Develop Reference

Built up string causing a syntax issue

I have a c# function that builds a string which in turn is used as a hyperlink to another page. However, with some strings with single quotes it is causing a javascript error as shown here:
I'm calling the javascript function in the code behind as so
linkFullMatch.NavigateUrl = "javascript:showFullMatches(" + sb.ToString() + ")";
the javascript is on the aspx function as so:
<script>
function showFullMatches(url) {
window.open(url, "_blank", "height=344,width=1100,scrollbars=yes,resizable=yes,toolbar=no,location=no,status=no,menubar=no,left=580,top=194");
}
Any help would be greatly appreciated. Any string that doesn't have a single quote in works fine and the page link opens as requested.
Rob

You need to add an additional layer of quote marks to make the sb.ToString() value an JS string. Adjust your call like:
linkFullMatch.NavigateUrl = "javascript:showFullMatches('" + sb.ToString() + "')";
Note the additional ' marks.

Wrapping javascript concatenated html correctly with ",' and \

I'm having a bit of trouble correctly displaying a message in a webpage I am trying to create. The code I have is:
content.innerHTML += "<button 'onclick=\"likeFunction(" + feed.messages[y]._id + ")\">" + "Like(" + feed.messages[y].likesCount + ")" + "</button>"
When I inspect the element on the page source, I get this output:
<button 'onclick="like(idOfObject)">Likes(likeNumber)</button>
What I need it to look like is:
<button 'onclick="like("idOfObject")">Likes(likeNumber)</button>
I'm a bit confused on how I would add more single or double quotes and where to escape them correctly to get this desired output.

I think I see a few typos. Most noticeably with the leading ' in front of onclick. I don't think this needs to be here.
As for formatting the string, consider looking into template literals introduced in ES6.
Might look something like this:
content.innerHTML += `<button onclick="likeFunction(${idOfObjectVariable})">Likes (${likeCountVariable})</button>`
Hope this helps

You're so close! First, you need to remove the ' before onclick. If you want to add double quotes around the idOfObject, then you just need escape one double quote after likeFunction( and one double quote before )\">".
"<button onclick=\"likeFunction(\"" + feed.messages[y]._id + "\")\">"
The only problem is that when the double quotes around your variable idOfObject render, they'll correspond to the opening and closing quotes you already have for onclick. So, your solution should have single quotes inside of double quotes:
"<button onclick=\"likeFunction(\'" + feed.messages[y]._id + "\')\">"

I would have guessed what you wanted in your HTML would be:
<button onclick="like('idOfObject')">7</button>
or
<button onclick='like("idOfObject")'>7</button>
You probably do not want to quote the entire on-click attribute, just the part on the right hand side of the = .
content.innerHTML += "<button onclick=\"like('" + feed.messages[y]._id + "')\">" + ...
I'm guessing you also probably don't want something that gets displayed to the user that looks like a function all, but the result of the function call, but that is not what you were asking about.

You SHOULD NOT concatenate html manually from untrusted input (suppose someone injected malicious html code to your feed.messages[y]._id or another field). Sanitization is one of your options but it's like patching a huge hole.
You can read more about preventing those security attacks named XSS here.
Consider creating your DOM manualy with createElement API and bind your event handlers manually.
function renderButton(content, feed, y) {
function likeFunction() {
alert("LIKE" + feed.messages[y]._id);
};
var button = document.createElement("button");
var text = document.createTextNode("Like(" + feed.messages[y].likesCount + ")");
button.appendChild(text);
button.addEventListener('click', likeFunction)
content.appendChild(button);
}
Then you can just render your button with a simple function call.
renderButton(content, feed, 0)

how to embed value with an apostrophe in querystring

I have the following javascript:
tr.append("<a href='add_widget.html?id=" + data[i].id + "&pg=" + data[i].page_number + "&dest=" + data[i].dest + "&name=" + data[i].name.replace("'","\\'") + "'</a><button class='btn btn-xs btn-primary'>Edit</button> </td>");
The code in question has to do with the name field.
If I have a name like "John Doe" when I click on the hyperlink created by the above javascript, the new page's querystring has the full name.
However, if I try to pass a name like "John's stuff", the above logic creates a query string variable that looks like this:
&name=John\
How can I change the above code so that the entire string "John's stuff" is passed to the add_widget.html page?
Thanks.

replace("'","%27")
try http://meyerweb.com/eric/tools/dencoder/ it's an online URL encoder/decoder.

