dhis2-devs team mailing list archive

[Knut Staring <knutst@xxxxxxxxx>]

Forwarding to the developer list

On Thu, Oct 28, 2010 at 3:47 PM, Jan Henrik Øverland
<janhenrik.overland@xxxxxxxxx> wrote:
>> From: Knut Staring <knutst@xxxxxxxxx>
>> To summarize what I currently see as the next major GIS improvements:
>>
>> 1) Points displayed with different sizes or graphical symbols, not
>> just colored circles
>>
>> 2) Showing a lot of data for a point when clicking on it (typical use
>> case is showing a kind of profile for a health facility, for example
>> all values for a special indicator group as a first go).
>>
>> 3) Geoserver as alternative datasource for thematic layers -
>> substantial expansion of available functionality
>>
>> 4) Support for multidimensional data elements and indicators
>>
>> 5) Access control like rest of DHIS. Not everyone should be able to
>> set administrative settings
>>
>> 6) Reenabling the export to Excel and PDF (why did they disappear?)
>>
>> 7) Data import from surveys etc. - with optional automatic assignment
>> of points based on coordinates

Adding a point 8): We currently represent time as just another
dropdown box. It would be really nice to have a time slider like e.g.
Instant Atlas, ArcGIS or this (flash) example :
http://labs.slate.com/articles/slate-job-map-unemployment-rate/

In general in DHIS2, we may need to improve our handling of time
series outputs, perhaps even for input. Point 2) can be related to
time series. The user should also be able to relatively easily
calculate *differences*, e.g. between one month and the next, or even
from March 2009 to March 2010. Such differences are interesting to
map, and can show which areas seems to be improving for a particular
indicator, as in this example:
http://drop.io/inup25f/asset/unemp-change-png

> 1, 2 and 5) Covered by blueprints for 2.0.6 and 2.0.7.

Good. We may need to update them as we progress.

> 3) Geoserver is already an alternative datasource for the thematic layers in
> OHM. When it comes to expansion of functionality it would be nice if someone
> that knows Geoserver well could summarize what we could take advantage of,
> whether it requires special database add-ons like PostGIS etc.

Right, Geoserver can act as a Web Feautre Service which outputs
GeoJSON, so it is possible to upload shapefiles to Geoserver instead
of importing them (using GML) to the orgunit table. However, I was
thinking of adding a supplementary mode, which would allow for
connection to external data (e.g. in an Excel file or an RDBMS).

I see two possibilities for such an alternative mode:

1) The user's dropdown selections would be communicated to Geoserver,
and Geoserver provides the styling, rather than the styling happening
in the client, like in the previous OH functional prototype. However,
I suppose it would mean that the dropdowns would also have to be
populated from the external datasource? Needs more thought.

2) The GeoJSON file that is generated by Geoserver (by linking to
DHIS2 or other data sources) can contain all the relevant data, and
the dropdown box selections will then only be filtering (if there are
more than one indicator) and styling in the client.

Using PostGIS is in many ways the best option, especially since we are
recomending Postgres now. I think we could require it for some
advanced functionality. However, Geoserver will work nicely with
shapefiles.

I also think we have to consider how to deal with 4), as I can imagine
people will want to see a map Males vs a map of Females, for example.

> 6) PDF was removed because of the presence of image export. With the PDF
> functionality followed a lot of code, dependecies, libraries, a print
> servlet and a widget in the already crowded left side of the viewport. The
> image export solution is a lot neater and, in my opinion, covers the
> necessary functionality.
> Two months back there were some problems with the image exportation. Both
> image and Excel export were temporarily removed (the Excel sheet contains an
> image). When the problem was fixed there was a consensus that the Excel
> sheet is currently not very valuable. We may put it back in if you want.

Ok, thanks for the explanations - I think we can keep it as it is,
especially if the removal also reduced the size of the OHM
considerably, since it is by far the heaviest module.

I liked the combination of having the data along with the map as
export, but I am not sure if this is a real use case (people may
prefer a full export or a pivot table). If it is, we could just export
the data as CSV.

Point 7, on importing external data is in a way an alternative to the
Geoserver mode I discuss above. I think both options may need to be
developed, since the particular use case would favor one or the other.

Knut