Convert special characters to HTML in Javascript

问题:

Does any one know how to convert special characters to HTML in Javascript?

Example:

• & (ampersand) becomes &amp.
• \" (double quote) becomes &quot when ENT_NOQUOTES is not set.
• \' (single quote) becomes &#039 only when ENT_QUOTES is set.
• < (less than) becomes &lt.
• > (greater than) becomes &gt.

回答1:

You need a function that does something like

return mystring.replace(/&/g, \"&amp;\").replace(/>/g, \"&gt;\").replace(/</g, \"&lt;\").replace(/\"/g, \"&quot;\");

But taking into account your desire for different handling of single/double quotes.

回答2:

The best way in my opinion is to use the browser\'s inbuilt HTML escape functionality to handle many of the cases. To do this simply create a element in the DOM tree and set the innerText of the element to your string. Then retrieve the innerHTML of the element. The browser will return an HTML encoded string.

function HtmlEncode(s)
{
  var el = document.createElement(\"div\");
  el.innerText = el.textContent = s;
  s = el.innerHTML;
  return s;
}

Test run:

alert(HtmlEncode(\'&;\\\'><\"\'));

Output:

&;\'><\"

This method of escaping HTML is also used by the Prototype JS library though differently from the simplistic sample I have given.

Note: You will still need to escape quotes (double and single) yourself. You can use any of the methods outlined by others here.

回答3:

This generic function encodes every non alphabetic character to its htmlcode (numeric):

function HTMLEncode(str) {
    var i = str.length,
        aRet = [];

    while (i--) {
        var iC = str[i].charCodeAt();
        if (iC < 65 || iC > 127 || (iC>90 && iC<97)) {
            aRet[i] = \'&#\'+iC+\';\';
        } else {
            aRet[i] = str[i];
        }
    }
    return aRet.join(\'\');
}

回答4:

From Mozilla ...

Note that charCodeAt will always return a value that is less than 65,536. This is because the higher code points are represented by a pair of (lower valued) \"surrogate\" pseudo-characters which are used to comprise the real character. Because of this, in order to examine or reproduce the full character for individual characters of value 65,536 and above, for such characters, it is necessary to retrieve not only charCodeAt(i), but also charCodeAt(i+1) (as if examining/reproducing a string with two >letters).

The Best Solution

/**
 * (c) 2012 Steven Levithan <http://slevithan.com/>
 * MIT license
 */
if (!String.prototype.codePointAt) {
    String.prototype.codePointAt = function (pos) {
        pos = isNaN(pos) ? 0 : pos;
        var str = String(this),
            code = str.charCodeAt(pos),
            next = str.charCodeAt(pos + 1);
        // If a surrogate pair
        if (0xD800 <= code && code <= 0xDBFF && 0xDC00 <= next && next <= 0xDFFF) {
            return ((code - 0xD800) * 0x400) + (next - 0xDC00) + 0x10000;
        }
        return code;
    };
}

/**
 * Encodes special html characters
 * @param string
 * @return {*}
 */
function html_encode(string) {
    var ret_val = \'\';
    for (var i = 0; i < string.length; i++) { 
        if (string.codePointAt(i) > 127) {
            ret_val += \'&#\' + string.codePointAt(i) + \';\';
        } else {
            ret_val += string.charAt(i);
        }
    }
    return ret_val;
}

Usage example:

html_encode(\"✈\");

回答5:

Create a function that uses string replace

function convert(str)
{
  str = str.replace(/&/g, \"&\");
  str = str.replace(/>/g, \">\");
  str = str.replace(/</g, \"&lt;\");
  str = str.replace(/\"/g, \"&quot;\");
  str = str.replace(/\'/g, \"&#039;\");
  return str;
}

