dhis2-devs team mailing list archive

[Jose Garcia Muñoz <josemp10@xxxxxxxxx>]

Many thanks Knut, Jason,

Yes, I understand the two options (apps + WebAPI, and triggers). I would
like to explore a bit about the possibilities of creating and using an app.
As I have never seen one embedded into DHIS2, do you have some code example
to look at?

Of course, I will let you know about how the things are going!

Thank you!
Jose


On Fri, Jul 19, 2013 at 3:58 PM, Jason Pickering <
jason.p.pickering@xxxxxxxxx> wrote:

> Hi Jose,
>
> There are many ways to skin a cat, and as Knut says, creating an "App" is
> one way to possibly achieve this. I personally have no idea how to do this,
> but could imagine it would be possible in some way.
>
> Maybe Lars or the other devs can comment, but I am thinking the easiest
> way would be to somehow calculate your indicator when the "Complete" button
> is pressed, and save this effectively as a data value. This indicator might
> take the form of  a hidden field, but would be posted back to the
> application and saved as a normal data value when the "On-complete" button
> is pressed. The advantage with this of course is that all of the values
> would be available through the normal analytics resources. I do not know
> exactly how this could be done, but if the indicator would be calculated on
> the fly and then effectively treated as a data value and posted back to the
> application when the complete button is pressed, it would seem to be the
> easiest method I think. Since indicators can already be inserted into a
> form, it would seem like little code required to calculate the value from
> the data elements, and then post it back through the WebAPI and save it as
> a data value. Again, just hypothesizing, but it would seem to be possible.
>
> The other option (which I would likely prefer given my choice of tools)
> would be a trigger which would happen when a record is inserted into the
> "completedatasetregistration" table. This happens when the user completes
> the records, so it is certainly possible to create a trigger from such an
> action. Thinking though the code, you could detect when  a record is
> completed, and then create a stored procedure to calculate the indicator
> from  the values. I see a few problems with this though, and one of them is
> the parsing of the indicators. There are robust methods to do this in Java,
> but you would need to develop methods to parse out the indicator into
> something which could be used with PLSQL. Not really sure it would be worth
> it.
>
> Would be interested to see what you come up with.
>
> Regards,
> Jason
>
>
>
> On Fri, Jul 19, 2013 at 12:37 PM, Jose Garcia Muñoz <josemp10@xxxxxxxxx>wrote:
>
>>
>> Many thanks Jason,
>>
>> we plan to present the information to the users as dataelements
>> associated to a period, Org. unit, and forms. So, we have different forms
>> with a questionnaire and for each one we create also a dataelement, not
>> editable for the users, to store the value of the indicator. This was the
>> initial plan. So, when the indicator (score) is calculated we want to
>> "copy" that value inside the that dataelement (using a trigger in the
>> database).
>>
>> The ideal solution would be to generate all this process automatically
>> when the user completes the questionnaire, but I think that it is not
>> possible right? So, in my understanding the options are:
>>
>> 1) As you said before, run the datamart, and with a trigger get the value
>> of the indicator already stored in the database, and copying to our
>> dataelement.
>>
>> and maybe...??
>>
>> 2) Create a script that could use the analytic API to get the current
>> value of the score. Could be also a valid approach?
>>
>> Maybe I am missing something (I am not an expert in this area of DHIS2),
>> Any other ideas or suggestions?
>>
>> Thanks
>> Jose
>>
>>
>> On Sun, Jul 14, 2013 at 10:07 PM, Jason Pickering <
>> jason.p.pickering@xxxxxxxxx> wrote:
>>
>>> Hi Jose,
>>> The completeddatasetgregistration object is not really important in this
