topic Re: Query Feature Layer / Create Layer from Shapefile in Qt Maps SDK Questions

Query Feature Layer / Create Layer from Shapefile

DanielBachmann1 — Tue, 12 Apr 2016 12:18:01 GMT

Hi,

I'm trying to use the runtime sdk to load a shapefile and dynamically change the geometry shown by querying the attribute table. I created an EsriRuntimeQt::LocalFeatureService for an "empty" mpk file and added the Shapefile using the approach from QtSampleApplication_10.2.6_win64 to a ArcGISDynamicMapServiceLayer. Then I created a local Feature service (pointing to the same mpk-file) and created a FeatureLayer in the slot called on layerCreateComplete().

But creating a FeatureLayer in this method like

m_featureLayer = new EsriRuntimeQt::ArcGISFeatureLayer(m_dynamicLocalServiceLayer->url()+"/0",this);

m_featureLayer->setOperationMode(EsriRuntimeQt::QueryMode::SelectionOnly);

m_map->addLayer(m_featureLayer); connect(m_featureLayer, SIGNAL(layerCreateComplete()), this, SLOT(onFeatureLayerCreateComplete()));

connect(m_featureLayer, SIGNAL(layerCreateError(QString)), this, SLOT(onFeatureLayerCreateError(QString)));

fails. None of the slots above is called.

What am I missing?

Thanks,

Daniel

Re: Query Feature Layer / Create Layer from Shapefile

DanielBachmann1 — Tue, 12 Apr 2016 16:43:36 GMT

Created the mpk-File offline in ArcMap and the FeatureLayer shows up.

!!!But it is extremely slow!!!

Layer has 900 Polylines with about 1000 points each so the raw geometry is about 7MB of raw geometrie data (shp is 11MB). But the FeatureLayer uses nearly 2GB of RAM and renders really slow.

Realtime queries on the data seam to be impossible. Is this expected behaviour? Or is it just the wrong way to online change the number of features shown in a layer?

Re: Query Feature Layer / Create Layer from Shapefile

LucasDanzinger — Tue, 12 Apr 2016 16:58:05 GMT

Something doesn't sound right. Are you trying to make an ArcGISDynamicMapServiceLayer, or ArcGISFeatureLayer? The dynamic layer should be much faster, but I see your code is for ArcGIS Feature Layer.

Re: Query Feature Layer / Create Layer from Shapefile

DanielBachmann1 — Tue, 12 Apr 2016 17:19:46 GMT

If I use a ArcGISDynamicMapServiceLayer it is much faster. But I was not able to restrict the number of features drawn from that layer, is this possible?. I'm new to the runtimeAPI, so I most likely missed something...

Re: Query Feature Layer / Create Layer from Shapefile

YueWu1 — Tue, 12 Apr 2016 17:57:24 GMT

Hi Daniel,

I don't think ArcGISDynamicLayers can restrict or limited the number of features return like ArcGISFeaturelayer. Dynamic Layer is more useful to dynamically change layer appearance and behavior in your map service. Determining which layers will appear in a map, layer symbology, layer order and position, labeling, and more, can be achieved on the server through the use of dynamic layers. In this way, dynamic layers can increase the amount of interaction that users are able to have with your maps.

Have you tried to use definitionExpression to limit the features return from ArcGISFeaturelayer first? ArcGIS Runtime SDK for Qt QML API: ArcGISFeatureLayer Class Reference

Then you can debug that event handle to see why that SLOT is not calling.

Re: Query Feature Layer / Create Layer from Shapefile

DanielBachmann1 — Tue, 12 Apr 2016 21:11:03 GMT

Hi,

so I will not be able to dynamically query Feature-Layers of that size with the runtime SDK?

All possible subsets of the Feature-Layer should be drawable... But creating the Featurelayer and showing all Features needs approx. 3 to 5 Minutes to finish on my i7 (in ReleaseMode) and as mentioned earlier uses 2gb of main memory and this is a rather small dataset.

