JavaScript/<text area > - javascript

alert("...");
var values = "value1
valu2part1 value2part2
value3
valu4";
alert(values);
I am assigning:
var values = "<%=Model.Values%>";
These values are stored in a database. The values are entered through a textarea
and in the database each line is seperated by \t\r.
When I take this to a JavaScript variable using:
var values = "<%=Model.Values%>";
I am getting some thing like:
var values = "value1
valu2part1 value2part2
value3
valu4";
But this is anerror. What can I do?

var values = "<%=Model.Values%>";
This is unsafe. Not only will it fail when there are newlines in the string (as JavaScript string literals cannot span multiple lines), it's also possible for a " in the value to end the string prematurely. If the value contains user-submitted data, that's a script-injection security hole (XSS).
To create JS literal syntax use a JSON serialiser. For example with JavaScriptSerializer:
var values= <%= new JavaScriptSerializer().Serialize(Model.Values) %>;
or eg Json.NET if you're on older .NET versions.

You can replace your new lines with escape sequences (\n) before outputting your string to the JS.

Related

javascript split string function not working

I am trying to split a string:
var str = "*HQ,6170930129,V1,185409,A,3132.3228,N,07424.7726,E,000.04,000,280618,FBFFBBFF,410,04,08028,40555#*HQ,6170930129,V1,185413,A,3132.3226,N,07424.7735,E,000.15,000,280618,FBFFBBFF,410,04,08028,40555"
var res = device_data.split('*');
But it's not working. it's just displaying this string
var str = "*HQ,6170930129,V1,185409,A,3132.3228,N,07424.7726,E,000.04,000,280618,FBFFBBFF,410,04,08028,40555#*HQ,6170930129,V1,185413,A,3132.3226,N,07424.7735,E,000.15,000,280618,FBFFBBFF,410,04,08028,40555"
var res = str.split('*');
console.dir(res)
,HQ,6170930129,V1,185409,A,3132.3228,N,07424.7726,E,000.04,000,280618,FBFFBBFF,410,04,08028,40555#,HQ,6170930129,V1,185413,A,3132.3226,N,07424.7735,E,000.15,000,280618,FBFFBBFF,410,04,08028,40555
Instead of creating an array with two elements.
IMHO, you want something like this:
var str = "*HQ,6170930129,V1,185409,A,3132.3228,N,07424.7726,E,000.04,000,280618,FBFFBBFF,410,04,08028,40555#*HQ,6170930129,V1,185413,A,3132.3226,N,07424.7735,E,000.15,000,280618,FBFFBBFF,410,04,08028,40555"
splitStrArr = str.split('*').filter(str => str != "")
console.log(splitStrArr)
console.log(splitStrArr[0])
console.log(splitStrArr[1])
You are getting a string with a period in the beginning because whatever you are doing leads to the result of String#split being converted to a string. String#split returns an array. An array converted to a string is of the form of element0,element1,element2 ... elements separated by commas.
The result of String#split in your case is ["",...] with 3 elements since your string begins with the character '*' you are searching, so String#split will create an empty string as the first element of the returned array. So the result is exactly as expected, and String#split is working as intended.
get rid of the first character of the string,
mystring.substr(1).split('*')
get rid of the empty strings
mystring.split('*').filter(s=>s!='')
to obtain the desired result.
You can use:
var res = str.split("#");
You can check in Javascript console in browser itself.
As a suggestion/ idea, you can always use the browser console, for example, Chrome browser, to execute simple scripts like these.
This way, you can save time, as it is easier to check your data structures, their internal data.
If you try
var res = str.split('*');
you obtain three elements:
res[0] is '' (empty string)
res[1] is 'HQ,61...'
res[2] is 'HQ,...'

Remove the javascript object variable name text from json code

I have a String variable that stores the literal text of a JavaScript object:
String jsString = "mainData = {"name":"John", "id":"12345"}"
Is there a JSON method (or any method) in Java that will remove the "mainData = " part of the string in order to leave only the JavaScript data? Something like this:
newString = someMethod(jsString);
JSONObject jsonObject = new JSONObject(newString); //newString = "{"name":"John", "id":"12345"}"
There's String#replaceFirst:
jsString = jsString.replaceFirst("^[^{]+", "");
Live Example
That will remove any characters as the start of the string prior to the first {. It makes the assumption that the string contains JSON where the outermost thing is an object (as opposed to an array or just a value), although it could readily be tweaked not to make that assumption. For instance, this version:
jsString = jsString.replaceFirst("^\\s*[A-Za-z0-9_$]+\\s*=\\s*", "");
Live Example
That removes a series of letters, numbers, _, or $, optionally surrounded by whitespace, and a following =, possibly followed by whitespace, at the beginning of the string. Now, that's not a complete list of valid JavaScript identifier characters (that list is long), but you get the idea.

retrieve attribute and value of string which is in the format of tages with attributes

