JSON2 Error / Conflict with another script - asp.net-mvc

I am using the JSON2 library in order to use JSON.stringify to send some JSON data to my MVC controller.
When I include another script in my view (Telerik MVC) I start to get script conflicts when using IE7.
When I click the refresh button in the grid, I get the following error:
Line: 191
Error: Object doesn't support this property or method
String.prototype.toJSON =
Number.prototype.toJSON =
Boolean.prototype.toJSON = function (key) {
return this.valueOf();
};
The error occurs on the following line specifically:
return this.valueOf();
Does anyone have any insight into why this conflict is occurring and how to resolve it? Specifically, why would this work in IE8/Chrome but fail in IE7. What would cause the error? Are both scripts trying to define the same method and that's why it is failing or is it impossible to tell without digging through tons of code?
Edit:
This is the json2.js library I am speaking of: https://github.com/douglascrockford/JSON-js

Probably the reply is too late, but I thought it's worth replying as this might save some valuable lives ;)
The JSON2 script won't initialize/extend the JSON object if there is an existing implementation(Native or Included). However if the JSON object does not exist, the script will create that object and attach few methods to it (JSON.stringify and JSON.parse to be precise). However in order to make those methods to work, there are other objects (like Date, String, Number and Boolean objects) which need to be extended to support certain methods (like toJSON method). The JSON2 script takes care of extending the required objects as well.
Now coming to the specific issue here (Telerik MVC). I faced the same problem while working with Telerik for one of the Projects. However I was able to trace it. The probable cause is the conflict between Telerik scripts and the current JSON2 script. The Date and Boolean Objects' toJSON method somehow conflicts with Telerik's implmentation of the same method for those two objects which breaks the Telerik script at some places. I have modified the JSON2 library for a more robust check which doesn't fail in any scenario (even on use of Telerik MVC on the page). I have tested the script and it works fine for me, however in case someone finds any further conflicts, please reply back.
var JSON;
if (!JSON) {
JSON = {};
}
(function () {
'use strict';
function f(n) {
// Format integers to have at least two digits.
return n < 10 ? '0' + n : n;
}
if (typeof Date.prototype.toJSON !== 'function') {
Date.prototype.toJSON = function (key) {
return isFinite(this.valueOf())
? this.getUTCFullYear() + '-' +
f(this.getUTCMonth() + 1) + '-' +
f(this.getUTCDate()) + 'T' +
f(this.getUTCHours()) + ':' +
f(this.getUTCMinutes()) + ':' +
f(this.getUTCSeconds()) + /*added - start*/ '.'+
f(this.getUTCMilliseconds()) + /*added - end*/ 'Z'
: null;
};
//pushed the below code outside current if block
// String.prototype.toJSON =
// Number.prototype.toJSON =
// Boolean.prototype.toJSON = function (key) {
// return this.valueOf();
// };
}
/*added - start*/
if (typeof String.prototype.toJSON !== 'function') {
String.prototype.toJSON = function (key) {
return ((typeof this.valueOf === 'function') ? this.valueOf(): this.toString());
};
}
if (typeof Number.prototype.toJSON !== 'function') {
Number.prototype.toJSON = function (key) {
return ((typeof this.valueOf === 'function') ? this.valueOf(): this.toString());
};
}
if (typeof Boolean.prototype.toJSON !== 'function') {
Boolean.prototype.toJSON = function (key) {
return ((typeof this.valueOf === 'function') ? this.valueOf(): this.toString());
};
}
/*added - end*/
var cx = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
escapable = /[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
gap,
