Core Application Files

A Levure application employs at least four core files when it is running: three LiveCode stacks and a YAML text file named app.yml. Each core stack has a file name that you see in your application project folder and a stack name that is used when the stack is open in your application.

File Name	Stack Name
standalone.livecode	LevureStandalone
levure.livecodescript	LevureFramework
app.livecodescript	app
app.yml

Let's look at each of these core files:

LevureStandalone

LevureStandalone is the stack name of the standalone file you run to start your application. The standalone file can be either standalone.livecode in development or a standalone executable built from standalone.livecode in your packaged distribution build.

The purpose of LevureStandalone is to load the LevureFramework stack as a behavior. This is why you must always start a Levure application with the standalone. Once LevureFramework is loaded it takes over and handles the application startup from there.

Important note for HTML5! If you are building for HTML5 then you will need to resize the LevureStandalone stack to be the size that you want your presentation to appear at in the web browser. LiveCode looks at the size of the stack being built as a standalone when determining the size of of the LiveCode app on the web page.

• Learn about LevureStandalone

LevureFramework

LevureFramework is the stack name of the levure.livecodescript script-only stack that has the primary framework functionality. When you start an application with the standalone, LevureFramework is opened as a behavior of LevureStandalone and is put into the message path as a global library with start using.

When LevureFramework is first loaded it reads the settings in the app.yml file into an array and uses that information to manage the startup of your application. The framework loads libraries, behaviors, frontscripts, backscripts, helpers, extensions, externals, and user interface stacks based on the settings in app.yml.

After startup, while your application is running, you interact with LevureFramework handlers and functions through the Levure API.

• Learn about LevureFramework

app

app is the stack name of the app.livecodescript script-only stack that allows you to control the startup and shutdown operations for your application.

The app stack receives messages from LevureFramework during application startup and shutdown and has a handler for each message. You will edit the handlers in the app script to control when your application initialization and cleanup operations are called.

• Learn about the app stack

app.yml

The app.yml file is a YAML text file where you specify all the configuration settings for your application. This file sits alongside the standalone.livecode and app.livecodescript stack files in your app folder. To modify this file for your application, you will use the text editor of your choice.

LevureFramework reads the settings in app.yml into an array when your application first starts up. LevureFramework then uses these settings when loading your application as well as when packaging your application for distribution.

In app.yml you specify your application UI stacks, libraries, helpers, backscripts, and frontscripts to be loaded. You can also specify any extensions and externals to be used and define settings for building and packaging your application distributions.

You can also add your own arbitrary custom settings to the app.yml file. Any settings you add will be available via the levureAppGet() function.

• Learn about app.yml

NEXT: Updating Levure