How do I handle newlines in JSON

Question

I ve generated some JSON and I m trying to pull it into an object in JavaScript  I keep getting errors  Here s what I have   var data      count    1   stack     sometext n n     var dataObj   eval     data         This gives me an error    unterminated string literal   With JSON parse data   I see similar error messages   Unexpected token    in Chrome  and  unterminated string literal  in Firefox and IE   When I take out the  n after sometext the error goes away in both cases  I can t seem to figure out why the  n makes eval and JSON parse fail

User · Answer

According to the specification  http   www ecma-international org publications files ECMA-ST ECMA-404 pdf      A string is a sequence of Unicode code points wrapped with quotation marks      U 0022   All characters may be placed within the quotation marks except for the     characters that must be escaped  quotation mark  U 0022   reverse solidus      U 005C   and the control characters U 0000 to U 001F  There are two-character     escape sequence representations of some characters    So you can t pass 0x0A or 0x0C codes directly  It is forbidden  The specification suggests to use escape sequences for some well-defined codes from U 0000 to U 001F     f represents the form feed character  U 000C    n represents the line feed character  U 000A     As most of programming languages uses   for quoting  you should escape the escape syntax  double-escape - once for language platform  once for JSON itself    jsonStr        name      Multi  nline

User · Answer

I encountered that problem while making a class in PHP nbsp 4 to emulate json encode  available in PHP nbsp 5   Here s what I came up with   class jsonResponse       var  response       function jsonResponse              this- gt response   array  isOK   gt  KO    msg   gt  Undefined               function set  isOK   msg             this- gt response  isOK       isOK     OK     KO            this- gt response  msg     htmlentities  msg              function setData  data null            if  is null  data                this- gt response  data      data          elseif isset  this- gt response  data                 unset  this- gt response  data                function send             header  Content-type  application json            echo    isOK        this- gt response  isOK         msg       this- gt parseString  this- gt response  msg             if isset  this- gt response  data                 echo    data       this- gt parseData  this- gt response  data             echo                 function parseData  data            if is array  data                  parsed   array                foreach   data as  key  gt  value                  array push  parsed   this- gt parseString  key           this- gt parseData  value                return       implode       parsed                           else             return  this- gt parseString  data              function parseString  string                 string   str replace                string                string   str replace              string                string   str replace                 string                string   str replace   b      b    string                string   str replace   t      t    string                string   str replace   n      n    string                string   str replace   f      f    string                string   str replace   r      r    string                string   str replace   u      u    string               return      string                I followed the rules mentioned here  I only used what I needed  but I figure that you can adapt it to your needs in the language your are using  The problem in my case wasn t about newlines as I originally thought  but about the   not being escaped  I hope this prevent someone else from the little headache I had figuring out what I did wrong

User · Answer

JSON stringify   JSON stringify       a  a        would convert the above string to      n      a   a   n         as mentioned here  json stringify     This function adds double quotes at the beginning and end of the input string and escapes special JSON characters  In particular  a newline is replaced by the  n character  a tab is replaced by the  t character  a backslash is replaced by two backslashes    and a backslash is placed before each quotation mark

User · Answer

You will need to have a function which replaces  n to   n in case data is not a string literal   function jsonEscape str         return str replace   n g       n   replace   r g       r   replace   t g       t       var data      count    1   stack     sometext n n     var dataObj   JSON parse jsonEscape data      Resulting dataObj will be  Object  count  1  stack   sometext n n

User · Answer

You might want to look into this C  function to escape the string   http   www aspcode net C-encode-a-string-for-JSON-JavaScript aspx  public static string Enquote string s           if  s    null    s Length    0                   return                     char         c       int          i       int          len   s Length       StringBuilder sb   new StringBuilder len   4        string       t        sb Append            for  i   0  i  lt  len  i    1                   c   s i            if   c              c             c      gt                             sb Append                     sb Append c                       else if  c      b                sb Append    b             else if  c      t                sb Append    t             else if  c      n                sb Append    n             else if  c      f                sb Append    f             else if  c      r                sb Append    r             else                         if  c  lt                                          t    000    Integer toHexString c                    string t   new string c 1                    t    000    int Parse tmp System Globalization NumberStyles HexNumber                    sb Append    u    t Substring t Length - 4                                 else                                  sb Append c                                         sb Append            return sb ToString

User · Answer

As I understand you question  it is not about parsing JSON because you can copy-paste your JSON into your code directly - so if this is the case then just copy your JSON direct to dataObj variable without wrapping it with single quotes   tip  eval  evil     x000D   x000D  var dataObj     count    1   stack     sometext n n    x000D   x000D  console log dataObj   x000D   x000D   x000D

User · Answer

well  it is not really necessary to create a function for this when it can be done simply with 1 CSS class  just wrap your text around this class and see the magic  D   lt p style   whiteSpace   pre-line    gt my json text goes here  n n lt  p gt   note  because you will always present your text in frontend with HTML you can add the style   whiteSpace   pre-line    to any tag  not just the p tag

User · Answer

I guess this is what you want   var data      count    1   stack     sometext  n  n        You need to escape the     in your string  turning it into a double-      otherwise it will become a newline in the JSON source  not the JSON data

User · Answer

I used this function to strip newline or other characters in data to parse JSON data   function normalize str  str          invalid   array                gt  S         gt  s          gt  Dj    d   gt  dj         gt  Z         gt  z            C   gt  C    c   gt  c     C   gt  C     c   gt  c          gt  A         gt  A         gt  A         gt  A                 gt  A         gt  A          gt  A          gt  C          gt  E         gt  E         gt  E         gt  E                 gt  I         gt  I          gt  I          gt  I          gt  N         gt  O         gt  O         gt  O                 gt  O         gt  O          gt  O          gt  U          gt  U         gt  U         gt  U         gt  Y                 gt  B         gt  Ss         gt  a          gt  a          gt  a         gt  a         gt  a         gt  a                 gt  a         gt  c          gt  e          gt  e          gt  e         gt  e         gt  i         gt  i                 gt  i         gt  i          gt  o          gt  n          gt  o         gt  o         gt  o         gt  o                 gt  o         gt  o          gt  u          gt  u          gt  u         gt  y         gt  y         gt  b                 gt  y    R   gt  R     r   gt  r                 gt              gt              gt              gt                      gt             gt              gt               gt                 amp acirc           gt                     gt                    gt               gt   -          gt                  gt              str   str replace array keys  invalid   array values  invalid    str         remove   array   n     r n     r         str   str replace  remove     n   trim  str            str   htmlentities  str  ENT QUOTES        return htmlspecialchars  str      echo normalize str  lst  address

User · Answer

You could just escape your string on the server when writing the value of the JSON field and unescape it when retrieving the value in the client browser  for instance   The JavaScript implementation of all major browsers have the unescape command   Example   On the server   response write     field1        amp  escape RS Temp  textField     amp          In the browser    document getElementById  text1   value   unescape jsonObject field1

[javascript] How do I handle newlines in JSON?

Examples related to javascript

Examples related to json

Examples related to newline