OGR : non styled image is returned when STYLEITEM "AUTO" is used with data are specified

[elzouavo]

I use MapServer 5.2 from ms4w. I have a tab file. STYLEITEM "AUTO" works fine until I specify DATA. The raster returned by MapServer is not styled when I use STYLEITEM "AUTO" and when DATA are specified. If a replace STYLEITEM "AUTO" with a CLASS/STYLE block it works fine.

Example :

• raster is OK with STYLEITEM "AUTO" and no DATA specified

    LAYER
      NAME c_Pays
      STATUS ON
      DUMP true
      TEMPLATE "blank.html"
      TYPE Polygon
      TOLERANCE 0
      TOLERANCEUNITS pixels
      CONNECTIONTYPE OGR
      CONNECTION "Pays.TAB"
      STYLEITEM "AUTO"
      CLASS
        NAME Pays
      END
      METADATA
        WMS_TITLE "Pays"
        WMS_EXTENT "290606.951595 2390636.950133 373819.981869 2534043.950618"
        ows_include_items "ID_PAYS,NOM_DE_PAYS,AVANCEMENT"
        gml_include_items "ID_PAYS,NOM_DE_PAYS,AVANCEMENT"
        gml_ID_PAYS_alias "ID_PAYS"
        gml_NOM_DE_PAYS_alias "NOM_DE_PAYS"
        gml_AVANCEMENT_alias "AVANCEMENT"
      END
  #    DATA "SELECT ID_PAYS,NOM_DE_PAYS,AVANCEMENT FROM Pays"
    END
  

• raster is KO with STYLEITEM "AUTO" and DATA specified

    LAYER
      NAME c_Pays
      STATUS ON
      DUMP true
      TEMPLATE "blank.html"
      TYPE Polygon
      TOLERANCE 0
      TOLERANCEUNITS pixels
      CONNECTIONTYPE OGR
      CONNECTION "Pays.TAB"
      STYLEITEM "AUTO"
      CLASS
        NAME Pays
      END
      METADATA
        WMS_TITLE "Pays"
        WMS_EXTENT "290606.951595 2390636.950133 373819.981869 2534043.950618"
        ows_include_items "ID_PAYS,NOM_DE_PAYS,AVANCEMENT"
        gml_include_items "ID_PAYS,NOM_DE_PAYS,AVANCEMENT"
        gml_ID_PAYS_alias "ID_PAYS"
        gml_NOM_DE_PAYS_alias "NOM_DE_PAYS"
        gml_AVANCEMENT_alias "AVANCEMENT"
      END
      DATA "SELECT ID_PAYS,NOM_DE_PAYS,AVANCEMENT FROM Pays"
    END
  

• raster is OK with DATA specified and CLASS/STYLE block used

    LAYER
      NAME c_Pays
      STATUS ON
      DUMP true
      TEMPLATE "blank.html"
      TYPE Polygon
      TOLERANCE 0
      TOLERANCEUNITS pixels
      CONNECTIONTYPE OGR
      CONNECTION "Pays.TAB"
      CLASS
        NAME Pays
        STYLE
          SYMBOL ligne_continue
          SIZE 2.0
          OUTLINECOLOR 255 0 0
        END
      END
      METADATA
        WMS_TITLE "Pays"
        WMS_EXTENT "290606.951595 2390636.950133 373819.981869 2534043.950618"
        ows_include_items "ID_PAYS,NOM_DE_PAYS,AVANCEMENT"
        gml_include_items "ID_PAYS,NOM_DE_PAYS,AVANCEMENT"
        gml_ID_PAYS_alias "ID_PAYS"
        gml_NOM_DE_PAYS_alias "NOM_DE_PAYS"
        gml_AVANCEMENT_alias "AVANCEMENT"
      END
      DATA "SELECT ID_PAYS,NOM_DE_PAYS,AVANCEMENT FROM Pays"
    END
  

[dmorissette]

Alan, can you please try to reproduce and check this when you have a chance?

[aboudreault]

Sure, i will investigate on this as soon as possible, probably this week.

[aboudreault]

The problem not seems to be related to style item auto. I noticed that the problem could be in the OGR_DS_ExecuteSQL or OGRGenSQLResultsLayer function. If the layer is get by the OGR_DS_GetLayer function, there is no problem: the style string will be get via the TABRegion class. However, using the OGR_DS_ExecuteSQL function will result to a style string get via the OGRFeature class, so no style string.

Frank, do you have an idea of what we could do for solve this ?

[warmerdam]

Daniel,

I can imagine two approaches. One is to modify the generic sql stuff to copy style strings when doing a SELECT (much as it now copies geometry even though they aren't in the request). The other approach would be to require the user to explicitly mention the special name for the OGR style string field in their SELECT and have a way for MapServer to use style strings in regular fields (something I prototyped for a client earlier this year and that I think has broader application).

But - right now a user cannot use SELECT statements in an MapServer DATA statement and still get style strings for the features.

[aboudreault]

It bug has been fixed in gdal/ogr and will be included in gdal 1.6.1. The first approach has been adopted. The StyleString of the features are now copied like the geometry.

See related bug:  GDAL Ticket 2808