View source for User:LepreKhaun Resident/Json Get Value Safe

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<source lang = "lsl2">//////////////////////////////
// function string uJsonGetValueSafe (string jsonText, list specifiers)
// Same specification as llJsonGetValue() except returns all Strings
// enclosed within double quotes and exactly as they appear within jsonText
//
// Version 1.0 by LepreKhaun 9/9/20
// May be freely used, modified and distributed with this header intact.
// Compiled Size = 4,608 bytes
///////////////////////////////

string uJsonGetValueSafe (string jsonText, list specifiers)
{
	string rString = "";

	// no need for further processing if not String
	if (llJsonValueType(jsonText, specifiers) != JSON_STRING) 
	{
		rString = llJsonGetValue(jsonText, specifiers);

	// specifiers may be an empty list and we're dealing with simply a JSON_STRING
	}
	else if (llGetListLength(specifiers) == 0) 
	{
		rString = jsonText;

	}
	else
	{
		// used for assembling the return string
		string char = "";
		string prevChar = "";

		// boolean flag
		integer inQuote = FALSE;

		// used to step through Array/Object Values
		// NOTE: Takes valid, compliant Json text for granted
		integer inArrayObject = 0;

		integer iter = 0;

		// we need to extract the parent of the String Value
		list valueSpecifier = llList2List(specifiers, -1, -1);

		// shorten specifiers to point to parent of the Value
		specifiers = llDeleteSubList(specifiers, -1, -1);

		// extract the parent
		jsonText = llJsonGetValue(jsonText, specifiers);

		if (llGetListEntryType(valueSpecifier, 0) == TYPE_INTEGER)
		{
			// we're dealing with an array
			integer sPos = llList2Integer(valueSpecifier, 0);

			// used to step through array Values
			integer count = 0;

			// find start of our String Value within array
			while (count < sPos)
			{
				char = llGetSubString(jsonText, ++iter, iter);
				if (char == "\"" && prevChar != "\\") //"//
				{
					inQuote = !inQuote;
				}
				else if ((char == "[" || char == "{") && !inQuote)
				{
					++inArrayObject;
				}
				else if ((char == "]" || char == "}") && !inQuote)
				{
					--inArrayObject;
				}
				else if (char == "," && !inQuote && !inArrayObject)
				{
					++count;
				}
				prevChar = char;
			}
			// eat possible white space
			while ((rString = llGetSubString(jsonText, ++iter, iter)) != "\""){};
			// Now assemble return string
			inQuote = TRUE;
			prevChar = "";
			while (inQuote)
			{
				char = llGetSubString(jsonText, ++iter, iter);
				rString = rString + char;
				if (char == "\"" && prevChar != "\\") //"//
				{
					inQuote = FALSE;
				}
				prevChar = char;
			}

		}
		else
		{
			// otherwise, we must be dealing with an object

			// make the key for comparison
			string sKey = llList2String(valueSpecifier, 0);

			// and encode it as a JSON_STRING if it's not
			if (llGetSubString(sKey, 0, 0) != "\"")
			{
				sKey = "\"" + sKey + "\"";
			}
			
			// used for a possible "Key" used in comparison
			string pKey;

			integer jtLength = llStringLength(jsonText) - 1;

			while (iter < jtLength)
			{
				// go to start of a possible "Key"
				while (llGetSubString(jsonText, ++iter, iter) != "\"")
				{
				};

				// form pKey
				pKey = "\"";
				inQuote = TRUE;
				while (inQuote)
				{
					char = llGetSubString(jsonText, ++iter, iter);
					pKey = pKey + char;
					if (char == "\"" && prevChar != "\\") //"//
					{
						inQuote = FALSE;
					}
					prevChar = char;
				}

				// move to start of Value, eating possible white space
				while (llGetSubString(jsonText, ++iter, iter) != ":")
				{
				};

				char = llEscapeURL(llGetSubString(jsonText, ++iter, iter));

				while (char == "%20" || char == "%09" || char == "%0a" || char == "%0d")
				{
					char = llEscapeURL(llGetSubString(jsonText, ++iter, iter));
				}

				char = llUnescapeURL(char);

				// check "Key" for match with sKey AND start of a String Value
				if (pKey == sKey && char == "\"")
				{
					// assemble Value
					prevChar = "";
					inQuote = TRUE;
					rString = "\"";

					while (inQuote)
					{
						char = llGetSubString(jsonText, ++iter, iter);
						rString = rString + char;
						if (char == "\"" && prevChar != "\\") //"//
						{
							inQuote = FALSE;
						}
						prevChar = char;
					}
					
					// move to ',' or '}' (next "Key"Value pair or end of object)
					while(!(llGetSubString(jsonText, ++iter, iter) == "," || llGetSubString(jsonText, iter, iter) == "}")){};
				}
				else
				{
					// eat Value to next Key or end of object
					integer inValue = TRUE;
					prevChar = "";
					inArrayObject = 0;
					inQuote = FALSE;

					while (inValue)
					{
						char = llGetSubString(jsonText, iter, iter++);
						if (char == "\"" && prevChar != "\\") //"//
						{
							inQuote = !inQuote; 
						}
						else if ((char == "," || char == "}") && !inQuote && !inArrayObject)
						{
							inValue = FALSE;
							--iter;
						}
						else if ((char == "[" || char == "{") && !inQuote)
						{
							++inArrayObject;
						}
						else if ((char == "]" || char == "}") && !inQuote)
						{
							--inArrayObject;
						}
						prevChar = char;
					}
				}
			}
		}
	}
	return rString;
}

// example usage and comparison
default {
	touch_end (integer i){
		string jText = "{\"B\":\"Z\",\"C\":[1,\"a\\r\\t\\f\",3],\"A\":\"H\\n\\u23AF\"}";
		llOwnerSay(jText); // => '{"B":"Z","C":[1,"a\r\t\f",3],"A":"H\n\u23AF"}'
		
		llOwnerSay(llJsonGetValue(jText, ["A"])); // => 'H' then Unicode character for New Line then 'u23AF'
		llOwnerSay(uJsonGetValueSafe(jText, ["A"])); // => "H\n\u23AF"

		llOwnerSay(llJsonGetValue(jText, ["B"])); // => 'Z'
		llOwnerSay(uJsonGetValueSafe(jText, ["B"])); // => "Z"

		llOwnerSay(llJsonGetValue(jText, ["C"])); // => '[1,"a\r\t\f",3]'
		llOwnerSay(uJsonGetValueSafe(jText, ["C"])); // => '[1,"a\r\t\f",3]'
		
		llOwnerSay(llJsonGetValue(jText, ["C", 0])); // => '1'
		llOwnerSay(uJsonGetValueSafe(jText, ["C", 0])); // => '1'

		llOwnerSay(llJsonGetValue(jText, ["C", 1])); // => 'a' then Unicode characters for the escaped sequences
		llOwnerSay(uJsonGetValueSafe(jText, ["C", 1])); // => "a\r\t\f"

		llOwnerSay(llJsonGetValue(jText, ["C", 2])); // => '3'
		llOwnerSay(uJsonGetValueSafe(jText, ["C", 2])); // => '3'
	}
}</source>

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