>>> case (well it might be, but not sure). The point I was trying to make was
>>> the use of triggers when a value is inserted into a table. I have not
>>> started to pick apart the analytics stuff yet to even know whether or not
>>> the values actually exist there but I suppose you could use the datamart to
>>> get the value, and then create an auditing mechanism to keep track of all
>>> values. The problem with the auditing tables is they typically tend to be
>>> really huge, so I am sure the procedure would need to be significantly
>>> different than what I have illustrated, but the approach might be worth
>>> attempting. Probably not really challenging from a code standpoint, but
>>> making sense of what comes out of the SP, and presenting it back to the
>>> users in a digestible format might be a big challenge.
>>>
>>> Regards,
>>> Jason
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> On Sun, Jul 14, 2013 at 9:48 PM, Jose Garcia Muñoz <josemp10@xxxxxxxxx>wrote:
>>>
>>>>
>>>> Many thanks Jason, Bob,
>>>>
>>>> Bob, I get your point, but the tricky part is that the final score is
>>>> not calculated as a sum of the answers of the dataset, because also each
>>>> question (I mean each "trueOnly" DE) has associated a weight, so the final
>>>> score is = W1*Q1 + W2*Q2 + ... Wn*Qn. So in the future not only the number
>>>> of questions could change (that will be slightly easier to deal with, as
>>>> you could define a generic SP no matter the number of questions the dataset
>>>> contain), but also the weights could change and there is no chance to
>>>> generalize the formula. So that was my reason to try to define one
>>>> indicator (with a formula defined by the local DHIS users), copy the
>>>> indicator value into a dataelement, as the formula could change in the
>>>> future but still we need to maintain the old values of the scores.
>>>>
>>>> Jason, we don't know if the value is finalized but it is not really
>>>> important. What we'd like to do is to let the users to know the score of
>>>> one specific period of time no matter which formula is used in the present.
>>>> But yes, maybe one trigger on the completedatasetregistration would make
>>>> part of the job. Many thanks for the code, I will try to follow and
>>>> understand it :)
>>>>
>>>>
>>>> On Sun, Jul 14, 2013 at 9:06 PM, Jason Pickering <
>>>> jason.p.pickering@xxxxxxxxx> wrote:
>>>>
>>>>> Hi Jose,
>>>>> I do not understand exactly what you are trying to do. It sounds a bit
>>>>> tricky, but if I understand correctly, you would like to somehow preserve
>>>>> the original state of your indicator, in spite of the fact that you may
>>>>> want to change it at a later point in time. I think this is particularly
>>>>> difficult to do. Creating a table of inserted values is fairly simple using
>>>>> a function similar to the one below. This SP will insert records into a
>>>>> separate table called "pricate.completeddatasetregistration_new_records,
>>>>> whenever a record is inserted into the "completeddatasetregistration"
>>>>> table. This is a pretty typical approach to create an audit table. I am
>>>>> guessing that you could create an audit table of your indicators, and then
>>>>> create a separate function to prune out all values except the first one
>>>>> (which would know through a time stamp). However, the problem with this
>>>>> approach is, you may not really know if this value is the "final" value or
>>>>> not; the data might change, and in this case, the indicator value would
>>>>> need to change (but not because of a change to the indicator formula).
>>>>>
>>>>> Sounds pretty complex to me. How do you know when the value is
>>>>> finalized and will never be changed again?
>>>>>
>>>>> Regards,
>>>>> Jason
>>>>>
>>>>>
>>>>> SQL below..
>>>>>
>>>>> Here is the SP which inserts the records into another table.
>>>>>
>>>>> CREATE OR REPLACE FUNCTION completedatasetregistration_new()
>>>>>   RETURNS trigger AS
>>>>> $BODY$
>>>>> DECLARE
>>>>>  changed boolean;
>>>>> BEGIN
>>>>>
>>>>>    INSERT INTO
>>>>> private.completedatasetregistration_new_records(datasetid,
