Lua Requires Chilkat v11.4.0+

Call a JavaScript Function Returning an Array

See more JavaScript Examples

Demonstrates how to call a JavaScript function that returns an array. Lua

local chilkat = require("chilkat")

-- ----------------------------------------------------------------------------------
-- The Javascript functions called in this example are shown at the bottom of this page.
-- -----------------------------------------------------------------------------------

local sbScript = chilkat.StringBuilder.new()
local success = sbScript:load_file("js_function_returning_array.js", "utf-8")
if not success then
    print(sbScript.last_error_text)
    return
end

local js = chilkat.Js.new()

local result = chilkat.JsonObject.new()
result.emit_compact = false

-- Call Eval to add the function to the context's global object
success = js:eval(sbScript, result)
if not success then
    -- Examine the result for an exception.
    print(result:emit())

    -- Also examine the LastErrorText.
    print(js.last_error_text)
    return
end

-- ------------------------------------------------------------------------------
-- Call each function

local funcCall = chilkat.JsonObject.new()

-- Create JSON specifying the function name and arguments
-- The function has no arguments, so we only specify the name.

funcCall:update_string("name", "getDays")

success = js:call_function(funcCall, result)
if not success then
    -- Examine the result for an exception.
    print(result:emit())

    -- Also examine the LastErrorText.
    print(js.last_error_text)
    return
end

print(result:emit())

-- Output:
-- {
--   "type": "array",
--   "value": [
--     "Monday",
--     "Tuesday",
--     "Wednesday",
--     "Thursday",
--     "Friday"
--   ]
-- }

-- Access each array value..
local count = result:size_of_array("value")
local i = 0
while i < count do
    result.i = i
    print(result:string_of("value[i]"))
    i = i + 1
end

-- ------------------------------------------------------------------------------
-- Call the getRange(start,end) function

funcCall:clear()
funcCall:update_string("name", "getRange")
funcCall:update_int("args[0]", 14)
funcCall:update_int("args[1]", 21)
success = js:call_function(funcCall, result)
print(result:emit())

-- Output:
-- {
--   "type": "array",
--   "value": [
--     14,
--     15,
--     16,
--     17,
--     18,
--     19,
--     20,
--     21
--   ]
-- }

count = result:size_of_array("value")
i = 0
while i < count do
    result.i = i
    print(result:int_of("value[i]"))
    i = i + 1
end

-- ------------------------------------------------------------------------------
-- Call the getEmployees() function

funcCall:clear()
funcCall:update_string("name", "getEmployees")
success = js:call_function(funcCall, result)
print(result:emit())

-- Output:
-- {
--   "type": "array",
--   "value": [
--     {
--       "id": 101,
--       "name": "Alice",
--       "role": "Dev"
--     },
--     {
--       "id": 102,
--       "name": "Bob",
--       "role": "Manager"
--     }
--   ]
-- }

count = result:size_of_array("value")
i = 0
while i < count do
    result.i = i
    print("name: " .. result:string_of("value[i].name"))
    print("role: " .. result:string_of("value[i].role"))
    print("id: " .. result:int_of("value[i].id"))
    print("")
    i = i + 1
end

JavaScript

function getDays() {
    return ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday"];
}

function getRange(start, end) {
    var arr = [];
    for (var i = start; i <= end; i++) {
        arr.push(i);
    }
    return arr;
}
// Usage: getRange(1, 5) -> [1, 2, 3, 4, 5]

function getEmployees() {
    return [
        { id: 101, name: "Alice", role: "Dev" },
        { id: 102, name: "Bob", role: "Manager" }
    ];
}