[MapScript] Add $layer->getItems() method

[dmorissette]

We need a way to retrieve the list of fields available in a layer from a mapfile 
in a MapScript application.  We could open the DBF file directly using the dbase 
module, but this won't work for OGR data sources.

The cleanest solution seems to be to add a $layer->getItems() method that would 
call msLayerGetItems() at the lower level and return an array of attribute 
names, e.g.

  $layer->open($shapepath);
  $attr_names = $layer->getItems();
  $layer->close();

This should be added to both the SWIG MapScript (mapscript.i) and the PHP 
MapScript.

Do you see any potential problem with doing this, Steve?  I know this would work 
fine for SHP and OGR, but what about SDE, PostGIS, etc?

[sfournier@…]

I'm working on it....

[dmorissette]

Steve Lime wrote:
> 
> It's on my to do list for the SWIGed versions of MapScript. Problem is
> that you have to write SWIG typemaps which involves low level C code
> within a particular language. This needs to be done for each language
> supported, for sure that means perl, python, tk/tcl and java. A work
> around would be to add accessor methods to the layerObj and shapeObj get
> at item names and values for any particular shape. I thought that I'd
> already done that much.
> 
> I see no problems regardless of the datasource since the shapeObj is
> supposed to buffer the user from that complexity. Any datasource that
> supports queries (at the moment on Oracle Spatial does not) should be
> fine. I think everyone implemented a msLayerGetShape capability so...
> 
> Steve
> 


I guess we'll implement this directly in php_mapscript.c then (it's just a call 
to msLayerGetItems() + packaging the layer->items[] array after all) and we will 
reassign the bug to you Steve after so that you can close it once the required 
changes to support the SWIG version have been done.

[sfournier@…]

I added a new function 'getItems' into PHP mapscript that returns a string array of all layers items. 

Should be implemented in swig someday. That why I did not chage the bug to FIXED.

[dmorissette]

If we waited this long, we can probably wait until 4.1... let's make this a P1 
for 4.1