I have a string which contains xml tags with some attributes,
like
var myXML='<FragmentDefinition id="frg" group="test">
<FragmentDefinition id="frg123" group="test123">';
I want to write a regular expression which gives me all the id attribute and the values
Output should be
id="frg" id="frd123"
I am very poor in REgx. I googled it for hours but i didn't find anything. for some reason i need only regular expression, not any xml readers to do my stuff
You should be able to use this regex:
/(id="[a-zA-Z0-9]*")/g
So ultimately, you can do:
var myXML= '<FragmentDefinition id="frg" group="test"><FragmentDefinition id="frg123" group="test123">';
var res = myXML.match(/(id="[a-zA-Z0-9]*")/g);
Use next source:
var result = myXML.match(/id="\w*?"/g);
Variable result will be contain array ['id="frg"', 'id="frg123"']
If you want receive string 'id="frg" id="frd123"', you can use next source:
var result = myXML.match(/id="\w*?"/g).join(" ");

remove quotes before an array list using jquery

I have been strugling with a problem, I am using
var srlisthidden = $('#hiddenroutList').val();
srlisthidden returns an array of list but in quotes "['0015','0016']"
$.each(srlisthidden, function(i, value) {
});
But because of the double quotes on the beginning of the array,it is not allowing the list to iterate even, I tried many different options to remove the double quotes like regEx and
jQuery.parseJSON('['+srlisthidden+']'), but none of them worked, Please give me solution.
Try this out:
var x = "['0015','0016']"; // The value that you are grabbing
var sol = eval(x); // This returns the value as an array of strings.
Is this what you are trying to achieve?
You can achieve it like this as well
var to_parse = "['0015','0016']";
var array = parse.replace(/\[|]|'/g, '').split(',');
JSON requires inner quotes around strings be double-quotes escaped with a backslash; the parser doesn't play nicely with single quotes.
Clean up your string with regex:
var str = srlisthidden.replace(/\'/g, "\"")
Output: ["0015","0016"] (as a string)
Then parse as JSON:
JSON.parse(str)
Output: ["0015", "0016"] (as an array)

JSON.stringify / parse oddness with quote marks

I am running into an odd little problem with parsing some JSON which has quotes in it. I am using the native JSON.stringify and JSON.parse functions to do this. If I stringify an object which an object which has quote marks in it, they are escaped as one would expect. If I then parse this back into an object, it again works fine.
The problem is occurring where I stringify, then print the object to a page, then parse the resulting string. If I try to do this, the parse function fails as stringify has only put single slashes before each of the offending quote marks.
The reason I need to achieve this is I am working on an application that dynamically loads content stored in a database as JSON strings. The strings at some point need to be printed onto the page somewhere so that the javascript can find them and build the page based on their contents. I need some way of robustly passing the object into and out of strings which will not fail if a user inputs the wrong characters!
I can solve this for the moment by inserting extra slashes into the code with a replace call, but I was wondering if there is a better way to handle this?
I have put together a couple of jsfiddles to illustrate what I am trying to describe:
http://jsfiddle.net/qwUAJ/ (Stringify then parse back)
var ob = {};
ob["number1"] = 'Number "1"';
ob["number2"] = 'Number 2';
ob["number3"] = 'Number 3';
var string = JSON.stringify(ob);
var reOb = JSON.parse('{"number1":"Number \"1\"","number2":"Number 2","number3":"Number 3"}');
$('div').html(string);
http://jsfiddle.net/a3gBf/4/ (Stringify, then print, then parse back)
// Make an object
var ob = {};
ob["number1"] = 'Number "1"';
ob["number2"] = 'Number 2';
ob["number3"] = 'Number 3';
// Turn the object into a JSON string
var string = JSON.stringify(ob);
// Printing the string outputs
// {"number1":"Number \"1\"","number2":"Number 2","number3":"Number 3"}
$('.stringified').html(string);
// Attempt to turn the printed string back into an object
var reOb = JSON.parse('{"number1":"Number \"1\"","number2":"Number 2","number3":"Number 3"}');
// This fails due to the single escaped quote marks.
Thank you for any help in advance!
This is a problem which arises from re-evaluating a String without first converting it back into a string literal, so the meaning changes if it is even still valid.
You need to consider what does '\"' as a literal actually mean? The answer is ", without the \. Why?
\" resolves to "
If you want to have \" as the result of the literal, you need to write '\\\"'
\\ resolves to \
\" resolves to "
So basically, the extra slashes are required to escape any characters with special meaning in string literals.
If you did var reOb = JSON.parse($('.stringified').html()); it would work fine as is.
Consider further
str = '\\\"\\\''; // \"\'
str = '\"\''; // "'
str = '"''; // SyntaxError: Unexpected token ILLEGAL
As far as I'm aware, JavaScript offers no native implementation to convert strings as desired, so the easiest method I know of is using a replace
function toLiteral(str) {
var dict = {'\b': 'b', '\t': 't', '\n': 'n', '\v': 'v', '\f': 'f', '\r': 'r'};
return str.replace(/([\\'"\b\t\n\v\f\r])/g, function ($0, $1) {
return '\\' + (dict[$1] || $1);
});
}
toLiteral('foo\\bar'); // "foo\\bar"
If you generate JS with PHP code you should escape the quotes in your JSON string:
//PHP code generating js code
echo "var myJSONString = \"". str_replace("\"","\\\"",$mySqlJSON)."\";";

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