indent,
meta = { // table of character substitutions
'\b': '\\b',
'\t': '\\t',
'\n': '\\n',
'\f': '\\f',
'\r': '\\r',
'"' : '\\"',
'\\': '\\\\'
},
rep;
function quote(string) {
// If the string contains no control characters, no quote characters, and no
// backslash characters, then we can safely slap some quotes around it.
// Otherwise we must also replace the offending characters with safe escape
// sequences.
escapable.lastIndex = 0;
return escapable.test(string) ? '"' + string.replace(escapable, function (a) {
var c = meta[a];
return typeof c === 'string'
? c
: '\\u' + ('0000' + a.charCodeAt(0).toString(16)).slice(-4);
}) + '"' : '"' + string + '"';
}
function str(key, holder) {
// Produce a string from holder[key].
var i, // The loop counter.
k, // The member key.
v, // The member value.
length,
mind = gap,
partial,
value = holder[key];
// If the value has a toJSON method, call it to obtain a replacement value.
if (value && typeof value === 'object' &&
typeof value.toJSON === 'function') {
value = value.toJSON(key);
}
// If we were called with a replacer function, then call the replacer to
// obtain a replacement value.
if (typeof rep === 'function') {
value = rep.call(holder, key, value);
}
// What happens next depends on the value's type.
switch (typeof value) {
case 'string':
return quote(value);
case 'number':
// JSON numbers must be finite. Encode non-finite numbers as null.
return isFinite(value) ? String(value) : 'null';
case 'boolean':
case 'null':
// If the value is a boolean or null, convert it to a string. Note:
// typeof null does not produce 'null'. The case is included here in
// the remote chance that this gets fixed someday.
return String(value);
// If the type is 'object', we might be dealing with an object or an array or
// null.
case 'object':
// Due to a specification blunder in ECMAScript, typeof null is 'object',
// so watch out for that case.
if (!value) {
return 'null';
}
// Make an array to hold the partial results of stringifying this object value.
gap += indent;
partial = [];
// Is the value an array?
if (Object.prototype.toString.apply(value) === '[object Array]') {
// The value is an array. Stringify every element. Use null as a placeholder
// for non-JSON values.
length = value.length;
for (i = 0; i < length; i += 1) {
partial[i] = str(i, value) || 'null';
}
// Join all of the elements together, separated with commas, and wrap them in
// brackets.
v = partial.length === 0
? '[]'
: gap
? '[\n' + gap + partial.join(',\n' + gap) + '\n' + mind + ']'
: '[' + partial.join(',') + ']';
gap = mind;
return v;
}
// If the replacer is an array, use it to select the members to be stringified.
if (rep && typeof rep === 'object') {
length = rep.length;
for (i = 0; i < length; i += 1) {
if (typeof rep[i] === 'string') {
k = rep[i];
v = str(k, value);
if (v) {
partial.push(quote(k) + (gap ? ': ' : ':') + v);
}
}
}
} else {
// Otherwise, iterate through all of the keys in the object.
for (k in value) {
if (Object.prototype.hasOwnProperty.call(value, k)) {
v = str(k, value);
if (v) {
partial.push(quote(k) + (gap ? ': ' : ':') + v);
}
}
}
}
// Join all of the member texts together, separated with commas,
// and wrap them in braces.
v = partial.length === 0
? '{}'
: gap
? '{\n' + gap + partial.join(',\n' + gap) + '\n' + mind + '}'
: '{' + partial.join(',') + '}';
gap = mind;
return v;
}
}
// If the JSON object does not yet have a stringify method, give it one.
if (typeof JSON.stringify !== 'function') {
JSON.stringify = function (value, replacer, space) {
// The stringify method takes a value and an optional replacer, and an optional
// space parameter, and returns a JSON text. The replacer can be a function
// that can replace values, or an array of strings that will select the keys.
// A default replacer method can be provided. Use of the space parameter can
