[Qgis-user] Questions QGIS webclient

Tue Feb 28 04:53:01 PST 2012

Hallo Andreas,

seems to be related with http://hub.qgis.org/issues/3959

the proposed double \\ works

this also worked for me:
was: ... 'BOX\(|\)','','g'),' ',',')||']'::text AS bbox ...
now: ... 'BOX[(]|[)]','','g'),' ',',')||']'::text AS bbox ...

found the hint in the first user comment at 
http://www.postgresql.org/docs/8.4/interactive/functions-matching.html#FUNCTIONS-POSIX-REGEXP

standard_conforming_strings is not set in my postgresql.conf (PostgreSQL 
8.4)

as we are into wsgi there are more questions (I have no clue about wsgi, 
but did some QGIS-extensions in Python):

1) why do you use psycopg2 instead of QtSql (additional installation 
needed as PyQt4 is installed because of QGIS anyhow)?

2) I got a runtime error because the try - except clauses in both 
scripts do continue even if the try is unsuccessful, e.g. the conn 
object is undefined if psycopg2.connect is unsuccessful. IMHO the rest 
of the code must go into the try block or the except block must return. 
What happens with the string errorText? Is it dumped in some logfile?

3) Documentation says the search table is supposed to have a field 
searchstring_tsvector (type tsvector) but it is not used, instead 
searchstring::tsvector is used!
I experimented with tsvector; the WHERE clause in search.wsgi which reads
"searchstring::tsvector @@ lower('"+querystrings[j]+":*')::tsquery"

This works fine if you have a street name like 'Am alten Gaswerk':
select 'Am alten Gaswerk'::tsvector  @@ 'Gaswerk'::tsquery returns true
select 'Am alten Gaswerk'::tsvector  @@ 'Am'::tsquery returns true

BUT
select 'Karl-Marx-Allee'::tsvector  @@ 'Marx'::tsquery returns false
select 'Karl-Marx-Allee'::tsvector  @@ 'Karl'::tsquery returns false

PostgreSQL provides to_tsvector and to_tsquery functions
select to_tsvector('Karl-Marx-Allee') @@ to_tsquery('Karl')
select to_tsvector('Karl-Marx-Allee') @@ to_tsquery('Marx')
both return true
select to_tsvector('Am alten Gaswerk') @@ to_tsquery('Gaswerk') returns 
true

BUT
select to_tsvector('Am alten Gaswerk') @@ to_tsquery('Am') returns false 
:( because Am is skipped by to_tsvector

EVEN WORSE
select to_tsvector('german', 'Über den Teufelslöchern') returns 
'teufelsloch':3, a user has to enter quite some characters before the 
query returns something and if he enters "Teufelslöcher" he won't get 
any result.

So tsvector is fine for texts skipping all the fill words and reducing 
nouns to their single form but as we are dealing with place names we do 
not want this behaviour. We could use PostgreSQL's ILIKE but this would 
result in a full string comparison and I guess in a lower performance.

My workaround was to use searchstring_tsvector and to use a different 
language for to_tsvector and to_tsquery:
CREATE VIEW ... AS SELECT ... to_tsvector('spanish', stringfield) AS 
searchstring_tsvector ...
and change search.wsgi accordingly:
searchstring_tsvector @@ to_tsquery(\'spanish\','"+querystrings[j]+":*')

select to_tsvector('spanish', 'Über den TEufelslöchern') @@ 
to_tsquery('spanish', 'Über') returns true

I can create tickets (and provide patches) for these issues.

