Escape quotes in JavaScript

2018-12-31 18:21发布

问题:

I\'m outputting values from a database (it isn\'t really open to public entry, but it is open to entry by a user at the company -- meaning, I\'m not worried about XSS.)

I\'m trying to output a tag like this:

<a href=\"\" onclick=\"DoEdit(\'DESCRIPTION\');\">Click Me</a>

DESCRIPTION is actually a value from the database that is something like this:

Prelim Assess \"Mini\" Report

I\'ve tried replacing \" with \\\", but no matter what I try, Firefox keeps chopping off my JavaScript call after the space after the word Assess, and it is causing all sorts of issues.

I must bemissing the obvious answer, but for the life of me I can\'t figure it out.

Anyone care to point out my idiocy?

Here is the entire HTML page (it will be an ASP.NET page eventually, but in order to solve this I took out everything else but the problem code)

<html>
    <body>
        <a href=\"#\" onclick=\"DoEdit(\'Preliminary Assessment \\\"Mini\\\"\'); return false;\">edit</a>
    </body>
</html>

回答1:

You need to escape the string you are writing out into DoEdit to scrub out the double-quote characters. They are causing the onclick HTML attribute to close prematurely.

Using the JavaScript escape character, \\, isn\'t sufficient in the HTML context. You need to replace the double-quote with the proper XML entity representation, &quot;.



回答2:

&quot; would work in this particular case, as suggested before me, because of the HTML context.

However, if you want your JavaScript code to be independently escaped for any context, you could opt for the native JavaScript encoding:
\' becomes \\x27
\" becomes \\x22

So your onclick would become:
DoEdit(\'Preliminary Assessment \\x22Mini\\x22\');

This would work for example also when passing a JavaScript string as a parameter to another JavaScript method (alert() is an easy test method for this).

I am referring you to the duplicate Stack Overflow question, How do I escape a string inside JavaScript code inside an onClick handler?.



回答3:

<html>
    <body>
        <a href=\"#\" onclick=\"DoEdit(\'Preliminary Assessment &quot;Mini&quot;\'); return false;\">edit</a>
    </body>
</html>

Should do the trick.



回答4:

Folks, there is already the unescape function in JavaScript which does the unescaping for \\\":

<script type=\"text/javascript\">
    var str=\"this is \\\"good\\\"\";
    document.write(unescape(str))
</script>


回答5:

The problem is that HTML doesn\'t recognize the escape character. You could work around that by using the single quotes for the HTML attribute and the double quotes for the onclick.

<a href=\"#\" onclick=\'DoEdit(\"Preliminary Assessment \\\"Mini\\\"\"); return false;\'>edit</a>


回答6:

This is how I do it, basically str.replace(/[\\\"\"]/g, \'\\\\\"\').

var display = document.getElementById(\'output\');
var str = \'class=\"whatever-foo__input\" id=\"node-key\"\';
display.innerHTML = str.replace(/[\\\"\"]/g, \'\\\\\"\');

//will return class=\\\"whatever-foo__input\\\" id=\\\"node-key\\\"
<span id=\"output\"></span>



回答7:

If you\'re assembling the HTML in Java, you can use this nice utility class from Apache commons-lang to do all the escaping correctly:

org.apache.commons.lang.StringEscapeUtils
Escapes and unescapes Strings for Java, Java Script, HTML, XML, and SQL.



回答8:

I have done a sample one using jQuery

var descr = \'test\"inside\"outside\';
$(function(){
   $(\"#div1\").append(\'<a href=\"#\" onclick=\"DoEdit(descr);\">Click Me</a>\');       
});

function DoEdit(desc)
{
    alert ( desc );
}

And this works in Internet Explorer and Firefox.



回答9:

Please find in the below code which escapes the single quotes as part of the entered string using regular expression. It validates if the user entered string is comma separated and at the same time it even escapes any single quote(s) entered as part of the string. In order to escape single quote just enter backward slash followed by single quote like: \\’ as part of the string. I used JQuery validator for this example you can use as per your conveyance.

Valid String Examples:

\'Hello\'

\'Hello\', \'World\'

\'Hello\',\'World\'

\'Hello\',\'World\',\' \'

\'It\\\'s my world\', \'Can\\\'t enjoy this without me.\', \'Welcome, Guest\'

HTML:

<tr>
    <td>
        <label class=\"control-label\">
            String Field:
        </label>
        <div class=\"inner-addon right-addon\">
            <input type=\"text\" id=\"stringField\" 
                   name=\"stringField\"
                   class=\"form-control\"
                   autocomplete=\"off\"
                   data-rule-required=\"true\"
                   data-msg-required=\"Cannot be blank.\"
                   data-rule-commaSeparatedText=\"true\"
                   data-msg-commaSeparatedText=\"Invalid comma separated value(s).\">
        </div>
    </td>

JavaScript:

    /**
 * 
 * @param {type} param1
 * @param {type} param2
 * @param {type} param3
 */
jQuery.validator.addMethod(\'commaSeparatedText\', function(value, element) {

    if (value.length === 0) {
        return true;
    }
    var expression = new RegExp(\"^((\')([^\\\'\\\\\\\\]*(?:\\\\\\\\.[^\\\'\\\\\\\\])*)[\\\\w\\\\s,\\\\.\\\\-_\\\\[\\\\]\\\\)\\\\(]+([^\\\'\\\\\\\\]*(?:\\\\\\\\.[^\\\'\\\\\\\\])*)(\'))(((,)|(,\\\\s))(\')([^\\\'\\\\\\\\]*(?:\\\\\\\\.[^\\\'\\\\\\\\])*)[\\\\w\\\\s,\\\\.\\\\-_\\\\[\\\\]\\\\)\\\\(]+([^\\\'\\\\\\\\]*(?:\\\\\\\\.[^\\\'\\\\\\\\])*)(\'))*$\");
    return expression.test(value);
}, \'Invalid comma seperated string values.\');


回答10:

Escape whitespace as well. It sounds to me like Firefox is assuming three arguments instead of one. &nbsp; is the non-breaking space character. Even if it\'s not the whole problem, it may still be a good idea.



回答11:

You need to escape quotes with double backslashes.

This fails (produced by PHP\'s json_encode):

<script>
  var jsonString = \'[{\"key\":\"my \\\"value\\\" \"}]\';
  var parsedJson = JSON.parse(jsonString);
</script>

This works:

<script>
  var jsonString = \'[{\"key\":\"my \\\\\"value\\\\\" \"}]\';
  var parsedJson = JSON.parse(jsonString);
</script>