Query bounds Mapserver

[mepdr]

Quering a Mapserver layer service for bounds like:

query.where("1=2").bounds(function(error, latLngBounds, response){
    map.fitBounds(latLngBounds);
});

I got

Uncaught Error: Invalid LatLng object: (NaN, NaN)(…)L.LatLng 
@ LatLng.js:24L.latLng 
@ LatLng.js:128T 
@ Util.js:32(anonymous function) 
@ Query.js:139(anonymous function) 
@ Service.js:96s.onreadystatechange 
@ Request.js:75

The server response is: {"extent":{"xmin":"NaN","ymin":"NaN","xmax":"NaN","ymax":"NaN"}}
The same against a featureServer, (i,e, https://services.arcgis.com/rOo16HdIMeOBI4Mb/arcgis/rest/services/stops/FeatureServer/0/query?returnGeometry=true&where=1=2&outSr=4326&outFields=*&returnExtentOnly=true&f=json) returns
{"extent":null}

Running arcgis 10.4
Live example http://jsbin.com/tatadejiya/1/edit?html,console,output

[rowanwins]

Hi @mepdr

Why would you run a query where("1=2") , it seems to me that that would never return any features? If you'd like to return all features you should adjust your query to where("1=1").

You can see that that returns a legitimate result
https://services.arcgis.com/rOo16HdIMeOBI4Mb/arcgis/rest/services/stops/FeatureServer/0/query?returnGeometry=true&where=1=1&outSr=4326&outFields=*&returnExtentOnly=true&f=json

Does that help?

[mepdr]

@rowanwins "1=2" is just an example for common situations in which the where clause doesn't return any feature. Beside the where clause used, .bounds() should not fail

[rowanwins]

Hi @mepdr

From what I can see from your description I would say this is expected behaviour, how could you have a valid latLngBounds if you aren't returning any features?

If it we're me I'd probably be doing something like

query.where("1=2").bounds(function(error, latLngBounds, response){
    if (error) {
         return;
     }
    map.fitBounds(latLngBounds);
});

It might help to see a jsfiddle

[mepdr]

Unfortunately the issue is exactly that .bound() fails without calling the function. As a result, any code you place in the function to handle the error is not executed at all.
I'd create a jsfiddle but I haven't got any public service available. The one I founds exposing a Mapserver service doesn't support query.

[rowanwins]

Esri has a stack of sample servers which are good for this sort of thing eg
http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/TaxParcel/TaxParcelQuery/MapServer
http://sampleserver3.arcgisonline.com/ArcGIS/rest/services

[mepdr]

Live example here: http://jsbin.com/tatadejiya/1/edit?html,console,output

[rowanwins]

http://jsbin.com/jevonemuju/1/edit?html,console,output

I've adjusted your snippet and move the setWhere() to before the query method and it now works

[mepdr]

@rowanwins .query() doesn't work in that way. In your example .bounds() returns the bounds containing all features, which is not the requested behavior because the where clause is not considered at all.
If you replace .bounds() with .ids() you'll get all features, see http://jsbin.com/liqufekeva/1/edit?html,console,output

[rowanwins]

ah I'm finally with you sorry @mepdr

So it looks like we just need to add an extra check here to make sure that response.extent is actually checked a bit more thoroughly

[jgravois]

@mepdr what behavior would you prefer to see?

• an error in the callback?
• a valid bounds object? ex: L.latLngBounds([0,0],[0,0])?

the codebase is open source and @rowanwins has pinpointed the correct location to pin a fix, so it doesn't need to be me doing the patching.

[mepdr]

IMHO the behavior should be the same there is for a featureServer service.

[jgravois]

makes sense to me.

turns out this isn't a MapServer vs. FeatureServer thing. its a hosted feature service query vs. ArcGIS Server feature service query thing.

https://services.arcgis.com/rOo16HdIMeOBI4Mb/ArcGIS/rest/services/Building_Footprints_pdx/FeatureServer/0/query?where=1=2&returnExtentOnly=true&f=json

{"extent":null}

http://sampleserver6.arcgisonline.com/arcgis/rest/services/CommercialDamageAssessment/FeatureServer/0/query?where=1=2&returnExtentOnly=true&f=json

{"extent":{"xmin":"NaN","ymin":"NaN","xmax":"NaN","ymax":"NaN"}}

i've proposed a patch in #885 and asked our devs to consider making sure the ArcGIS Server response matches the hosted feature service response in the future.

thanks for the report.

[rowanwins]

Nice work @jgravois finding that difference between the AGO and the ArcGIS Server responses, nice little quirk that had the potential to cause a few headaches!

[jgravois]

going forward we will pass both the null LatLngBounds and an error indicating that the geometry is invalid, no matter which form of the geometry we encounter in the service itself.