回答6:

function char_convert() {

    var chars = [\"©\",\"Û\",\"®\",\"ž\",\"Ü\",\"Ÿ\",\"Ý\",\"$\",\"Þ\",\"%\",\"¡\",\"ß\",\"¢\",\"à\",\"£\",\"á\",\"À\",\"¤\",\"â\",\"Á\",\"¥\",\"ã\",\"Â\",\"¦\",\"ä\",\"Ã\",\"§\",\"å\",\"Ä\",\"¨\",\"æ\",\"Å\",\"©\",\"ç\",\"Æ\",\"ª\",\"è\",\"Ç\",\"«\",\"é\",\"È\",\"¬\",\"ê\",\"É\",\"­\",\"ë\",\"Ê\",\"®\",\"ì\",\"Ë\",\"¯\",\"í\",\"Ì\",\"°\",\"î\",\"Í\",\"±\",\"ï\",\"Î\",\"²\",\"ð\",\"Ï\",\"³\",\"ñ\",\"Ð\",\"´\",\"ò\",\"Ñ\",\"µ\",\"ó\",\"Õ\",\"¶\",\"ô\",\"Ö\",\"·\",\"õ\",\"Ø\",\"¸\",\"ö\",\"Ù\",\"¹\",\"÷\",\"Ú\",\"º\",\"ø\",\"Û\",\"»\",\"ù\",\"Ü\",\"@\",\"¼\",\"ú\",\"Ý\",\"½\",\"û\",\"Þ\",\"€\",\"¾\",\"ü\",\"ß\",\"¿\",\"ý\",\"à\",\"‚\",\"À\",\"þ\",\"á\",\"ƒ\",\"Á\",\"ÿ\",\"å\",\"„\",\"Â\",\"æ\",\"…\",\"Ã\",\"ç\",\"†\",\"Ä\",\"è\",\"‡\",\"Å\",\"é\",\"ˆ\",\"Æ\",\"ê\",\"‰\",\"Ç\",\"ë\",\"Š\",\"È\",\"ì\",\"‹\",\"É\",\"í\",\"Œ\",\"Ê\",\"î\",\"Ë\",\"ï\",\"Ž\",\"Ì\",\"ð\",\"Í\",\"ñ\",\"Î\",\"ò\",\"‘\",\"Ï\",\"ó\",\"’\",\"Ð\",\"ô\",\"“\",\"Ñ\",\"õ\",\"”\",\"Ò\",\"ö\",\"•\",\"Ó\",\"ø\",\"–\",\"Ô\",\"ù\",\"—\",\"Õ\",\"ú\",\"˜\",\"Ö\",\"û\",\"™\",\"×\",\"ý\",\"š\",\"Ø\",\"þ\",\"›\",\"Ù\",\"ÿ\",\"œ\",\"Ú\"]; 
    var codes = [\"©\",\"Û\",\"®\",\"ž\",\"Ü\",\"Ÿ\",\"Ý\",\"$\",\"Þ\",\"%\",\"¡\",\"ß\",\"¢\",\"à\",\"£\",\"á\",\"À\",\"¤\",\"â\",\"Á\",\"¥\",\"ã\",\"Â\",\"¦\",\"ä\",\"Ã\",\"§\",\"å\",\"Ä\",\"¨\",\"æ\",\"Å\",\"©\",\"ç\",\"Æ\",\"ª\",\"è\",\"Ç\",\"«\",\"é\",\"È\",\"¬\",\"ê\",\"É\",\"­\",\"ë\",\"Ê\",\"®\",\"ì\",\"Ë\",\"¯\",\"í\",\"Ì\",\"°\",\"î\",\"Í\",\"±\",\"ï\",\"Î\",\"²\",\"ð\",\"Ï\",\"³\",\"ñ\",\"Ð\",\"´\",\"ò\",\"Ñ\",\"µ\",\"ó\",\"Õ\",\"¶\",\"ô\",\"Ö\",\"·\",\"õ\",\"Ø\",\"¸\",\"ö\",\"Ù\",\"¹\",\"÷\",\"Ú\",\"º\",\"ø\",\"Û\",\"»\",\"ù\",\"Ü\",\"@\",\"¼\",\"ú\",\"Ý\",\"½\",\"û\",\"Þ\",\"€\",\"¾\",\"&#252\",\"ß\",\"¿\",\"ý\",\"à\",\"‚\",\"À\",\"þ\",\"á\",\"ƒ\",\"Á\",\"ÿ\",\"å\",\"„\",\"Â\",\"æ\",\"…\",\"Ã\",\"ç\",\"†\",\"Ä\",\"è\",\"‡\",\"Å\",\"é\",\"ˆ\",\"Æ\",\"ê\",\"‰\",\"Ç\",\"ë\",\"Š\",\"È\",\"ì\",\"‹\",\"É\",\"í\",\"Œ\",\"Ê\",\"î\",\"Ë\",\"ï\",\"Ž\",\"Ì\",\"ð\",\"Í\",\"ñ\",\"Î\",\"ò\",\"‘\",\"Ï\",\"ó\",\"’\",\"Ð\",\"ô\",\"“\",\"Ñ\",\"õ\",\"”\",\"Ò\",\"ö\",\"•\",\"Ó\",\"ø\",\"–\",\"Ô\",\"ù\",\"—\",\"Õ\",\"ú\",\"˜\",\"Ö\",\"û\",\"™\",\"×\",\"ý\",\"š\",\"Ø\",\"þ\",\"›\",\"Ù\",\"ÿ\",\"œ\",\"Ú\"];

