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Second Life Creation

llList2Json

string llList2Json(string JsonType, list Values)

Converts either a strided list of key:value pairs to a JSON_OBJECT, or a list of values to a JSON_ARRAY.

Parameters
JsonType (string)
Type is JSON_ARRAY or JSON_OBJECT.
Values (list)
List of values to convert.
Technical Details
  • Return Type: string
  • Energy: 10

Basic Usage

Section titled “Basic Usage”
default
{
    state_entry()
    {
        list items;
        string json;


        items = ["89556747-24cb-43ed-920b-47caed15465f"];
        json = llList2Json(JSON_ARRAY, items);
        // ["89556747-24cb-43ed-920b-47caed15465f"]


        items = ["pi", 3.14, "set", "[1,2,3]", "status", "ok"];
        json = llList2Json(JSON_OBJECT, items);
        // {"pi":3.140000,"set":[1,2,3],"status":"ok"}


        items = [0, 3.14, "[1,2,3]", "{}"];
        json = llList2Json(JSON_ARRAY, items);
        // [0,3.140000,[1,2,3],{}]
    }
}

Convert CSV to JSON

Section titled “Convert CSV to JSON”
string CSV2Json(string csv)
{
    list li = llCSV2List(csv);
    return llList2Json(JSON_ARRAY, li);
}
// This function converts a comma separated values string to a Json array string.
// CSV strings are often used for link-messages, notecards and they are easier to type as input commands.
// A Json-Array can store multiple of those as a nested list within the same Json-string via JSON_APPEND.

Usage Patterns

Section titled “Usage Patterns”

  • You could store multiple lists that set different particle effects in the same string. Use llList2Json() to write the string and llJson2List() to read the particle system defining lists from it. The loss in float-accuracy (JSON has limited float-to-string conversion) does not matter as much for particle effects.

  • You could store multiple lists that set different llSetPrimitiveParamsFast() values for different situations (like different animation key frames) in the same JSON string.

Type Conversion

Section titled “Type Conversion”

The function infers JSON types from LSL data types:

  • Integer and float types are encoded as JSON_NUMBER
  • "true" and "false" are encoded as JSON_TRUE and JSON_FALSE, respectively
  • "null" is encoded as JSON_NULL
  • Properly-formatted JSON strings in the input are kept as-is (will either be JSON_STRING, JSON_OBJECT, or JSON_ARRAY)
  • All other strings are encoded as JSON_STRING. Strings are trimmed of whitespace at the beginning and end, as if passed through llStringTrim
  • Note: strings containing valid JSON numbers are converted to JSON strings, not left as JSON numbers. This differs from the treatment that llJsonSetValue gives to strings containing JSON numbers, which leaves them as numbers.

Caveats

Section titled “Caveats”
  • If type is JSON_OBJECT, the list must be a strided list of key, value pairs and a string representing a JSON object will be returned.
  • If type is JSON_ARRAY, then a string representing a JSON array will be returned.
  • If type is any other string, JSON_INVALID will be returned.
  • String values are interpreted as JSON, not LSL strings. Quotation marks, if required, must be added explicitly. For example:
    • llJson2List(llList2Json(JSON_ARRAY, ["bacon", "true", "false", "null"])) returns the LSL list ["bacon", JSON_TRUE, JSON_FALSE, JSON_NULL]
    • llJson2List(llList2Json(JSON_ARRAY, ["\"bacon\"", "\"true\"", "\"false\"", "\"null\""])) returns the LSL list ["bacon", "true", "false", "null"]

See Also

Section titled “See Also”