Bernhard

Am 28.02.2012 11:42, schrieb Andreas Neumann:
> Hi Bernhard,
>
> Ok - I can see some difference in the output of your server and my
> server in the bbox format:
>
> Here is the output of my server:
> "bbox" : [696321.5, 245623.015625, 696878.875, 246087.875]
>
> and here is the output of your server:
> "bbox" : [(4472182.5, 5645202, 4472183, 5645202.5)]
>
> Note the additional round brackets in your output - which I assume that
> QGIS webclient cannot digest.
> So either the Python script of your server can get rid of these round
> brackets or we need to improve QGIS webclient to ignore them. Can you
> try on the server first?
>
> If this is not easily possible we can also try on the client.
>
> Hopefully we can improve the situation here in either the search python
> script or in the client.
>
> Andreas
>
>
> On Tue, 28 Feb 2012 10:16:08 +0100, wrote:
>> Hi Andreas,
>>
>> the server is currently not available from outside so here is the
>> wsgi-scripts' output:
>>
>> http://10.144.9.51/wsgi/search.wsgi?searchtables=kartenportal.suche_alles&query=Am%20alten%20Gaswerk&cb=bla
>>
>> bla({"results": [{"searchtable": null, "displaytext": "Strassen",
>> "bbox": null}, {"searchtable": "kartenportal.suche_alles",
>> "displaytext": "Am alten Gaswerk (Strasse)", "bbox":
>> [(4471973.5,5645101.5,4472185.5,5645205.5)]}, {"searchtable": null,
>> "displaytext": "Adressen", "bbox": null}, {"searchtable":
>> "kartenportal.suche_alles", "displaytext": "Am alten Gaswerk 1
>> (Adresse)", "bbox": [(4472041,5645209,4472041,5645209)]},
>> {"searchtable": "kartenportal.suche_alles", "displaytext": "Am alten
>> Gaswerk 2 (Adresse)", "bbox":
>> [(4472071.5,5645134.5,4472072,5645135)]}, {"searchtable":
>> "kartenportal.suche_alles", "displaytext": "Am alten Gaswerk 4
>> (Adresse)", "bbox": [(4472106,5645099,4472106,5645099)]},
>> {"searchtable": "kartenportal.suche_alles", "displaytext": "Am alten
>> Gaswerk 7 (Adresse)", "bbox": [(4472169,5645181,4472169,5645181)]},
>> {"searchtable": "kartenportal.suche_alles", "displaytext": "Am alten
>> Gaswerk 7a (Adresse)", "bbox":
>> [(4472182.5,5645202,4472183,5645202.5)]}, {"searchtable":
>> "kartenportal.suche_alles", "displaytext": "Am alten Gaswerk 9
>> (Adresse)", "bbox": [(4472187,5645130.5,4472187.5,5645131)]}]})
>>
>>
>> http://10.144.9.51/wsgi/getSearchGeom.wsgi?_dc=1330359714648&searchtable=kartenportal.suche_alles&displaytext=Am%20alten%20Gaswerk%20(Strasse)
>>
>> MULTILINESTRING((4471973.6667815 5645205.155335,4472011.32780392
>> 5645187.04378521,4472168.93332659 5645110.52723776,4472185.36362809
>> 5645101.54646928))
>>
>> I am using EPSG:31468 (QGIS project's setting, QGIS project's WMS
>> coordinate system, data srid)
>> GlobalOption.js - snippet:
>>
>> //EPSG projection code
>> var epsgcode = 31468;
>>
>> // OpenLayers global options
>> // see
>>
>> http://dev.openlayers.org/releases/OpenLayers-2.10/doc/apidocs/files/OpenLayers/Map-js.html
>>
>> var MapOptions = {
>> projection: new OpenLayers.Projection("EPSG:"+epsgcode),
>> units: "m",
>> maxScale:50,
>> minScale:150000,
>> fractionalZoom: true,
>> transitionEffect:"resize",
>> controls: []
>> };
>>
>> tooltip works now with field named "tooltip"
>>
>> Bernhard
>>
>>
>> Am 27.02.2012 22:06, schrieb Andreas Neumann:
>>> Hi Bernhard,
>>>
>>> On 02/27/2012 05:22 PM, bernhard.stroebl at jena.de wrote:
>>>> Dear all,
>>>>
>>>> I am fiddling around with QGIS server and webclient and I do like both
>>>> of them. Thank you for this software!