    for(x=0; x<chars.length; x++){
        for (i=0; i<arguments.length; i++){
            arguments[i].value = arguments[i].value.replace(chars[x], codes[x]);
        }
    }
 }

char_convert(this);

回答7:

function ConvChar( str ) {
  c = {\'<\':\'&lt;\', \'>\':\'&gt;\', \'&\':\'&amp;\', \'\"\':\'&quot;\', \"\'\":\'&#039;\',
       \'#\':\'&#035;\' };
  return str.replace( /[<&>\'\"#]/g, function(s) { return c[s]; } );
}

alert( ConvChar(\'<-\"-&-\"->-<-\\\'-#-\\\'->\') );

Result:

<-"-&-"->-<-'-#-'->

In testarea tag:

<-\"-&-\"->-<-\'-#-\'->

If you\'ll just change a little chars in long code...

回答8:

In a PRE tag -and in most other HTML tags- plain text for a batch file that uses the output redirection characters (< and >) will break the HTML, but here is my tip: anything goes in a TEXTAREA element -it will not break the HTML, mainly because we are inside a control instanced and handled by the OS, and therefore its content are not being parsed by the HTML engine.

As an example, say I want to highlight the syntax of my batch file using javascript. I simply paste the code in a textarea without worrying about the HTML reserved characters, and have the script process the innerHTML property of the textarea, which evaluates to the text with the HTML reserved characters replaced by their corresponding ISO-8859-1 entities.

Browsers will escape special characters automatically when you retrieve the innerHTML (and outerHTML) property of an element. Using a textarea (and who knows, maybe an input of type text) just saves you from doing the conversion (manually or through code).

I use this trick to test my syntax highlighter, and when I\'m done authoring and testing, I simply hide the textarea from view.

回答9:

As was mentioned by dragon the cleanest way to do it is with jQuery:

function HtmlEncode(s) {
    return $(\'<div>\').text(s).html();
}

function HtmlDecode(s) {
    return $(\'<div>\').html(s).text();
}

回答10:

a workaround:

var temp = $(\"div\").text(\"<\");
var afterEscape = temp.html(); // afterEscape == \"&lt;\"

回答11:

var swapCodes   = new Array(8211, 8212, 8216, 8217, 8220, 8221, 8226, 8230, 8482, 169, 61558, 8226, 61607);
var swapStrings = new Array(\"--\", \"--\", \"\'\",  \"\'\",  \'\"\',  \'\"\',  \"*\",  \"...\", \"™\", \"©\", \"•\", \"•\", \"•\");

var TextCheck = {
    doCWBind:function(div){
        $(div).bind({
            bind:function(){
                TextCheck.cleanWord(div);
            },
            focus:function(){
                TextCheck.cleanWord(div);
            },
            paste:function(){
                TextCheck.cleanWord(div);
            }
        }); 
    },
    cleanWord:function(div){
        var output = $(div).val();
        for (i = 0; i < swapCodes.length; i++) {
            var swapper = new RegExp(\"\\\\u\" + swapCodes[i].toString(16), \"g\");
            output = output.replace(swapper, swapStrings[i]);
        }
        $(div).val(output);
    }
}

Another one that we use now that works. One above I have it calling a script instead and returns the converted code. Only good on small textareas (meaning not a full on article/blog ect...)

