How to Send Data Between Scripts in AutoHotkey v2 - OnMessage

Introduction

This tutorial will guide you through the process of sending data between scripts in AutoHotkey v2 using the OnMessage function. This capability allows for efficient communication between different scripts, enhancing your automation workflows. Whether you're looking to share variables or trigger actions across scripts, understanding OnMessage is essential.

Step 1: Setting Up Your Scripts

Before you can send data, you need to create the scripts that will communicate with each other.

1. Create the First Script (Sender)

   • Open your preferred text editor.
   • Write a simple script that will send data. Here’s an example:

     ; Sender.ahk
     OnMessage(0x1234, "ReceiveData")
     
     SendData() {
         PostMessage(0x1234, "Hello from Sender", 0, "ahk_id " . WinExist("Receiver"))
     }
     
     ReceiveData(wParam, lParam, msg, hwnd) {
         MsgBox "Data received: " . lParam
     }
     
     ; Call SendData to send the message
     SendData()
     

2. Create the Second Script (Receiver)

   • In another text file, write the script that will receive the data:

     ; Receiver.ahk
     OnMessage(0x1234, "HandleMessage")
     
     HandleMessage(wParam, lParam, msg, hwnd) {
         MsgBox "Received message: " . lParam
     }
     

Step 2: Running the Scripts

To see the communication in action, you need to run both scripts simultaneously.

1. Run the Receiver Script

   • Start the Receiver script first. This script will wait for incoming messages.

2. Run the Sender Script

   • Now, run the Sender script. It will send a message to the Receiver script.

Step 3: Understanding the Code

Familiarize yourself with how the code works for better implementation in your own projects.

• OnMessage: This function allows scripts to register a message handler for a specific message ID.
• PostMessage: This function sends a message to a specified window. You can use it to send data to the Receiver.
• MsgBox: Used to display a message box with the received data.

Step 4: Practical Applications

Consider how you can use this functionality in real-world scenarios:

• Inter-Script Communication: Share variables or trigger functions across scripts.
• Modular Automation: Create separate scripts for different tasks that can communicate, allowing for more organized and efficient automation.

Conclusion

You have now learned how to send data between scripts in AutoHotkey v2 using the OnMessage function. This functionality opens up a range of possibilities for automating tasks more effectively. As a next step, experiment with sending different types of data or implementing more complex interactions between your scripts. Happy scripting!