c# - Modifying remote JavaScripts as they load with CefSharp? -

i building custom browser part of interface remote website. gui sucks i'm doing javascript hacks make better.

currently, make modifications ui using following greasemonkey script (on firefox):

// ==userscript== // @name        winman-load // @namespace   winman // @description stuff when winman.js loads // @include     https://addons.mozilla.org/en-us/firefox/addon/greasemonkey/ // @version     1 // @grant       none // @run-at document-start // ==/userscript==  document.addeventlistener("beforescriptexecute", function(e) {     src = e.target.src;     content = e.target.text;      //console.log("src: " + src);      if (src.search("winman.js") > -1) {         console.info("============ new winman ===========\n" + src);          var newcontent = "";          $.ajax({          async: false,          type: 'get',          url: '/script/winman.js',          success: function(data) {            newcontent = data.replace('pos += currentpos;', 'pos += currentpos + 100;');            newcontent = newcontent.replace('var enable = false;', 'var enable = true;');            newcontent = newcontent.replace('var available = true;', 'var available = false;');          }         });           // stop original script         e.preventdefault();         e.stoppropagation();         unsafewindow.jquery(e.target).remove();          var script = document.createelement('script');          script.textcontent = newcontent;          (document.head || document.documentelement).appendchild(script);         script.onload = function() {             this.parentnode.removechild(this);         }       }  }); 

i want able if nature cefsharp, can modify scripts on-the-fly browser loads page.

ok figured out. create requesthandler method this:

    iresponsefilter irequesthandler.getresourceresponsefilter(iwebbrowser browsercontrol, ibrowser browser, iframe frame, irequest request, iresponse response) {         var url = new uri(request.url);          if (request.url.equals(scripttoupdate, stringcomparison.ordinalignorecase)) {              dictionary<string, string> dictionary = new dictionary<string, string>();             dictionary.add(search1, replace1);             dictionary.add(search2, replace2);              return new findreplaceresponsefilter(dictionary);         }         return null;     } 

and multiple search/replace make findreplaceresponsefilter:

using system; using system.collections.generic; using system.io; using system.linq; using system.text; using cefsharp;  namespace ceffilters {     public class findreplaceresponsefilter : iresponsefilter {         private static readonly encoding encoding = encoding.utf8;          /// <summary>         ///     portion of find string matching.         /// </summary>         private int findmatchoffset;          /// <summary>         ///     overflow output buffer.         /// </summary>         private readonly list<byte> overflow = new list<byte>();          /// <summary>         ///     number of times the string found/replaced.         /// </summary>         private int replacecount;          private dictionary<string, string> dictionary;          public findreplaceresponsefilter(dictionary<string, string> dictionary) {             this.dictionary = dictionary;         }          bool iresponsefilter.initfilter() {             return true;         }          filterstatus iresponsefilter.filter(stream datain, out long datainread, stream dataout, out long dataoutwritten) {             // data read.             datainread = datain == null ? 0 : datain.length;             dataoutwritten = 0;              // write overflow reset             if (overflow.count > 0) {                 // write overflow last time.                 writeoverflow(dataout, ref dataoutwritten);             }              // evaluate each character in input buffer. track how many characters in             // row match findstring. if findstring matched write             // replacement. otherwise, write input characters as-is.             (var = 0; < datainread; ++i) {                 var readbyte = (byte) datain.readbyte();                 var charforcomparison = convert.tochar(readbyte);                  if (replacecount < dictionary.count) {                      var replace = dictionary.elementat(replacecount);                     if (charforcomparison == replace.key[findmatchoffset]) {                         //we have match, increment counter                         findmatchoffset++;                          // if characters match string specified                         if (findmatchoffset == replace.key.length) {                             // complete match of find string. write replace string.                             writestring(replace.value, replace.value.length, dataout, ref dataoutwritten);                               // start on looking match.                             findmatchoffset = 0;                             replacecount++;                         }                         continue;                     }                     // character did not match find string.                     if (findmatchoffset > 0) {                         // write portion of find string has matched far.                         writestring(replace.key, findmatchoffset, dataout, ref dataoutwritten);                          // start on looking match.                         findmatchoffset = 0;                     }                 }                  // write current character.                 writesinglebyte(readbyte, dataout, ref dataoutwritten);             }              if (overflow.count > 0) {                 //if end overflow data we'll need return needmoredata                 // on next pass data written, next batch processed.                 return filterstatus.needmoredata;             }              // if match in-progress need more data. otherwise, we're             // done.             return findmatchoffset > 0 ? filterstatus.needmoredata : filterstatus.done;         }          private void writeoverflow(stream dataout, ref long dataoutwritten) {             // number of bytes remaining in output buffer.             var remainingspace = dataout.length - dataoutwritten;             // maximum number of bytes can write output buffer.             var maxwrite = math.min(overflow.count, remainingspace);              // write maximum portion fits in output buffer.             if (maxwrite > 0) {                 dataout.write(overflow.toarray(), 0, (int) maxwrite);                 dataoutwritten += maxwrite;             }              if (maxwrite < overflow.count) {                 // need write more bytes fit in output buffer.                  // remove bytes written                 overflow.removerange(0, (int) (maxwrite - 1));             }             else {                 overflow.clear();             }         }          private void writestring(string str, int stringsize, stream dataout, ref long dataoutwritten) {             // number of bytes remaining in output buffer.             var remainingspace = dataout.length - dataoutwritten;             // maximum number of bytes can write output buffer.             var maxwrite = math.min(stringsize, remainingspace);              // write maximum portion fits in output buffer.             if (maxwrite > 0) {                 var bytes = encoding.getbytes(str);                 dataout.write(bytes, 0, (int) maxwrite);                 dataoutwritten += maxwrite;             }              if (maxwrite < stringsize) {                 // need write more bytes fit in output buffer. store                 // remainder in overflow buffer.                 overflow.addrange(encoding.getbytes(str.substring((int) maxwrite, (int) (stringsize - maxwrite))));             }         }          private void writesinglebyte(byte data, stream dataout, ref long dataoutwritten) {             // number of bytes remaining in output buffer.             var remainingspace = dataout.length - dataoutwritten;              // write byte buffer or add overflow             if (remainingspace > 0) {                 dataout.writebyte(data);                 dataoutwritten += 1;             }             else {                 // need write more bytes fit in output buffer. store                 // remainder in overflow buffer.                 overflow.add(data);             }         }          public void dispose() {}     } } 

keep in mind iterates through left right, top bottom, make sure search , replaces in right order.