Google Sheets Loader for GameMaker

A simple, powerful & type-smart CSV loader
that fetches data directly from published Google Sheets

🚀 GameMaker • 📊 Google Sheets • 🔧 Type-Safe • ⚡ Async

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Table of Contents

• Features
• Why use this?
• Installation
• Quick Start Example
• Basic Usage
• Executable Functions
• Debug & Utility Functions
• Supported Data Types
• Troubleshooting
• Tips & Best Practices

Features

• Load data directly from published Google Sheets using only Sheet ID
• Smart automatic type detection & conversion
• Supports executable function callbacks in cells
• Async / non-blocking loading
• Can load specific tabs (using gid)
• Built-in debug & inspection tools

Why use this?

Old classic way (hard-coded):

items[0] = { name: "Banana",  color: "yellow", price: 12 };
items[1] = { name: "Apple",   color: "red",    price: 10 };
// ... painful to edit & maintain

Modern way with Google Sheets Loader:

obj_GMGSL.load_sheet("YOUR_SHEET_ID", "", function(data) {
    global.items = data;     // ← done!
});

Perfect for: items, enemies, levels, dialogue, localization, balancing, live events, non-programmer content updates...

Installation

1. Download GMGSL.yymps from Releases
2. GameMaker → Tools → Import Local Package
3. Select file → choose obj_GMGSL → Import
4. Drag obj_GMGSL into any room (persistent object)

Important – Google Sheet publishing:
File → Share → Publish to web → Web page (NOT CSV!)
Copy the Sheet ID from the published link

Quick Start Example

name	price	description
Sword	100	A sharp blade
Shield	50	Protects from harm
Potion	25	Restores health

obj_GMGSL.load_sheet("YOUR_SHEET_ID", "", function(data) {
    _gmgsl_debug_sheet_data_compact(data); // quick visual check
    
    for (var i = 0; i < array_length(data); i++) {
        var item = data[i];
        show_debug_message(item.name + " costs " + string(item.price) + " gold");
    }
});

Basic Usage

// Whole first sheet
obj_GMGSL.load_sheet("YOUR_SHEET_ID", "", function(data) { ... });
// Specific tab
obj_GMGSL.load_sheet("YOUR_SHEET_ID", "123456789", function(data) { ... });

Executable Functions (very powerful!)

name	callback
Banana	on_collect("banana", 12)
SpeedUp	activate_powerup("speed", 5)

if (_gmgsl_is_function_object(item.callback)) {
    item.callback.call();                 // run with original params
    // or override:
    item.callback.call(["cherry", 999]);
}

Supports up to 8 parameters.
For more → pass struct/array as one parameter.

Debug & Utility Functions

• _gmgsl_debug_sheet_data(data) — detailed + types
• _gmgsl_debug_sheet_data_compact(data) — compact view
• _gmgsl_debug_sheet_data_summary(data) — column types
• _gmgsl_debug_call_all_functions(data) — run all callbacks
• _gmgsl_is_function_object(value) — check function object

Supported Data Types

Type	CSV example	GameMaker result
String	Banana or "Hello World"	string
Number	42 or 3.14 or -9	real
Array	[1,2,3] or ["fire","ice"]	array
Struct	{hp:100, name:"goblin"}	struct
Function	heal_player(30)	function object with .call()

Troubleshooting

"Function not found" → create functions as Script assets

Data not loading → must publish as Web page, never CSV

Tips & Best Practices

• Use simple lowercase column names (item_name, base_price)
• Validate data after loading
• Store result in global variables
• Load during game start / loading screen
• Keep backup of sheet structure

Made with ❤️ for the GameMaker community
MIT License — free to use in any project

Note about GenAI: Claude was used to solve a small bug I encountered at the end of the development. The rest was handmade developed.