Input action maps in Unity - Step-by-Step Execution

Concept Flow - Input action maps

Define Input Actions

↓

Create Input Action Map

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Add Actions to Map

↓

Enable Action Map

↓

Listen for Input Events

↓

Respond to Input

↓

Disable Action Map when done

Input action maps group input actions. You define actions, add them to a map, enable the map, then listen and respond to inputs.

Execution Sample

Unity

var playerActions = new InputActionMap("Player");
var jump = playerActions.AddAction("Jump", binding: "<Keyboard>/space");
jump.performed += ctx => Debug.Log("Jump pressed");
playerActions.Enable();

This code creates an input action map named 'Player', adds a 'Jump' action bound to the spacebar, listens for the jump action, and enables the map.

Execution Table

Step	Action	InputActionMap State	Event Subscription	Output
1	Create InputActionMap 'Player'	Empty map created	No subscriptions	No output
2	Add 'Jump' action with spacebar binding	Map has 1 action: 'Jump'	No subscriptions	No output
3	Subscribe to 'Jump.performed' event	Map unchanged	Jump action subscribed to event	No output
4	Enable InputActionMap	Map enabled	Subscriptions active	No output
5	Press spacebar	Map enabled	Jump.performed event triggered	Console logs 'Jump pressed'
6	Disable InputActionMap	Map disabled	Subscriptions inactive	No output

💡 InputActionMap disabled, no further input events processed

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	After Step 5	After Step 6
playerActions	null	Empty InputActionMap	Contains 'Jump' action	Same	Enabled	Enabled	Disabled
jump	null	null	InputAction bound to spacebar	Subscribed to performed event	Same	Same	Same

Key Moments - 3 Insights

Why do we need to enable the InputActionMap before it detects input?

The InputActionMap only listens for input when enabled, as shown in step 4 and 5 of the execution_table. Without enabling, input events won't trigger.

What happens if we add an action but don't subscribe to its events?

Adding an action alone doesn't produce output. You must subscribe to events like 'performed' to respond, as shown in step 3 and 5.

Why disable the InputActionMap after use?

Disabling stops listening to inputs and frees resources, preventing unwanted input handling, as shown in step 6.

Visual Quiz - 3 Questions

Look at the execution_table, what is the state of 'playerActions' after step 4?

A Enabled

B Empty

C Disabled

D Null

💡 Hint

Check the 'InputActionMap State' column at step 4 in the execution_table

At which step does the 'Jump.performed' event subscription happen?

A Step 2

B Step 3

C Step 4

D Step 5

💡 Hint

Look at the 'Event Subscription' column in the execution_table

If we never call 'playerActions.Enable()', what happens when pressing spacebar?

A Console logs 'Jump pressed'

B Error thrown

C No output, input ignored

D InputActionMap disables automatically

💡 Hint

Refer to step 4 and 5 in the execution_table about enabling the map

Concept Snapshot

Input Action Maps group input actions.
Define actions and add to a map.
Subscribe to action events (e.g., performed).
Enable the map to listen for inputs.
Disable when done to stop listening.

Full Transcript

Input action maps in Unity help organize input controls. First, you create an InputActionMap, then add actions like 'Jump' with specific bindings such as the spacebar. You subscribe to events like 'performed' to respond when the input happens. Enabling the map starts listening for inputs, and disabling stops it. This process ensures your game reacts only when you want it to, keeping input handling clean and efficient.