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.
This question is related to
javascript
json
newline
I used this function to strip newline or other characters in data to parse JSON data:
function normalize_str($str) {
$invalid = array(
'Š'=>'S', 'š'=>'s', 'Ð'=>'Dj', 'd'=>'dj', 'Ž'=>'Z', 'ž'=>'z',
'C'=>'C', 'c'=>'c', 'C'=>'C', 'c'=>'c', 'À'=>'A', 'Á'=>'A', 'Â'=>'A', 'Ã'=>'A',
'Ä'=>'A', 'Å'=>'A', 'Æ'=>'A', 'Ç'=>'C', 'È'=>'E', 'É'=>'E', 'Ê'=>'E', 'Ë'=>'E',
'Ì'=>'I', 'Í'=>'I', 'Î'=>'I', 'Ï'=>'I', 'Ñ'=>'N', 'Ò'=>'O', 'Ó'=>'O', 'Ô'=>'O',
'Õ'=>'O', 'Ö'=>'O', 'Ø'=>'O', 'Ù'=>'U', 'Ú'=>'U', 'Û'=>'U', 'Ü'=>'U', 'Ý'=>'Y',
'Þ'=>'B', 'ß'=>'Ss', 'à'=>'a', 'á'=>'a', 'â'=>'a', 'ã'=>'a', 'ä'=>'a', 'å'=>'a',
'æ'=>'a', 'ç'=>'c', 'è'=>'e', 'é'=>'e', 'ê'=>'e', 'ë'=>'e', 'ì'=>'i', 'í'=>'i',
'î'=>'i', 'ï'=>'i', 'ð'=>'o', 'ñ'=>'n', 'ò'=>'o', 'ó'=>'o', 'ô'=>'o', 'õ'=>'o',
'ö'=>'o', 'ø'=>'o', 'ù'=>'u', 'ú'=>'u', 'û'=>'u', 'ý'=>'y', 'ý'=>'y', 'þ'=>'b',
'ÿ'=>'y', 'R'=>'R', 'r'=>'r',
"`" => "'", "´" => "'", '"' => ',', '`' => "'",
'´' => "'", '"' => '\"', '"' => "\"", '´' => "'",
"’" => "'",
"{" => "",
"~" => "", "–" => "-", "'" => "'", " " => " ");
$str = str_replace(array_keys($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']);
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"}
I encountered that problem while making a class in PHP 4 to emulate json_encode (available in PHP 5). Here's what I came up with:
class jsonResponse {
var $response;
function jsonResponse() {
$this->response = array('isOK'=>'KO', 'msg'=>'Undefined');
}
function set($isOK, $msg) {
$this->response['isOK'] = ($isOK) ? 'OK' : 'KO';
$this->response['msg'] = htmlentities($msg);
}
function setData($data=null) {
if(!is_null($data))
$this->response['data'] = $data;
elseif(isset($this->response['data']))
unset($this->response['data']);
}
function send() {
header('Content-type: application/json');
echo '{"isOK":"' . $this->response['isOK'] . '","msg":' . $this->parseString($this->response['msg']);
if(isset($this->response['data']))
echo ',"data":' . $this->parseData($this->response['data']);
echo '}';
}
function parseData($data) {
if(is_array($data)) {
$parsed = array();
foreach ($data as $key=>$value)
array_push($parsed, $this->parseString($key) . ':' . $this->parseData($value));
return '{' . implode(',', $parsed) . '}';
}
else
return $this->parseString($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.
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"":""" & escape(RS_Temp("textField")) & """}"
In the browser:
document.getElementById("text1").value = unescape(jsonObject.field1)
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
)
var dataObj = {"count" : 1, "stack" : "sometext\n\n"};_x000D_
_x000D_
console.log(dataObj);
_x000D_
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 charactersU+0000
toU+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.\" }";
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 < len; i += 1)
{
c = s[i];
if ((c == '\\') || (c == '"') || (c == '>'))
{
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 < ' ')
{
//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();
}
JSON.stringify
JSON.stringify(`{
a:"a"
}`)
would convert the above string to
"{ \n a:\"a\"\n }"
as mentioned here
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.
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
<p style={{whiteSpace: 'pre-line'}}>my json text goes here \n\n</p>
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.
Source: Stackoverflow.com