignFirstResponder];
}

And my highlightAllOccurencesOfString method is working like:

- (NSInteger)highlightAllOccurencesOfString:(NSString*)str
{

    NSString *filePath  = [[NSBundle mainBundle] pathForResource:@"UIWebViewSearch" ofType:@"js" inDirectory:@""];
    NSData *fileData    = [NSData dataWithContentsOfFile:filePath];
    NSString *jsString  = [[NSMutableString alloc] initWithData:fileData encoding:NSUTF8StringEncoding];
    [webView stringByEvaluatingJavaScriptFromString:jsString];
    NSString *startSearch   = [NSString stringWithFormat:@"uiWebview_HighlightAllOccurencesOfString('%@')",str];
    [webView stringByEvaluatingJavaScriptFromString:startSearch];
    NSString *result        = [webView stringByEvaluatingJavaScriptFromString:@"uiWebview_SearchResultCount"];
    return [result integerValue];
}

And my removeAllHighlights method is:

- (void)removeAllHighlights
{
    [webView stringByEvaluatingJavaScriptFromString:@"uiWebview_RemoveAllHighlights()"];
}

Now compare all this with your situation. Hope it helps you. If any doubts then free to ask me.