Macro Handler

Macro Handler

Android Automation Platform

Object MethodData and Files

Str.charAt(source, index)

Returns the character at a 0-based position, or an empty string when out of range.

Documented for app version 1.0.51Updated:

Detailed Explanation

This section explains when to use the API, how to call it, and which structures it works best with in production flow.

How To Call It

Str is a global table: call its functions with a dot (Str.<method>(...)), not a colon.

When To Use It

In data flow, chaining JSON, Regex, Str, Map, and File steps to normalize intermediate values reduces error risk.

Parameters and Return

Required: source, index. Returns a string.

Best Combined With

When combined with Str, JSON, Regex, Array, Map, and File, data transformation becomes much more readable in script flow.

Example Usage

The snippet below is a starter pattern that can be applied directly in runtime flow.

lua
Try in Editor →
local result = Str.charAt("Macro Handler", 1)

Copyable Progressive Examples

From foundation to combined usage, each level is provided as a separate code block so you can copy the level you need and adapt it directly.

Foundation

Shows the shortest direct way to call the API.

Foundation
lua
Try in Editor →
local result = Str.charAt("Macro Handler", 1)

Simple

Wraps the base call with minimal flow control.

Simple
lua
Try in Editor →
local stepOk = true
local result = Str.charAt("Macro Handler", 1)
if stepOk then
  wait(200)
end

Practical Flow

A practical pattern for real macros with pcall, logging, and guards.

Practical Flow
lua
Try in Editor →
local ok, err = pcall(function()
  local result = Str.charAt("Macro Handler", 1)
end)

if not ok then
  print("API step failed: Str.charAt: " .. tostring(err))
  requestStop()
end

Detailed

This level packages the API into a reusable helper with error reporting.

Detailed
lua
Try in Editor →
-- In data flow, chaining JSON, Regex, Str, Map, and File steps to normalize intermediate values reduces error risk.
local function run_charat_step()
  local result = Str.charAt("Macro Handler", 1)
end

local ok, err = pcall(run_charat_step)
if not ok then
  toast("Step failed")
  print(err)
end

Combined

Combines the API with related structures to form a more realistic workflow.

Combined
lua
Try in Editor →
local result = Str.charAt("Macro Handler", 1)
local raw = File.read("macro.log")
local normalized = Str.trim(raw)
print(normalized)