// produce text that is more easily readable.
var i;
gap = '';
indent = '';
// If the space parameter is a number, make an indent string containing that
// many spaces.
if (typeof space === 'number') {
for (i = 0; i < space; i += 1) {
indent += ' ';
}
// If the space parameter is a string, it will be used as the indent string.
} else if (typeof space === 'string') {
indent = space;
}
// If there is a replacer, it must be a function or an array.
// Otherwise, throw an error.
rep = replacer;
if (replacer && typeof replacer !== 'function' &&
(typeof replacer !== 'object' ||
typeof replacer.length !== 'number')) {
throw new Error('JSON.stringify');
}
// Make a fake root object containing our value under the key of ''.
// Return the result of stringifying the value.
return str('', {'': value});
};
}
// If the JSON object does not yet have a parse method, give it one.
if (typeof JSON.parse !== 'function') {
JSON.parse = function (text, reviver) {
// The parse method takes a text and an optional reviver function, and returns
// a JavaScript value if the text is a valid JSON text.
var j;
function walk(holder, key) {
// The walk method is used to recursively walk the resulting structure so
// that modifications can be made.
var k, v, value = holder[key];
if (value && typeof value === 'object') {
for (k in value) {
if (Object.prototype.hasOwnProperty.call(value, k)) {
v = walk(value, k);
if (v !== undefined) {
value[k] = v;
} else {
delete value[k];
}
}
}
}
return reviver.call(holder, key, value);
}
// Parsing happens in four stages. In the first stage, we replace certain
// Unicode characters with escape sequences. JavaScript handles many characters
// incorrectly, either silently deleting them, or treating them as line endings.
text = String(text);
cx.lastIndex = 0;
if (cx.test(text)) {
text = text.replace(cx, function (a) {
return '\\u' +
('0000' + a.charCodeAt(0).toString(16)).slice(-4);
});
}
// In the second stage, we run the text against regular expressions that look
// for non-JSON patterns. We are especially concerned with '()' and 'new'
// because they can cause invocation, and '=' because it can cause mutation.
// But just to be safe, we want to reject all unexpected forms.
// We split the second stage into 4 regexp operations in order to work around
// crippling inefficiencies in IE's and Safari's regexp engines. First we
// replace the JSON backslash pairs with '#' (a non-JSON character). Second, we
// replace all simple value tokens with ']' characters. Third, we delete all
// open brackets that follow a colon or comma or that begin the text. Finally,
// we look to see that the remaining characters are only whitespace or ']' or
// ',' or ':' or '{' or '}'. If that is so, then the text is safe for eval.
if (/^[\],:{}\s]*$/
.test(text.replace(/\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g, '#')
.replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, ']')
.replace(/(?:^|:|,)(?:\s*\[)+/g, ''))) {
// In the third stage we use the eval function to compile the text into a
// JavaScript structure. The '{' operator is subject to a syntactic ambiguity
// in JavaScript: it can begin a block or an object literal. We wrap the text
// in parens to eliminate the ambiguity.
j = eval('(' + text + ')');
// In the optional fourth stage, we recursively walk the new structure, passing
// each name/value pair to a reviver function for possible transformation.
return typeof reviver === 'function'
? walk({'': j}, '')
: j;
}
// If the text is not JSON parseable, then a SyntaxError is thrown.
throw new SyntaxError('JSON.parse');
};
}
}());
Note: The above code is not my implementation. It is from the source https://github.com/douglascrockford/JSON-js I have just modified it a little to avoid any conflicts with Telerik or otherwise.

