Using Add Module... to import a Model file
An Analytica (*.ana) file may contain a Model, Module, or Library as its top level object. (Any of these objects may, of course, contain subModules.) A Model file, unlike a Linked Module or Library, usually contains settings for various System variables (such as Time and SampleSize) and Preferences, set in the Preferences and other dialogs. When running a Model M1 and you use Add Module... to import a Model file M2, it shows the dialog below (in Analytica 4.2.2 and later). This dialog lets you decide whether you want to retain all the current settings for M1 (answer "Yes") or apply any nondefault settings from M2 (answer "No").
Answering Yes reads in the system variable settings from the imported file, answering no leaves your current system variable settings in tact.
If you are linking (rather than embedding), the model will remember your answer. However, beware that a linked file may be saved if it is dirtied in any way, thus causing the system variables in the file to be replaced. Also, when linking, the checkbox at the bottom appears, giving you the option of converting the top-level object in the file being linked to a linked module. Note that this will cause the system variable settings to be lost when the model is saved.
In general, if you intend a file to be shared between models, don't use a Model class. Change the class of the top-level object to LinkModule or LinkLibrary.
Proposed revised text for dialog
You are importing a Model file:
<model file name>
Because this file contains a Model (not just a Module or Library), it includes settings or preferences for some system variables-- such, as Time and Samplesize. Do you want to retain the settings of your existing Model rather than overwrite them with non-default settings from the Model you are importing?
[Yes] Retain current settings, and ignore settings from the Model you are importing.
[No] Update current settings with the non-default settings from the imported Model.
[Cancel] Retain current settings, and don't import the Model.
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