// SPDX-License-Identifier: MIT
// Copyright (c) 2026 Incoprea
// Distinguish a missing field from explicit null
// Not compiled or tested in-world
// Setup: Edit DOCUMENT and the example settings, then touch as owner. Requires simulator support for LSL JSON functions.
// Stop / restore: Remove or disable. JSON changes occur only in a local preview string.
// Notes: These states can have different configuration meanings. This example reports the distinction without choosing a fallback automatically.
// License: see LICENSE in this distribution.
// Original Incoprea example. MIT.
string DOCUMENT="{\"label\":\"\",\"subtitle\":null}";
string FIELD="label";
default
{
    touch_start(integer touches)
    {
        if(llDetectedKey(0)!=llGetOwner())return;
        string kind=llJsonValueType(DOCUMENT,[FIELD]);
        if(kind==JSON_INVALID)llOwnerSay("Field absent.");
        else if(kind==JSON_NULL)llOwnerSay("Field explicitly null.");
        else if(kind==JSON_STRING && llJsonGetValue(DOCUMENT,[FIELD])=="")llOwnerSay("Field is an intentional empty string.");
        else llOwnerSay("Field exists with a non-null value.");
    }
    changed(integer flags)
    {
        if(flags & CHANGED_OWNER)llResetScript();
    }
}