I have had exactly the same problem.
I couldn't find any other solution than to edit the json2.js file like you suggested, thanks for that.
However, I found that this would fix the issue for IE7 and still work in IE8/9 as well as firefox, but it now stopped working in Chrome ("this" for [this.valueOf === 'function'] is undefined).
Have you run into that issue, too, or did yours work in Chrome? I'm trying to figure out if this is related to my data or telerik-internal.
Thanks for your post!
Edit:
For now I have just returned null if "this" is undefined/null (in all three functions). Seems to work in all browsers and allows the Telerik grid to rebind without problems.
I don't know how correct this is in the global context of json2.js .toJSON method, though.

Related

Determining context at a position in file using ANTLR4

I'm trying to write a Language Extension for VS Code in JavaScript and I seem to be missing something.
I have a Lexer.g4 and Parser.g4 for my language and can generate a tree using them.
My issue is that the VS Code API gives me a document and a position in that document (line #, character #). From any of the examples I've looked at for ANTLR4 I can't seem to find any functions generated that take a position in the file and give back the nodes of a tree at that position.
I want to know, for example that the cursor is placed on the name of a function.
Am I supposed to be walking the entire tree and checking the position of tokens to see if they enclose the position I'm in in the editor? Or maybe I'm not using the right tool for the job? I feel like I'm probably missing something more fundamental.
Yes, you have to walk the parse tree to find the context at a given position. This is a pretty simple task and you can see it in action in my ANLTR4 exension for vscode. There are multiple functions returning something useful for a given position. For instance this one:
/**
* Returns the parse tree which covers the given position or undefined if none could be found.
*/
function parseTreeFromPosition(root: ParseTree, column: number, row: number): ParseTree | undefined {
// Does the root node actually contain the position? If not we don't need to look further.
if (root instanceof TerminalNode) {
let terminal = (root as TerminalNode);
let token = terminal.symbol;
if (token.line != row)
return undefined;
let tokenStop = token.charPositionInLine + (token.stopIndex - token.startIndex + 1);
if (token.charPositionInLine <= column && tokenStop >= column) {
return terminal;
}
return undefined;
} else {
let context = (root as ParserRuleContext);
if (!context.start || !context.stop) { // Invalid tree?
return undefined;
}
if (context.start.line > row || (context.start.line == row && column < context.start.charPositionInLine)) {
return undefined;
}
let tokenStop = context.stop.charPositionInLine + (context.stop.stopIndex - context.stop.startIndex + 1);
if (context.stop.line < row || (context.stop.line == row && tokenStop < column)) {
return undefined;
}
if (context.children) {
for (let child of context.children) {
let result = parseTreeFromPosition(child, column, row);
if (result) {
return result;
}
}
}
return context;
}
}

readString is throwing TypeError: malformed UTF-8

This function returns a ctypes.unsigned_char.array() and I do read string on it. It is getting the titles of windows. The problem is sometimes it throws TypeError.
try {
console.error('straight readString on XWindowGetProperty data:', rez_GP.data.readString());
} catch (ex) {
console.error('ex on straight readString:', ex);
}
Please notice the rez_GP.data.readString()
For example this instance: TypeError: malformed UTF-8 character sequence at offset 48. In this situation the window title is Editing js-macosx/bootstrap.js at base-template · Noitidart/js-macosx - Mozilla Firefox The 48th offset is that dot chracter you see, it's chracter code is 183. How to do readString() on this buffer without getting this error?
Thanks
readString expects a utf-8 encoded string. This is true for strings returned by _NET_WM_NAME, but not for WM_NAME.
I found a way to read the string propertly even ifs not utf-8, but im not sure if its he best way or the recommended way. This works though, i have to cast it to unsigned_char (must be this, so not char or jschar) then do fromCharCode:
function readAsChar8ThenAsChar16(stringPtr, known_len, jschar) {
// when reading as jschar it assumes max length of 500
// stringPtr is either char or jschar, if you know its jschar for sure, pass 2nd arg as true
// if known_len is passed, then assumption is not made, at the known_len position in array we will see a null char
// i tried getting known_len from stringPtr but its not possible, it has be known, i tried this:
//"stringPtr.contents.toString()" "95"
//"stringPtr.toString()" "ctypes.unsigned_char.ptr(ctypes.UInt64("0x7f73d5c87650"))"
// so as we see neither of these is 77, this is for the example of "_scratchpad/EnTeHandle.js at master · Noitidart/_scratchpad - Mozilla Firefox"
// tries to do read string on stringPtr, if it fails then it falls to read as jschar
var readJSCharString = function() {
var assumption_max_len = known_len ? known_len : 500;
var ptrAsArr = ctypes.cast(stringPtr, ctypes.unsigned_char.array(assumption_max_len).ptr).contents; // MUST cast to unsigned char (not ctypes.jschar, or ctypes.char) as otherwise i dont get foreign characters, as they are got as negative values, and i should read till i find a 0 which is null terminator which will have unsigned_char code of 0 // can test this by reading a string like this: "_scratchpad/EnTeHandle.js at master · Noitidart/_scratchpad - Mozilla Firefox" at js array position 36 (so 37 if count from 1), we see 183, and at 77 we see char code of 0 IF casted to unsigned_char, if casted to char we see -73 at pos 36 but pos 77 still 0, if casted to jschar we see chineese characters in all spots expect spaces even null terminator is a chineese character
console.info('ptrAsArr.length:', ptrAsArr.length);
//console.log('debug-msg :: dataCasted:', dataCasted, uneval(dataCasted), dataCasted.toString());
var charCode = [];
var fromCharCode = []
for (var i=0; i<ptrAsArr.length; i++) { //if known_len is correct, then will not hit null terminator so like in example of "_scratchpad/EnTeHandle.js at master · Noitidart/_scratchpad - Mozilla Firefox" if you pass length of 77, then null term will not get hit by this loop as null term is at pos 77 and we go till `< known_len`
var thisUnsignedCharCode = ptrAsArr.addressOfElement(i).contents;
if (thisUnsignedCharCode == 0) {
// reached null terminator, break
console.log('reached null terminator, at pos: ', i);
break;
}
charCode.push(thisUnsignedCharCode);
fromCharCode.push(String.fromCharCode(thisUnsignedCharCode));
}
console.info('charCode:', charCode);
console.info('fromCharCode:', fromCharCode);
var char16_val = fromCharCode.join('');
console.info('char16_val:', char16_val);
return char16_val;
}
if (!jschar) {
try {
var char8_val = stringPtr.readString();
console.info('stringPtr.readString():', char8_val);
return char8_val;
} catch (ex if ex.message.indexOf('malformed UTF-8 character sequence at offset ') == 0) {
console.warn('ex of offset utf8 read error when trying to do readString so using alternative method, ex:', ex);
return readJSCharString();
}
} else {
return readJSCharString();
}
}