When you're trying to "protect" characters, you have to keep in mind what you're protecting them from. In this case, there are two interpreters you have to worry about:
You're building HTML, so you have to worry about the HTML parser;
You're building a URL, so you have to worry about how the browser and the server will parse the URL.
To deal with the first problem, you can replace the quotes with the HTML entity equivalent ('). To deal with the second, you can use encodeURIComponent().
I think you'd want to do the encodeURIComponent() call first, to avoid having the HTML entity notation get messed up. The entity notation will be gone after the HTML parser is finished with the string anyway:
function qEncode(str) {
return encodeURIComponent(str).replace(/'/g, "'");
}
To use that:
tr.append("<a href='add_widget.html?id=" +
qEncode(data[i].id) + "&pg=" +
qEncode(data[i].page_number) + "&dest=" +
qEncode(data[i].dest) + "&name=" +
qEncode(data[i].name) +
"'</a><button class='btn btn-xs btn-primary'>Edit</button> </td>"
);
Note that you could also encode double-quote characters too.
A totally different way of working around this problem would be to build the DOM content with DOM APIs. By doing that, you'd completely avoid the HTML parser, and you'd just need encodeURIComponent().

You need to think, what will be interpreting my code, so what do I need to escape for?
Your code will be interpreted by the HTML Interpreter in the browser
Your code will be interpreted as a URI
This means you need to escape/encode them in reverse order. Luckily JavaScript provides a URI encoder as encodeURIComponent, but it doesn't provide a HTML one (probably as we have DOM Methods) but it isn't too hard to implement for important characters, e.g.
function html_encode(str) {
var re_chars = /[<>'"]/g;
function replacer($0) {
return '&#' + $0.charCodeAt(0) + ';'
}
return str.replace(re_chars, replacer);
}
// example follows
html_encode('<foo bar="baz">'); // "<foo bar="baz">"
So for you,
attrib_value = html_encode(/* ... + */ encodeURIComponent(data[i].name) /* + ... */ );
For completeness,
function html_decode(str) {
var re = /&(?:#\d{1,3}|amp|quot|lt|gt|nbsp);/g, // notice extra entities
d = document.createElement('div');
function replacer($0) {
d.innerHTML = $0;
return d.textContent;
}
return str.replace(re, replacer);
}
// and an example
html_decode('<foo bar="baz">'); // "<foo bar="baz">"

Using escape(data[i].name) instead of data[i].name.replace("'","\\'"), will solve your problem.

changing links doesnt work with jquery

I have got this link:
Visit imLive.com
I want to use this code to add/change different url parameters:
$("a.sitelink_external.imlive").each(function(){
$params=getUrlVars(document.URL);
var promocode_addition='';
if('INFO'==$params['ref']){
promocode_addition='LCI';
}
$(this).attr("href", 'http://im.com/wmaster.ashx?WID=124904080515&cbname=limdeaive&LinkID=701&queryid=138&promocode=LCDIMLRV" + i + promocode_addition+"&"FRefID=" + FRefID + "&FRefP=" + FRefP + "&FRefQS=" + FRefQS');
});
The problem is that that jquery code doesnt work..I tried to move it to document ready..but it doesnt work there too..

The thing that jumps out at me is that you're mixing your double and single quotes on this line:
$(this).attr("href", 'http://im.com/wmaster.ashx?WID=124904080515&cbname=limdeaive&LinkID=701&queryid=138&promocode=LCDIMLRV" + i + promocode_addition+"&FRefID=" + FRefID + "&FRefP=" + FRefP + "&FRefQS=" + FRefQS');
Try changing them all to double quotes, and remove the extra " from after the ampersand in "&"FRefID=" - like this:
$(this).attr("href", "http://im.com/wmaster.ashx?WID=124904080515&cbname=limdeaive&LinkID=701&queryid=138&promocode=LCDIMLRV" + i + promocode_addition+"&FRefID=" + FRefID + "&FRefP=" + FRefP + "&FRefQS=" + FRefQS);
The way you had it was a single string containing stuff that looked like code. The way I've changed it is several strings and variables being concatenated together... (Note the difference with StackOverflow's syntax highlighting.)
Note also that the following code:
$params=getUrlVars(document.URL);
var promocode_addition='';
if('INFO'==$params['ref']){
promocode_addition='LCI';
}
...can be moved to before the .each() loop, since it operates only on the document and thus will produce the same results on every iteration.
(Of course there could be other problems since you reference several variables that aren't shown.)

FCKeditor, removing stuff

I am using FCKEditor in a CMS and need to post some javascript code in the editor.
This is stored in my database but it removes the + sign from this javascript code:
function _check(val){
loadFragmentInToElement('captcha_check.php?val='+val,'captcha_div','');
}
Now why would it remove the + sign?
I've tried using + and %2B but then it posts + and %2B instead of a + sign.
No, outside parties will not be able to access this to post stuff.
Edit....
The form with the editor is submitted using a javascript function
called submitform. The editor content is passed as an object called
noofeditor. I see where it 'escapes' the code retrieved from
the editor using this:
if(noofeditor){
var editorArray=noofeditor.split('::');
for (l=0;l<editorArray.length;l++){
strData += "&"+editorArray[l]+"="+escape(FCKeditorAPI.GetInstance(editorArray[l]).GetXHTML());
}
}
Is there a way to prevent it from escaping the + sign?

How about the following:
function _check(val){
var path = 'captcha_check.php?val='+val;
loadFragmentInToElement(path,'captcha_div','');
}