Lua Requires Chilkat v11.4.0+

JavaScript console using Callbacks

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Demonstrates console output using Chilkat JavaScript with callbacks. Lua

local chilkat = require("chilkat")

-- This example demonstrates using the built-in console object.
-- The Javascript run in this example is shown below.

-- Load the JavaScript from a file.
local sbScript = chilkat.StringBuilder.new()
local success = sbScript:load_file("qa_data/js_tests/test_console.js", "utf-8")
if not success then
    print(sbScript.last_error_text)
    return
end

local js = chilkat.Js.new()
js:set_event_handler({
    progress_info = function(name, value)
        print(name .. ": " .. value)
    end,
})
local result = chilkat.JsonObject.new()

-- Run the JavaScript
-- Results (not console output) go to result.
-- Note: Eval returns the completion value of the script. This is generally the value of the last evaluated expression.
-- In this case, the last evaluated expression is console.log which does not calculate a value. Therefore, it returns undefined.
success = js:eval(sbScript, result)
if not success then
    print(sbScript.last_error_text)
    return
end

-- We can look at the result, which is "undefined", which is normal and expected.
print(result:emit())
-- The result JSON is: {"type":"undefined","value":"undefined"}

-- The console output is received using ProgressInfo callbacks.
-- The output is:

-- log: Hello World, 248, 12.05
--
-- error: foo:bar baz
--
-- warn: 1 2 3
--
-- log: %% %s
--
-- log: myApp: {
--   "appName": "Example",
--   "version": 1,
--   "isDebug": true,
--   "supportedTypes": [
--     "string",
--     "number",
--     "object"
--   ],
--   "settings": {
--     "maxWidgets": 1024,
--     "allowIO": true
--   }
-- }
--
-- log: App: myApp (Version 1)
--
-- {"type":"undefined","value":"undefined"}

JavaScript

// Chilkat Js console emits CRLF line endings on Windows, and LF line endings on non-Windows.

console.log("Hello %s, %d, %f", "World", 248, 12.05);
// Output: Hello World, 248, 12.05

// If there are more arguments than the number of specifiers, the extra arguments are output, separated by spaces:
console.error('%s:%s', 'foo', 'bar', 'baz');
// Output: foo:bar baz

// If the first argument does not contain a valid format specifier, outputs a string that is the concatenation of all arguments separated by spaces:
console.warn(1,2,3);
// Output: 1 2 3

//If only one argument is passed, it is returned as it is without any formatting:
console.log("%% %s");
// Output: %% %s

const myApp = {
    appName: "Example",
    version: 1.0,
    isDebug: true,
    supportedTypes: ["string", "number", "object"],
    settings: {
       "maxWidgets": 1024,
        allowIO: true
    }
};

// %O: Emits the same as JSON.stringify(myConfig, null, 2)
console.log("myApp: %O", myApp);
// Output:
// myApp: {
//   "appName": "Example",
//   "version": 1,
//   "isDebug": true,
//   "supportedTypes": [
//     "string",
//     "number",
//     "object"
//   ],
//   "settings": {
//     "maxWidgets": 1024,
//     "allowIO": true
//   }
// }

console.log("App: %s (Version %d)", myApp.appName, myApp.version);
// Output: App: Example (Version 1)