>>>>> periodid,sourceid,
>>>>> date, storedby)
>>>>>    VALUES (new.datasetid, new.periodid,new.sourceid,
>>>>> now(),new.storedby);
>>>>>    RETURN new;
>>>>>
>>>>> END;
>>>>> $BODY$
>>>>>   LANGUAGE plpgsql VOLATILE
>>>>>   COST 100;
>>>>> ALTER FUNCTION completedatasetregistration_new()
>>>>>   OWNER TO postgres;
>>>>>
>>>>> Here is the trigger function  attached to the
>>>>> "completeddatasetregistration" table...only after an insert.
>>>>>
>>>>>
>>>>> CREATE TRIGGER inserts_completedatasetregistration
>>>>>   AFTER INSERT
>>>>>   ON completedatasetregistration
>>>>>   FOR EACH ROW
>>>>>   EXECUTE PROCEDURE completedatasetregistration_new();
>>>>>
>>>>>
>>>>> On Sun, Jul 14, 2013 at 8:40 PM, Jose Garcia Muñoz <josemp10@xxxxxxxxx
>>>>> > wrote:
>>>>>
>>>>>>
>>>>>> Thanks Bob!
>>>>>>
>>>>>> You are right in the sense that the indicator becomes redundant, but
>>>>>> I think we will still need it because we can train the end-users in the use
>>>>>> of formulas and indicators inside DHIS2, but stored procedures is quite
>>>>>> hard if they don't have much technical skills. So the idea I think is to
>>>>>> define a function in plpgsql to make a copy of the value of the indicator
>>>>>> into the dataelement (knowing the period and source of course) linking the
>>>>>> function to a trigger. Please correct me if I am wrong, as I don't have
>>>>>> much experience using triggers.
>>>>>>
>>>>>> Also, when you introduce an indicator into a dataset, when does the
>>>>>> indicator update its value? (when you click in the complete button of the
>>>>>> dataentry maybe?) and which table stores the value of the indicator?
>>>>>> (attributevalue?)
>>>>>>
>>>>>> Thanks
>>>>>> Jose
>>>>>>
>>>>>>
>>>>>> On Sun, Jul 14, 2013 at 12:40 PM, Bob Jolliffe <bobjolliffe@xxxxxxxxx
>>>>>> > wrote:
>>>>>>
>>>>>>> Hi Jose
>>>>>>>
>>>>>>> Copying to devs list as there may be greater wisdom there :-)
>>>>>>>
>>>>>>>  I think your approach can work .. ie store your historical scores
>>>>>>> as dataelement.
>>>>>>>
>>>>>>> Regarding regenerating the formula, again I think you are right and
>>>>>>> will have to resort to a database function as I can't think of an easy
>>>>>>> workaround through the application and you really don't want to do these
>>>>>>> manually.
>>>>>>>
>>>>>>> Though I start to think that if you go down this route perhaps the
>>>>>>> indicator becomes redundant.  You will have your formula as stored proc in
>>>>>>> database and can probably use that to populate your "score" dataelement
>>>>>>> directly.
>>>>>>>
>>>>>>> Bob
>>>>>>>
>>>>>>>
>>>>>>> On 14 July 2013 12:15, Jose Garcia Muñoz <josemp10@xxxxxxxxx> wrote:
>>>>>>>
>>>>>>>>
>>>>>>>> Hi guys,
>>>>>>>>
>>>>>>>> How are you doing?
>>>>>>>>
>>>>>>>> first at all, maybe I should send this email to the dev user list,
>>>>>>>> if so, sorry about that and please feel free to resend it.
>>>>>>>>
>>>>>>>> I am dealing with several forms in DHIS2 with all its DE of the
>>>>>>>> "trueOnly" type value. For each form, one final score is calculated
>>>>>>>> depending on the number of questions answered by the users and one weight
>>>>>>>> associated for each question. Of course, we have defined an indicator to
>>>>>>>> calculate this value. But, what about when the number of questions (or the
>>>>>>>> different weights) change along the time (so the formula needs to be
>>>>>>>> redefined) and we still need to maintain the historical score of the "old"
>>>>>>>> formulas?
>>>>>>>>
>>>>>>>> We were thinking about the possibility of creating a data element
>>>>>>>> for each form to store the historical scores. Does it make sense? If so,
>>>>>>>> the big challenge will be the connection of the indicator (when its value
>>>>>>>> is calculated) with the Data Element. Some ideas about how could I deal
>>>>>>>> with this? Create a trigger inside the database (with an 'on completion'
>>>>>>>> event)?
>>>>>>>>
>>>>>>>> Best regards
>>>>>>>> Jose
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
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>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>