>>I am thinking about how to create business objects (to paraphrase William Hunt, “I don’t have a formal computer training” <g>) and would like to know if I am on the right track.
>>
>>The following is a very simplified example.
>>
>>Say, I want to create a business object for conference room reservation program. One business object I will need is Reservation Class/Object.
>>
>>I think I will need to create a class (in VFP, based on a form class so that it would have private data session) with custom properties such as:
>>Room No
>>Reservation Date
>>Time From
>>Tim To
>>Reserved For
>>Etc.
>>
>>The class would also have methods, such as:
>>Check if room already booked
>>Save reservation.
>>
>>Here how the business object will be used:
>>1. User enters information into a data entry form.
>>2. Data entry form creates an object of the Reservation Class.
>>3. Reservation Class object properties are then set with values from data entry form controls.
>>4. Reservation Class method “Check if room already booked” is called.
>>5. Reservation Class method “Save reservation” is called.
>>
>>Would the above description be “in line” with how to create business objects with VFP?
>>
>>Thank you for any comments. Also, if someone wants to recommend a basic/beginners book or a white paper on creating business objects, I would appreciate very much.
>
>Dmitry,
>
>Let me add to what Craig told you.
>
>It appears that you're using the form class in order to have access to the dataenvironment and private datasession. However, in a typical n-tier design, is something like this:
UI < -- > BO < -- > Data
The double headed arrows show the communication path.
>
>You can achieve a private datasession via the session class, and, in VFP 8.0 have the ability to sub-class a dataenvironment independently of a form.
George,
I understand what you are saying. Since I am making just baby steps in n-rier application I thought, at this phase, I would combine BO and DATA in one tier. Basically, I want to keep all code in the same place rather than all over the UI methods. And since I still work with VFP 6 (even though I have VFP 8) I didn't know of the private datasession independent of the form feature.
Thank you very much for your help.
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