What is the default return value of a Dart function?

The function below works even though I intentionally deleted 'return' command:
main() {
add(i) => i + 2; //I intentionally deleted 'return'
print(add(3)); //5
}
But, the function below doesn't work after I intentionally deleted the 'return' command.
main() {
makeAdder(num addBy) {
return (num i) {
addBy + i; //I intentionally deleted 'return'
};
}
var add2 = makeAdder(2);
print(add2(3) ); //expected 5, but null.
}
Edited to clarify my question.
The last sentence in the latter function above, add2(3) doesn't return a value(I expect 5) but just null returns.
My question is why 'addBy + i' of the latter function doesn't return contrary to the fact that 'add(i) => i + 2' of the first function returns 'i + 2'.
Edited again.
The answer is in the fact of '=>' being {return }, not just {}.
main() {
makeAdder(num addBy) => (num i) { return addBy + i; };
var add2 = makeAdder(2);
print(add2(3) ); // 5
}
Even the code below works as '=>' has 'return' command in it.
main() {
makeAdder(num addBy) => (num i) => addBy + i; ;
var add2 = makeAdder(2);
print(add2(3) ); //5
}
In Dart each function without an explicit return someValue; returns null;
The null object does not have a method 'call'.
makeAdder (add2) without return returns null and null(3) leads to the exception.
I would like to quote two important note here. It might help others:
Though Dart is Optionally typed ( meaning, specifying the return type of a function such as int or void is optional ), it always recommended to specify type wherever possible. In your code, as a sign of good programming practice, do mention the return type.
If your function does not return a value then specify void. If you omit the return type then it will by default return null.
All functions return a value. If no return value is specified, the statement return null; is implicitly appended to the function body.