>>>> Whereas QGIS server's configuration is pretty straightforward QGIS
>>>> webclient is a higher hurdle.
>>>> Here are some questions (more to follow, I am sure :):
>>>>
>>>> 1) searchComboBox: I configured two search relations (views): streets
>>>> MULTILINESTRING and addresses POINT in my database and they are
>>>> searched
>>>> ok BUT the map does not zoom in at the feature chosen in the comboBox
>>>> although the geometry is highlighted on the map
>>>
>>> It really should zoom to the feature. Maybe it is an issue of map scale
>>> or units? What units and scales are you using?
>>>
>>> Do you have the search somewhere available to test or can you share a
>>> snippet from the search result?
>>>
>>> Here is a valid request on my server and the corresponding result:
>>>
>>>
>>> http://webgis.uster.ch/wsgi/search.wsgi?query=&searchtables=&query=Hasenb%C3%BCe&cb=stcCallback1003
>>>
>>>
>>> stcCallback1003({"results": [
>>> {"searchtable": null, "displaytext": "Flurnamen", "bbox":
>>> null},{"searchtable": "av_user.suchtabelle", "displaytext":
>>> "Hasenb\u00fcel (Flurname, Uster)", "bbox":
>>> [696321.5,245623.015625,696878.875,246087.875]},
>>> {"searchtable": "av_user.suchtabelle", "displaytext": "Hinterer
>>> Hasenb\u00fcel (Flurname, Uster)", "bbox":
>>> [696621.375,245924.890625,697073.5,246226.640625]},
>>> {"searchtable": null, "displaytext": "Strassen", "bbox": null},
>>> {"searchtable": "av_user.suchtabelle", "displaytext": "Hinterer
>>> Hasenb\u00fcelweg (Strasse, Uster)", "bbox":
>>> [696699.75,245958.046875,697006.375,246224.640625]},
>>> {"searchtable": "av_user.suchtabelle", "displaytext": "Vorderer
>>> Hasenb\u00fcelweg (Strasse, Uster)", "bbox":
>>> [696454.25,245665.265625,696863.6875,246017.96875]}
>>> ]})
>>>
>>>> 2) MapTips: the map tip always shows the layer's name no matter which
>>>> field I defined in my layer properties in the project. Or is the
>>>> webclient's map tip configured elsewhere?
>>>
>>> Currently it is hardwired to a column named "tooltip". You need to
>>> create an attribute or column in your table or view named "tooltip".
>>>
>>> Currently there is no way to know which column is set for the maptip.
>>> Later we will take the column name from the QGIS configuration as soon
>>> as QGIS server supports that. The current GetCapabilities request does
>>> not tell us which column is set for map tips. I think this will be
>>> available later this spring as we also want to have the ability to
>>> dynamically set map tips for QGIS client.
>>>
>>> Hope this helps,
>>> Andreas
>>>
>>> _______________________________________________
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>>>
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>>
>> --
>> Bernhard Ströbl
>> Anwendungsbetreuer GIS
>>
>> Kommunale Immobilien Jena
>> Am Anger 26
>> 07743 Jena
>>
>> Tel.: 03641 49- 5190
>> E-Mail: bernhard.stroebl at jena.de
>> Internet: www.kij.de
>>
>>
>>
>> Kommunale Immobilien Jena
>> Eigenbetrieb der Stadt Jena
>> Werkleiter: Thomas Dirkes
>>
>>
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>

-- 
Bernhard Ströbl
Anwendungsbetreuer GIS

Kommunale Immobilien Jena
Am Anger 26
07743 Jena

Tel.: 03641 49- 5190
E-Mail: bernhard.stroebl at jena.de
Internet: www.kij.de

Kommunale Immobilien Jena
Eigenbetrieb der Stadt Jena
Werkleiter: Thomas Dirkes

________ Information from NOD32 ________
This message was checked by NOD32 Antivirus System for Linux Mail Server.
http://www.nod32.com