Glossary

The manual uses one word for one thing. This page says what each word means, in two sentences, and links the page that explains it in full.

The Words

Word	What it means
App	One ABAP class that implements z2ui5_if_app. It has one method, main. → Hello World
main	The one method of an app. The framework calls it once for every click. → Life Cycle
client	The object main receives. Every call an app makes to the framework goes through it: show a view, bind a field, read the event. → Client API
Roundtrip	One click, from start to end: the browser sends a request, main runs once, the answer comes back. One click is one roundtrip is one HTTP request.
App instance	The object of your app class while main runs. It lives for one roundtrip only.
App draft	The saved copy of the app instance. After every roundtrip the framework writes the instance to the table z2ui5_t_01, and reads it back before the next one, so the attributes keep their values. Often just "the draft". It is not a RAP draft: it holds no business data model, and it has nothing to do with with draft in a behavior definition. → RAP draft handling is the other meaning
Stateless	The normal mode: no ABAP session waits between two clicks, the app draft carries the state. Stateful is the exception, where one session stays open for one user. → Statefulness
View	The screen, written as a UI5 XML view. The app builds it as a string and hands it to client->view_display( ). → View Definition
View builder	The class z2ui5_cl_ui5_view_builder that writes the XML for you. Four methods: ele( ) adds a control and moves into it, tag( ) adds a control and stays, a( ) sets one attribute (n = name, v = value), end( ) moves back up.
Model	The data the view shows, sent to the browser as JSON. It is made of the attributes the app has bound.
Binding	The link between a public attribute of the class and a property of a control. _bind( ) shows the value and, for an input control, brings back what the user typed. → Data Binding
Event	What the user did, sent to main: a button press, a row click. _event( ) attaches an event name to a control, check_on_event( ) asks for it. → Backend events
Frontend action	Something the browser does without calling main: set the focus, copy to the clipboard, open a URL. Called with follow_up_action( ), as a statement or as the value of an event attribute. → Frontend actions
Sub-app	An app started by another app with nav_app_call( ). When it ends with nav_app_leave( ), the calling app continues. → Navigation
Popup, popover	A dialog over the view, and a small bubble next to one control. Each is a view of its own, shown with popup_display( ) and popover_display( ). → Popup
Frontend	The part that runs in the browser: one generic UI5 app that shows whatever view and model it receives. It is the same for every app and contains no app code.
HTTP handler	The ABAP class behind the endpoint. It passes every request to the framework. You create it once, in the Quickstart.
Endpoint	The URL of the HTTP service that serves abap2UI5: an ICF node on an on-premise system, an HTTP service in ABAP Cloud.
User exit	A class of your own that implements z2ui5_if_ui5_exit. It configures the installation: UI5 source, theme, security settings. It is not a classic SAP user exit. → User Exits
Startup page	The page the endpoint shows when no app is named. It checks a class name and starts the app.

Words You May Know from Elsewhere

If you know	then in abap2UI5
PBO and PAI of a dynpro	one call of main: it reacts to the event and builds the answer
a selection screen parameter	a public attribute bound to an input with _bind( )
CALL SCREEN	nav_app_call( )
a UI5 controller	the app class
an OData service per app	nothing: one endpoint serves every app
a RAP draft	still a RAP draft, used through EML. The app draft is something else, see above