How to convert characters to HTML entities using plain JavaScript
With the help of bucabay and the advice to create my own function i created this one which works for me. What do you guys think, is there a better solution somewhere?
if(typeof escapeHtmlEntities == 'undefined') { escapeHtmlEntities = function (text) { return text.replace(/[\u00A0-\u2666<>\&]/g, function(c) { return '&' + (escapeHtmlEntities.entityTable[c.charCodeAt(0)] || '#'+c.charCodeAt(0)) + ';'; }); }; // all HTML4 entities as defined here: http://www.w3.org/TR/html4/sgml/entities.html // added: amp, lt, gt, quot and apos escapeHtmlEntities.entityTable = { 34 : 'quot', 38 : 'amp', 39 : 'apos', 60 : 'lt', 62 : 'gt', 160 : 'nbsp', 161 : 'iexcl', 162 : 'cent', 163 : 'pound', 164 : 'curren', 165 : 'yen', 166 : 'brvbar', 167 : 'sect', 168 : 'uml', 169 : 'copy', 170 : 'ordf', 171 : 'laquo', 172 : 'not', 173 : 'shy', 174 : 'reg', 175 : 'macr', 176 : 'deg', 177 : 'plusmn', 178 : 'sup2', 179 : 'sup3', 180 : 'acute', 181 : 'micro', 182 : 'para', 183 : 'middot', 184 : 'cedil', 185 : 'sup1', 186 : 'ordm', 187 : 'raquo', 188 : 'frac14', 189 : 'frac12', 190 : 'frac34', 191 : 'iquest', 192 : 'Agrave', 193 : 'Aacute', 194 : 'Acirc', 195 : 'Atilde', 196 : 'Auml', 197 : 'Aring', 198 : 'AElig', 199 : 'Ccedil', 200 : 'Egrave', 201 : 'Eacute', 202 : 'Ecirc', 203 : 'Euml', 204 : 'Igrave', 205 : 'Iacute', 206 : 'Icirc', 207 : 'Iuml', 208 : 'ETH', 209 : 'Ntilde', 210 : 'Ograve', 211 : 'Oacute', 212 : 'Ocirc', 213 : 'Otilde', 214 : 'Ouml', 215 : 'times', 216 : 'Oslash', 217 : 'Ugrave', 218 : 'Uacute', 219 : 'Ucirc', 220 : 'Uuml', 221 : 'Yacute', 222 : 'THORN', 223 : 'szlig', 224 : 'agrave', 225 : 'aacute', 226 : 'acirc', 227 : 'atilde', 228 : 'auml', 229 : 'aring', 230 : 'aelig', 231 : 'ccedil', 232 : 'egrave', 233 : 'eacute', 234 : 'ecirc', 235 : 'euml', 236 : 'igrave', 237 : 'iacute', 238 : 'icirc', 239 : 'iuml', 240 : 'eth', 241 : 'ntilde', 242 : 'ograve', 243 : 'oacute', 244 : 'ocirc', 245 : 'otilde', 246 : 'ouml', 247 : 'divide', 248 : 'oslash', 249 : 'ugrave', 250 : 'uacute', 251 : 'ucirc', 252 : 'uuml', 253 : 'yacute', 254 : 'thorn', 255 : 'yuml', 402 : 'fnof', 913 : 'Alpha', 914 : 'Beta', 915 : 'Gamma', 916 : 'Delta', 917 : 'Epsilon', 918 : 'Zeta', 919 : 'Eta', 920 : 'Theta', 921 : 'Iota', 922 : 'Kappa', 923 : 'Lambda', 924 : 'Mu', 925 : 'Nu', 926 : 'Xi', 927 : 'Omicron', 928 : 'Pi', 929 : 'Rho', 931 : 'Sigma', 932 : 'Tau', 933 : 'Upsilon', 934 : 'Phi', 935 : 'Chi', 936 : 'Psi', 937 : 'Omega', 945 : 'alpha', 946 : 'beta', 947 : 'gamma', 948 : 'delta', 949 : 'epsilon', 950 : 'zeta', 951 : 'eta', 952 : 'theta', 953 : 'iota', 954 : 'kappa', 955 : 'lambda', 956 : 'mu', 957 : 'nu', 958 : 'xi', 959 : 'omicron', 960 : 'pi', 961 : 'rho', 962 : 'sigmaf', 963 : 'sigma', 964 : 'tau', 965 : 'upsilon', 966 : 'phi', 967 : 'chi', 968 : 'psi', 969 : 'omega', 977 : 'thetasym', 978 : 'upsih', 982 : 'piv', 8226 : 'bull', 8230 : 'hellip', 8242 : 'prime', 8243 : 'Prime', 8254 : 'oline', 8260 : 'frasl', 8472 : 'weierp', 8465 : 'image', 8476 : 'real', 8482 : 'trade', 8501 : 'alefsym', 8592 : 'larr', 8593 : 'uarr', 8594 : 'rarr', 8595 : 'darr', 8596 : 'harr', 8629 : 'crarr', 8656 : 'lArr', 8657 : 'uArr', 8658 : 'rArr', 8659 : 'dArr', 8660 : 'hArr', 8704 : 'forall', 8706 : 'part', 8707 : 'exist', 8709 : 'empty', 8711 : 'nabla', 8712 : 'isin', 8713 : 'notin', 8715 : 'ni', 8719 : 'prod', 8721 : 'sum', 8722 : 'minus', 8727 : 'lowast', 8730 : 'radic', 8733 : 'prop', 8734 : 'infin', 8736 : 'ang', 8743 : 'and', 8744 : 'or', 8745 : 'cap', 8746 : 'cup', 8747 : 'int', 8756 : 'there4', 8764 : 'sim', 8773 : 'cong', 8776 : 'asymp', 8800 : 'ne', 8801 : 'equiv', 8804 : 'le', 