用 onerror 获取错误信

这个东西是在线写 js 脚本的时候，用来即时查错的东西！

也就是，当发现所编写的脚本有问题的时候会有相应的提示，并且在源代码框中高亮标示出错行，方便除错！

运行代码框
<HTML> <HEAD> <TITLE>Debug Textarea</TITLE> <meta http-equiv='Content-Type' content='text/html; charset=gb2312'> </HEAD> <style> * { font-size: 12px } body { margin: 10px; padding: 0px } table.list{ cursor: default; border:1px solid #cccccc background-color: #cccccc; border-collapse: collapse; border-Color: #cccccc; } </style> <script language="javascript"> // Coded by windy_sk <windy_sk@126.com> 20040205 function reportError(msg,url,line) { var str = "You have found an error as below: \n\n"; str += "Err: " + msg + " on line: " + line; alert(str); return true; } window.onerror = reportError; document.onkeydown = function() { if(event.ctrlKey){ switch(event.keyCode) { case 82: //r runcode(); break; case 83: //s savecode(); break; case 71: //g goto(prompt('Please input the line number', '1')); break; case 65: //a document.execCommand("SelectAll"); break; case 67: //c document.execCommand("Copy"); break; case 88: //x document.execCommand("Cut"); break; case 86: //v document.execCommand("Paste"); break; case 90: //z document.execCommand("Undo"); break; case 89: //y document.execCommand("Redo"); break; default: break; } event.keyCode = 0; event.returnValue = false; } return; } function show_ln(){ var txt_ln = document.getElementById('txt_ln'); var txt_main = document.getElementById('txt_main'); txt_ln.scrollTop = txt_main.scrollTop; while(txt_ln.scrollTop != txt_main.scrollTop) { txt_ln.value += (i++) + '\n'; txt_ln.scrollTop = txt_main.scrollTop; } return; } function editTab(){ var code, sel, tmp, r; event.returnValue = false; sel =event.srcElement.document.selection.createRange(); r = event.srcElement.createTextRange(); switch (event.keyCode){ case (8) : if (!(sel.getClientRects().length > 1)){ event.returnValue = true; return; } code = sel.text; tmp = sel.duplicate(); tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top); if(sel.parentElement() != tmp.parentElement()) return;; sel.setEndPoint('startToStart', tmp); sel.text = sel.text.replace(/^\t/gm, ''); code = code.replace(/^\t/gm, '').replace(/\r\n/g, '\r'); r.findText(code); r.select(); break; case (9) : if (sel.getClientRects().length > 1){ code = sel.text; tmp = sel.duplicate(); tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top); if(sel.parentElement() != tmp.parentElement()) return; sel.setEndPoint('startToStart', tmp); sel.text = '\t'+sel.text.replace(/\r\n/g, '\r\t'); code = code.replace(/\r\n/g, '\r\t'); r.findText(code); r.select(); }else{ sel.text = '\t'; sel.select(); } break case (13) : tmp = sel.duplicate(); tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top); if(sel.parentElement() != tmp.parentElement()) return; tmp.setEndPoint('endToEnd', sel); sel.text = '\r\n' + tmp.text.replace(tmp.text.replace(/^[\t ]+/g, ""),""); sel.select(); break; default : event.returnValue = true; break; } return; } function runcode() { var str = document.getElementById("txt_main").value; var code_win = window.open('about:blank'); code_win.document.open(); code_win.document.writeln("<script>"); code_win.document.writeln("function reportError(msg,url,line){\nline-=14;\nvar str='You have found an error as below: \\n\\n';\nstr+='Err: '+msg+' on line: '+(line);\nalert(str);\nopener.goto(line);\nopener.focus();\nwindow.onerror=null;\nsetTimeout('self.close()',10);\nreturn true;\n}"); code_win.document.writeln("window.onerror = reportError;"); code_win.document.writeln("<\/script>"); code_win.document.writeln(str); code_win.document.close(); return; } function savecode() { var str = document.getElementById("txt_main").value; var code_win = window.open('about:blank','_blank','top=10000'); code_win.document.open(); code_win.document.writeln(str); code_win.document.close(); code_win.document.execCommand('saveas','','code.html'); code_win.close(); return; } function goto(ln) { if(!/^\d+$/.test(ln) || ln==0) return; var obj = document.getElementById("txt_main"); var rng = obj.createTextRange(); var arr = obj.value.split(/\n/); if(ln>arr.length) ln = arr.length; var str_tmp = ""; for(var i=0; i<ln-1; i++) { str_tmp += arr[i]; } rng.moveStart('character',str_tmp.length); str_tmp = ""; for(i=ln; i<arr.length; i++) { str_tmp += arr[i]; } rng.moveEnd('character',-str_tmp.length); rng.select(); return; } window.onload = function() {document.getElementById("txt_main").value = "<script>\nalert(')\n<\/script>";} </script> <BODY> <table width='600' class='list' border='1' bgcolor='#eeeeee' bordercolorlight='#000000' bordercolordark='#FFFFFF' cellpadding='0' cellspacing='0'> <tr bgcolor='#cccccc'> <td colspan='2' height='20' align='center'><b>Debug Textarea</b></td> </tr> <tr> <td colspan='2'> <table width='95%' border='0' align='center' > <tr> <td align='center'><br /> <textarea id='txt_ln' name='content' rows='10' style='width:40px;overflow:hidden;height:200px;border-right:0px;text-align:right;line-height:14px' onselectstart='this.nextSibling.focus();return false' readonly>