Unique Value for Attribute? Embedded forms?

lighthorse

I'm just testing Aware IM out, it's interesting to say the least. I can see a lot of efficiencies to the approach taken. We're software devs, quite used to having coding and SQL so we're trying to see if we have to trade away too much.

One question I have is about unique values for attributes. The Library example application has a rule that keeps RegularUsers LoginName unique

If EXISTS SystemUser WHERE (SystemUser.LoginName=ThisRegularUser.LoginName AND SystemUser.ID<>ThisRegularUser.ID) Then
REPORT ERROR 'User with this login name already exists. Please choose a different name'

In most modern 'regular' databases, configuring a table column so that it only allows unique values would be a checkbox setting. Aware IM seems to require 'coding' for the same thing...but of course it's not really quite the same thing, as Aware IM is handling the entire stack including user interface. Still I wonder that why it takes a rule, and it's a checkbox in Aware IM like the 'required' setting?

Second question, and this might become obvious as I read more in the docs, but can one create a page that combines views and forms, ie has multiple outputs on it? In the example apps so far the interface is usually a single form for a single purpose. Just curious as to how versatile it can be.

lighthorse

Meant to say "Still I wonder that why it takes a rule, and it's --NOT-- a checkbox in Aware IM like the 'required' setting? "

aware_support2

Using a rule gives you more flexibility when checking for unique values. The rule you mentioned in your post is a good example. It checks for a unique login name across multiple objects (tables) that are members of group SystemUser. The users of an application may be represented by different objects, like Customer, Partner, Staff, etc. Using group SystemUser in the rule causes the system to perform uniqueness check across all of these tables. Note, that the system adds the login name check rule automatically to an object when you make the object a member of SystemUser group.

For simple situations where unique value must be ensured only for a single object, I guess you are right, a check box in the attribute properties dialog could be useful. It makes little difference though, since the system uses the settings of other check boxes (like "Value must be provided" or "Calculated") to create auto-generated rules that actually do the checking. As you noted, Aware IM is a high-level system and it uses rules not only on the backend, but certain rules are also transferred onto the UI client (browser), for example to check required values on the spot without sending a request back to the server. You can see the auto-generated rules by turning on the option when looking at object rules in the Configuration Tool.

Pages that combine different data elements can be implemented either using the business object presentations (see Aware IM User Guide) or custom forms. Currently the support for custom forms is fairly limited, however we will be releasing a new version shortly that will have AJAX support. With the new version you will be able to add custom pages using AJAX framework of your choice.

lighthorse

I probably shouldn't have used the bog (if that's the acryonym for bo group) as an example rule. If there was a bo called Invoice, one would often need a unique key constraint on the Invoice Number. Using that simpler example, is there some design reason that Aware IM couldn't have had a 'checkbox' unique value constraint, just as it has for required value? You tried to lay it out for me but I didnt' quite get the rationale. If Aware IM had implemented that sort of checkbox unique key constraint switch, I guess it's be another auto-generated rule. Is there a reason for not handling that way, or just isn't?

Aware IM is very interesting, I'm glad I ran into it. Is the approach an 'invention' by you folks, or is this a manifestation of some guiding oo software design approach? Kind of a vague question I know. It's an impressive tool, I'm glad I ran in to it.

aware_support2

We have added Unique Value checkbox to our TODO list. There is no reason why it cannot be implemented using a checkbox. It just was not high enough on our priority list.

Aware IM is based on modern software engineering approaches like the object-oriented paradigm and Rete algorithm-based rule engine (see http://www.awareim.com/technology.html for more details). However, the implementation is entirely original. Its flexible and extendible architecture, the use of serious database engines and Internet technologies integrated into a complete self-contained system, makes Aware IM a unique development tool.

emendez

Is the approach an 'invention' by you folks, or is this a manifestation of some guiding oo software design approach?

May I add that it is a nice example of the naked objects approach? 🙂

Eduardo.

lighthorse

Question, how far off is the ajax enabled version, and if I license aware im now, will the updated version be available to me at no cost?

lighthorse

I see that the terms include product updates for the first year after purchase. Still curious, is the ajax stuff just a couple of months off, or longer?

aware_support

AJAX stuff will be available within 2 months (maybe sooner). Yes, you are eligible for free upgrades for 12 months, so you can linense the software now and start creating your application.

lighthorse

Sounds good...I didn't posit my question very well, so just to be clear, what I'm most interested in is flexibility with forms, ajax or not. It sounds like the new aware im features will include more in the way of custom forms, which is good. I don't really have a handle on what aware im is capable of even now but one of the few hesitations I have re the product is hoping that the form interface isn't too rigid in it's presentation.

aware_support

Aware IM forms are reasonably flexible right now - you can change the layout, add your own HTML cells, add separators etc. You can also provide your own HTML forms (with some limitations at the moment).

With the new functionality you will be able to provide your own AJAX forms as well. Aware IM will offer XML interface that will allow you to get and post the data from the server and then you will be able to present the data in whatever way you like. You can use any existing AJAX frameworks to create your own forms or write your own HTML forms using AJAX to populate controls and submit the data. Aware IM will offer a number of JavaScript functions to make populating controls and submitting the data as easy as possible.

aware_support

AJAX support is now available in version 2.1 that has been released yesterday.