What s the right way to decode a string that has special HTML entities in it

Question

Say I get some JSON back from a service request that looks like this          message    We amp  39 re unable to complete your request at this time       I m not sure why that apostraphe is encoded like that   amp  39    all I know is that I want to decode it   Here s one approach using jQuery that popped into my head   function decodeHtml html        return     lt div gt    html html  text        That seems  very  hacky  though  What s a better way  Is there a  right  way

User · Answer

Don   t use the DOM to do this  Using the DOM to decode HTML entities  as suggested in the currently accepted answer  leads to differences in cross-browser results   For a robust  amp  deterministic solution that decodes character references according to the algorithm in the HTML Standard  use the he library  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    Here   s how you   d use it   he decode  We amp  39 re unable to complete your request at this time        We re unable to complete your request at this time     Disclaimer  I m the author of the he library   See this Stack Overflow answer for some more info

User · Answer

This is so good answer  You can use this with angular like this    moduleDefinitions filter  sanitize      sce   function  sce        return function htmlCode            var txt   document createElement  textarea            txt innerHTML   htmlCode          return  sce trustAsHtml txt value

User · Answer

There s JS function to deal with  amp  xxxx styled entities  function at GitHub     encode decode  html text into html entity var decodeHtmlEntity   function str      return str replace   amp    d    g  function match  dec        return String fromCharCode dec             var encodeHtmlEntity   function str      var buf         for  var i str length-1 i gt  0 i--        buf unshift    amp     str i  charCodeAt         join             return buf join          var entity     amp  39640  amp  32423  amp  31243  amp  24207  amp  35774  amp  35745    var str             console log decodeHtmlEntity entity      str   console log encodeHtmlEntity str      entity      output     true    true

User · Answer

jQuery will encode and decode for you      x000D   x000D  function htmlDecode value    x000D    return     lt textarea  gt    html value  text    x000D    x000D   x000D  function htmlEncode value    x000D    return     lt textarea  gt    text value  html    x000D    x000D   lt script src  https   ajax googleapis com ajax libs jquery 1 9 1 jquery min js  gt  lt  script gt  x000D   lt script gt  x000D    document  ready function     x000D         encoded   x000D     text htmlEncode   lt img src onerror  alert 0   gt      x000D         decoded   x000D     text htmlDecode   amp lt img src onerror  alert 0   amp gt      x000D      x000D   lt  script gt  x000D   x000D   lt span gt htmlEncode   result  lt  span gt  lt br  gt  x000D   lt div id  encoded  gt  lt  div gt  x000D   lt br  gt  x000D   lt span gt htmlDecode   result  lt  span gt  lt br  gt  x000D   lt div id  decoded  gt  lt  div gt  x000D   x000D   x000D

User · Answer

If you don t want to use html dom  you could use regex  I haven t tested this  but something along the lines of   function parseHtmlEntities str        return str replace   amp    0-9  1 3    gi  function match  numStr            var num   parseInt numStr  10      read num as normal number         return String fromCharCode num                Edit   Note  this would only work for numeric html-entities  and not stuff like  oring     Edit 2   Fixed the function  some typos   test here  http   jsfiddle net Be2Bd 1

User · Answer

This is my favourite way of decoding HTML characters  The advantage of using this code is that tags are also preserved   function decodeHtml html        var txt   document createElement  textarea        txt innerHTML   html      return txt value      Example  http   jsfiddle net k65s3   Input   Entity  amp nbsp Bad attempt at XSS  lt script gt alert  new nline    lt  script gt  lt br gt    Output   Entity   Bad attempt at XSS  lt script gt alert  new nline    lt  script gt  lt br gt

User · Answer

unescape does what you re looking for  https   lodash com docs  unescape

[javascript] What's the right way to decode a string that has special HTML entities in it?

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