8805 : 'ge', 8834 : 'sub', 8835 : 'sup', 8836 : 'nsub', 8838 : 'sube', 8839 : 'supe', 8853 : 'oplus', 8855 : 'otimes', 8869 : 'perp', 8901 : 'sdot', 8968 : 'lceil', 8969 : 'rceil', 8970 : 'lfloor', 8971 : 'rfloor', 9001 : 'lang', 9002 : 'rang', 9674 : 'loz', 9824 : 'spades', 9827 : 'clubs', 9829 : 'hearts', 9830 : 'diams', 338 : 'OElig', 339 : 'oelig', 352 : 'Scaron', 353 : 'scaron', 376 : 'Yuml', 710 : 'circ', 732 : 'tilde', 8194 : 'ensp', 8195 : 'emsp', 8201 : 'thinsp', 8204 : 'zwnj', 8205 : 'zwj', 8206 : 'lrm', 8207 : 'rlm', 8211 : 'ndash', 8212 : 'mdash', 8216 : 'lsquo', 8217 : 'rsquo', 8218 : 'sbquo', 8220 : 'ldquo', 8221 : 'rdquo', 8222 : 'bdquo', 8224 : 'dagger', 8225 : 'Dagger', 8240 : 'permil', 8249 : 'lsaquo', 8250 : 'rsaquo', 8364 : 'euro' }; }usage example:
var text = "Übergroße Äpfel mit Würmern";alert(escapeHtmlEntities (text));result:
Übergroße Äpfel mit WürmernUpdate1: Thanks bucabay again for the || - hint
Update2: Updated entity table with amp,lt,gt,apos,quot, thanksrichardtallent for the hint
Update3(in 2014): Mathias Bynens created a lib called 'he', maybe it serves your need.
All the other solutions suggested here, as well as most other JavaScript libraries that do HTML entity encoding/decoding, make several mistakes:
- They don’t implement the full list of named character references that browsers support. For example,
htmlDecode('≼')should return'≼'(i.e.'\u227C'). - They don’t support encoding astral symbols correctly. For example,
htmlEncode('𝌆')should return something like𝌆or𝌆. If an implementation returns two separate entities instead (e.g.��or��), it is broken. - They don’t support decoding astral symbols correctly.
htmlDecode('𝌆')should return'𝌆'and not'팆'(i.e.'\uD306'). - They don’t implement the character reference overrides table listed in the HTML Standard. For example,
htmlDecode('€')should return'€'(i.e.'\u20AC'). - They should perform decoding in a single pass. For example,
htmlDecode('&amp;')should return'&', not&.
For a robust solution that avoids all these issues, use a library I wrote called he for this. From its README:
he (for “HTML entities”) is a robust HTML entity encoder/decoder written in JavaScript. It supports all standardized named character references as per HTML, handles ambiguous ampersands and other edge cases just like a browser would, has an extensive test suite, and — contrary to many other JavaScript solutions — he handles astral Unicode symbols just fine. An online demo is available.
Using escape() should work with the character code range 0x00 to 0xFF (UTF-8 range).
If you go beyond 0xFF (255), such as 0x100 (256) then escape() will not work:
escape("\u0100"); // %u0100and:
text = "\u0100"; // Āhtml = escape(text).replace(/%(..)/g,"&#x$1;"); // &#xu0;100So, if you want to cover all Unicode charachacters as defined on http://www.w3.org/TR/html4/sgml/entities.html , then you could use something like:
var html = text.replace(/[\u00A0-\u00FF]/g, function(c) { return '&#'+c.charCodeAt(0)+';';});Note here the range is between: \u00A0-\u00FF.
Thats the first character code range defined in http://www.w3.org/TR/html4/sgml/entities.html which is the same as what escape() covers.
You'll need to add the other ranges you want to cover as well, or all of them.
Example: UTF-8 range with general punctuations (\u00A0-\u00FF and \u2022-\u2135)
var html = text.replace(/[\u00A0-\u00FF\u2022-\u2135]/g, function(c) { return '&#'+c.charCodeAt(0)+';';});Edit:
BTW: \u00A0-\u2666 should convert every Unicode character code not within ASCII range to HTML entities blindly:
var html = text.replace(/[\u00A0-\u2666]/g, function(c) { return '&#'+c.charCodeAt(0)+';';});