Derivations, Virtual Fields and Refresh

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Derivations, Virtual Fields and Refresh

Postby Graham Smith » Fri Feb 13, 2009 3:45 pm

There is something in WebElements that I really do not understand. Apparently, the information in a record is static - that is, it doesn't change as data is changed. For example, if I have a field (real or virtual) that is a sum of two other fields, that field derivation will not cause the record to be refreshed and display the sum.

Is that correct, or am I overlooking something obvious?
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Re: Derivations, Virtual Fields and Refresh

Postby Graham Smith » Mon Feb 16, 2009 2:20 pm

After a bit more testing, I am no further along with this than before. It seems a dead end. What's on the screen is fixed and does not respond to any changes. Same goes for subforms.
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Re: Derivations, Virtual Fields and Refresh

Postby Pete Tabord » Fri Dec 04, 2009 2:19 pm

Hi Graham

It doesn't respond field by field, no. Changes are only processed when you enter the screen. The Web, without any applets downloaded to the browser machine, acts like an old dumb terminal and only processes data when you submit the page. We do do some limited type checking field by field but that's all.

Web Elements isn't trying to implement Ffenics 'on the Web' - its simply allowing individual documents to be published 'real time'. You are properly connected to the database engine, proper locking operates etc. etc., but it operates on a web page basis, not a field by field basis.

The DataEase people ARE trying to produce something that has the full functionality of DFD 'on the Web' - we aren't. And, just as DFW could never work exactly like DFD because its under a different operating system, I expect exactly the same will be true when the operating systenm is effectively the web browser.
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Re: Derivations, Virtual Fields and Refresh

Postby tasos » Fri Dec 04, 2009 5:45 pm

Pete,
Web Elements functions as you describe up to a point.

Published Aspects operate as expected. They do allow for the same functionality as defined in the application.

There is however an issue, relevant to sub-form design.

Enquiries, based on published aspects which have been defined as Queries by Form:
- Initially the display ok
- Provide selection criteria
- Press the “Next Record” object.

This stage produces an error message instead of returning the Aspect and relevant records.

If the next record object is press second time, Web Elements display the aspect and the information as expected.

We have a number of published aspects without sub-forms running.
The above problem stopped us from publishing sub-forms.
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