Changes* in the properties of an object in the application setup can be saved directly manually in the current application definition (.pbk file) by right-clicking the application node which the object is part of, and choosing Save in the pop-up menu, by choosing Save (Ctrl+S) in the File menu or by clicking the Save button:

Since all sub-objects in an application are stored in one and the same .pbk file, you cannot store changes in the sub-object separately; you have to save the application structure as a whole to save the changes to an individual method, for instance.

You can also only save changes in selected files, by choosing File > Save all... (Ctrl+Shift+S) or by clicking the Save all button:

In the Save objects window that opens when you click this button, you will be presented with an overview of all the unsaved files in which you made changes, and you can determine of each of these separately whether you want to save them or not, by selecting them or deselecting them. Click Yes to save the selected files. Cancel returns you to Designer.
When you close Axiell Designer while you haven't saved all changes yet, the Save objects window will automatically appear, allowing you to save your work before the application is closed.

Note that in the Application browser only physical Adlib objects (files) can be saved separately (currently these are just the .pbk, .inf, and .fmt files). This is because sub-objects like e.g. data sources or methods, are not single files. To save changes in sub-objects immediately, save the larger file that incorporates them, like the application definition.

While managing objects in the tree view of the Application browser, there are a few actions that initiate an automatic save of the concerning object, namely the creation of an application definition, a screen file, or folder.

* The nature of properties forms and lists sometimes requires you to leave a property that you just edited, before you can save it. So when you have edited your last property for today, make sure you first click some other property or tab, before you save all your work.

Your .pbk files are safe

To prevent possible loss of .pbk files because of any errors occurring while you save an .pbk file, there is an automatic backup procedure in place. When you instruct Designer to save your work, it first makes a backup of the files to be saved by renaming the original files (meaning: the files in which you have not yet saved your current changes). Those backup files have the same name but the extension .bak. In the unlikely event that the subsequent saving of the changed .pbk file corrupts the file, this file will automatically be closed and deleted, and the .bak file is given back its original extension .pbk. Of course you must then enter your changes to the file again, and try to save it more successfully; but at least you will have a proper .pbk file.
But usually saving your files will happen without problems, and when a save has indeed been successful, the automatically created .bak files will be deleted automatically again too, as if they were never there.