---

For Above. Works on most chars.

var swapCodes   = new Array(8211, 8212, 8216, 8217, 8220, 8221, 8226, 8230, 8482, 61558, 8226, 61607,161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 338, 339, 352, 353, 376, 402);
var swapStrings = new Array(\"--\", \"--\", \"\'\",  \"\'\",  \'\"\',  \'\"\',  \"*\",  \"...\", \"™\", \"•\", \"•\", \"•\", \"¡\", \"¢\", \"£\", \"¤\", \"¥\", \"¦\", \"§\", \"¨\", \"©\", \"ª\", \"«\", \"¬\", \"­\", \"®\", \"¯\", \"°\", \"±\", \"²\", \"³\", \"´\", \"µ\", \"¶\", \"·\", \"¸\", \"¹\", \"º\", \"»\", \"¼\", \"½\", \"¾\", \"¿\", \"À\", \"Á\", \"Â\", \"Ã\", \"Ä\", \"Å\", \"Æ\", \"Ç\", \"È\", \"É\", \"Ê\", \"Ë\", \"Ì\", \"Í\", \"Î\", \"Ï\", \"Ð\", \"Ñ\", \"Ò\", \"Ó\", \"Ô\", \"Õ\", \"Ö\", \"×\", \"Ø\", \"Ù\", \"Ú\", \"Û\", \"Ü\", \"Ý\", \"Þ\", \"ß\", \"à\", \"á\", \"â\", \"ã\", \"ä\", \"å\", \"æ\", \"ç\", \"è\", \"é\", \"ê\", \"ë\", \"ì\", \"í\", \"î\", \"ï\", \"ð\", \"ñ\", \"ò\", \"ó\", \"ô\", \"õ\", \"ö\", \"÷\", \"ø\", \"ù\", \"ú\", \"û\", \"ü\", \"ý\", \"þ\", \"ÿ\", \"Œ\", \"œ\", \"Š\", \"š\", \"Ÿ\", \"ƒ\");

---

I create a javascript file that has a lot of functionality including the above. http://www.neotropicsolutions.com/JSChars.zip

All files needed are included. I added jQuery 1.4.4. Simply because I saw issues in other versions, yet to try them out.

Requires: jQuery & jQuery Impromptu from: http://trentrichardson.com/Impromptu/index.php

1. Word Count
2. Character Conversion
3. Checks to ensure this is not passed: \"notsomeverylongstringmissingspaces\"
4. Checks to make sure ALL IS NOT ALL UPPERCASE.
5. Strip HTML

    // Word Counter
    $.getScript(\'js/characters.js\',function(){
            $(\'#adtxt\').bind(\"keyup click blur focus change paste\",
                function(event){
                    TextCheck.wordCount(30, \"#adtxt\", \"#adtxt_count\", event);
            });
            $(\'#adtxt\').blur(
                function(event){
                    TextCheck.check_length(\'#adtxt\'); // unsures properly spaces-not one long word
                    TextCheck.doCWBind(\'#adtxt\');// char conversion
            });

            TextCheck.wordCount(30, \"#adtxt\", \"#adtxt_count\", false);
        });

    //HTML
    <textarea name=\"adtxt\" id=\"adtxt\" rows=\"10\" cols=\"70\" class=\"wordCount\"></textarea>
<div id=\"adtxt_count\" class=\"clear\"></div>

    // Just Character Conversions:
    TextCheck.doCWBind(\'#myfield\');

    // Run through form fields in a form for case checking.
    // Alerts user when field is blur\'d.
    var labels = new Array(\"Brief Description\",\"Website URL\",\"Contact Name\",\"Website\",\"Email\",\"Linkback URL\");
    var checking = new Array(\"descr\",\"title\",\"fname\",\"website\",\"email\",\"linkback\");
    TextCheck.check_it(checking,labels);

    // Extra security to check again, make sure form is not submitted
    var pass = TextCheck.validate(checking,labels);
    if(pass){
        //do form actions
    }


    //Strip HTML
    <textarea name=\"adtxt\" id=\"adtxt\" rows=\"10\" cols=\"70\" onblur=\"TextCheck.stripHTML(this);\"></textarea>

回答12:

 <!doctype html>
    <html lang=\"en\">
    <head>
      <meta charset=\"utf-8\">
      <title>html</title>  
      <script>
      $(function() {   
      document.getElementById(\'test\').innerHTML = \"&amp;\";
      });

      </script>
    </head>
    <body>
    <div id=\"test\"></div>
    </body>
    </html>

you can simply convert special characters to html using above code.

回答13:

If you need support for all standardized named character references, unicode and ambiguous ampersands, the he library is the only 100% reliable solution I\'m aware of!

---

Example use

he.encode(\'foo © bar ≠ baz