Differences

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--- doc:appunti:prog:kivy [2025/11/30 10:08] – [Config and Settings] niccolo
+++ doc:appunti:prog:kivy [2025/11/30 11:04] (current) – [Config and Settings] niccolo
@@ Line 186: / Line 186: @@
 Suppose that the **App** has two **Screen** objects, one called //MenuScreen// which is the main interface and one called **SettingsScreen** which allows the user to change the settings; several methods of the main App will be called automatically in this order:
-  - App.build_config()
+  - App.build_config(self, config)
-  - App.build()
+  - App.build(self)
-  - MenuScreen.on_pre_enter()
+  - MenuScreen.on_pre_enter(self)
-  - App.build_settings()
+  - App.build_settings(self, settings)
-  - App.on_start()
+  - App.on_start(self)
-The ''build_config()'' should explicitly execute ''config.setdefaults()'', which implicitly will execute a ''config.read()'' if the configuration file **my.ini** exists.
+The ''build_config()'' should explicitly execute ''config.setdefaults()'', which implicitly will execute a ''config.read()'' if the configuration file **app_name.ini** exists. The name of the file is derived from the App instance name, e.g. if the class is named MyApp, the file will be called **my.ini**.
 The ''build()'' should generally execute the ''self.create_settings()'' which automatically launches ''build_settings()'', which in turn should call explicitly the ''settings.add_json_panel()'' function.
-In this way, when the ''on_start()'' finally executes, the App can get or set config values:
+In this way, when the ''on_start()'' finally executes, the App can get or set config values using the **self.config** object, automatically instantiated:
 <code python>
@@ Line 213: / Line 213: @@
   * App.on_config_change()
-This function should call esplicitly the ''self.config.write()'', which is not handled automatically in every circumstances (e.g. when backgrounding an Android app).
+This function should call esplicitly the ''self.config.write()'', which is not handled automatically in every circumstances (e.g. if the app crashes, etc.). The config.write() is called automatically only on graceful app shutdown, only if the app detects a config change, etc. So better to stay safe and call it explicitly on config change.