SQL CLR User Defined Function (C#) adds null character (\0) in between every existing character in String being returned

This one has kept me stumped for a couple of days now.
It's my first dabble with CLR & UDF ...
I have created a user defined function that takes a multiline String as input, scans it and replaces a certain line in the string with an alternative if found. If it is not found, it simply appends the desired line at the end. (See code)
The problem, it seems, comes when the final String (or Stringbuilder) is converted to an SqlString or SqlChars. The converted, returned String always contains the Nul character as every second character (viewing via console output, they are displayed as spaces).
I'm probably missing something fundamental on UDF and/or CLR.
Please Help!!
Code (I leave in the commented Stringbuilder which was my initial attempt... changed to normal String in a desperate attempt to find the issue):
[Microsoft.SqlServer.Server.SqlFunction]
[return: SqlFacet(MaxSize = -1, IsFixedLength = false)]
//public static SqlString udf_OmaChangeJob(String omaIn, SqlInt32 jobNumber) {
public static SqlChars udf_OmaChangeJob(String omaIn, SqlInt32 jobNumber) {
if (omaIn == null || omaIn.ToString().Length <= 0) return new SqlChars("");
String[] lines = Regex.Split(omaIn.ToString(), "\r\n");
Regex JobTag = new Regex(#"^JOB=.+$");
//StringBuilder buffer = new StringBuilder();
String buffer = String.Empty;
bool matched = false;
foreach (var line in lines) {
if (!JobTag.IsMatch(line))
//buffer.AppendLine(line);
buffer += line + "\r\n";
else {
//buffer.AppendLine("JOB=" + jobNumber);
buffer += ("JOB=" + jobNumber + "\r\n");
matched = true;
}
}
if (!matched) //buffer.AppendLine("JOB=" + jobNumber);
buffer += ("JOB=" + jobNumber) + "\r\n";
//return new SqlString(buffer.ToString().Replace("\0",String.Empty)) + "blablabla";
// buffer = buffer.Replace("\0", "|");
return new SqlChars(buffer + "\r\nTheEnd");
}
I know in my experiences, the omaIn parameter should be of type SqlString and when you go to collect its value/process it, set a local variable:
string omaString = omaIn != SqlString.Null ? omaIn.Value : string.empty;
Then when you return on any code path, to rewrap the string in C#, you'd need to set
return omaString == string.empty ? new SqlString.Null : new SqlString(omaString);
I have had some fun wrestling matches learning the intricate hand-off between local and outbound types, especially with CLR TVFs.
Hope that can help!

How to match the start and end of a block

I want to define a special code block, which may starts by any combination of characters of {[<#, and the end will be }]>#.
Some example:
{
block-content
}
{##
block-content
##}
#[[<{###
block-content
###}>]]#
Is it possible with petitparser-dart?
Yes, back-references are possible, but it is not that straight-forward.
First we need a function that can reverse our delimiter. I came up with the following:
String reverseDelimiter(String token) {
return token.split('').reversed.map((char) {
if (char == '[') return ']';
if (char == '{') return '}';
if (char == '<') return '>';
return char;
}).join();
}
Then we have to declare the stopDelimiter parser. It is undefined at this point, but will be replaced with the real parser as soon as we know it.
var stopDelimiter = undefined();
In the action of the startDelimiter we replace the stopDelimiter with a dynamically created parser as follows:
var startDelimiter = pattern('#<{[').plus().flatten().map((String start) {
stopDelimiter.set(string(reverseDelimiter(start)).flatten());
return start;
});
The rest is trivial, but depends on your exact requirements:
var blockContents = any().starLazy(stopDelimiter).flatten();
var parser = startDelimiter & blockContents & stopDelimiter;
The code above defines the blockContents parser so that it reads through anything until the matching stopDelimiter is encountered. The provided examples pass:
print(parser.parse('{ block-content }'));
// Success[1:18]: [{, block-content , }]
print(parser.parse('{## block-content ##}'));
// Success[1:22]: [{##, block-content , ##}]
print(parser.parse('#[[<{### block-content ###}>]]#'));
// Success[1:32]: [#[[<{###, block-content , ###}>]]#]
The above code doesn't work if you want to nest the parser. If necessary, that problem can be avoided by remembering the previous stopDelimiter and restoring it.

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