Re: Query Feature Layer / Create Layer from Shapefile

LucasDanzinger — Tue, 12 Apr 2016 22:31:28 GMT

What specifically do you want to do? What do you mean by dynamically query? In general, ArcGISDynamicMapServiceLayer will be better for performance than the Feature Layer, because it is sending back dynamically generated images, versus complex geometries and symbols. If you need to only show features that match some given query, then you will need to use a FeatureLayer. If you can upload some sample code/project and data, that would be helpful too.

Re: Query Feature Layer / Create Layer from Shapefile

DanielBachmann1 — Wed, 13 Apr 2016 18:05:09 GMT

The layer consists of polylines which should be first shown completely. The number of polylines to show should then be limited by querying the associated attribute table. You can think of a slider which is used to restrict the maximum allowed value of one attribute resulting in a subset of "valid" features.

May be this is only achieved with the ArcObjects SDK directly?

Re: Query Feature Layer / Create Layer from Shapefile

YueWu1 — Wed, 13 Apr 2016 20:18:46 GMT

Hi Daniel,

I found this similar concept in JavaScript Raster layer slider | ArcGIS API for JavaScript

You should able to do this in RuntimeQt as well.

Re: Query Feature Layer / Create Layer from Shapefile

LucasDanzinger — Wed, 13 Apr 2016 20:42:37 GMT

Hi Daniel,

You have a few options. The first is ArcGISDynamicMapServiceLayer, and that will give better performance, but applying a definition expression is the tricky part. If the service supports dynamic layers, then you could get the dynamic layer info, and set definition expression here - https://developers.arcgis.com/qt/cpp/api-reference/class_esri_runtime_qt_1_1_layer_info.html#a8b4ab81ca398c213d40664c260d12bdb. I am trying to confirm if you can turn on dynamic layer info support or not with local services right now… I will get back to you on that.

Otherwise, you could also go the feature layer route, but it sounds like you are having some performance issues. I would try a few things for this:

- Set max allowable offset, to generalize the geometries - ArcGIS Runtime SDK for Qt C++ API: EsriRuntimeQt::ArcGISFeatureLayer Class Reference

- Limit the out fields to only what you need - ArcGIS Runtime SDK for Qt C++ API: EsriRuntimeQt::ArcGISFeatureLayer Class Reference

- Instead of ArcGISFeatureLayer, try using the GeodatabaseFeatureServiceTable and the FeatureLayer

We will soon have native support for shapefiles, so you don't need to spin up local server at all for this. It should be a very simple and straight forward way for you to do this with our upcoming release, but for now, there are unfortunately a few hoops to jump through.

Hope this helps.

Luke

Re: Query Feature Layer / Create Layer from Shapefile

LucasDanzinger — Thu, 14 Apr 2016 23:52:42 GMT

Just to follow up, with the local dynamic map service, you should be able to do definition expression. Here is how you would go about it:

- Create a local map service

- enable dynamic layers on it - ArcGIS Runtime SDK for Qt C++ API: EsriRuntimeQt::LocalMapService Class Reference

- Once the service is started and the layer is loaded, obtain the dynamic layer infos from the layer

- obtain the dynamic layer info for the associated layer you are working with

- set the definition expression on the applicable dynamic layer info - ArcGIS Runtime SDK for Qt C++ API: EsriRuntimeQt::LayerInfo Class Reference

- refresh the layer - ArcGIS Runtime SDK for Qt C++ API: EsriRuntimeQt::ArcGISDynamicMapServiceLayer Class Reference

This should work for you. Like I said, the workflow is a bit long right now, but we will soon have native support for shapefiles, and it should be very straightforward to do something like this.

-Luke

Re: Query Feature Layer / Create Layer from Shapefile

DanielBachmann1 — Fri, 15 Apr 2016 16:25:27 GMT

Hi Luke,

works perfect. Thanks a lot! As long as the performance is acceptabe, the length of the workflow is no concern.

Do you know when native support for shapefiles will be available?

-Daniel

Re: Query Feature Layer / Create Layer from Shapefile

LucasDanzinger — Fri, 15 Apr 2016 17:46:14 GMT

Ok, great! We plan on releasing Quartz final around Q3 of this year. Shapefile support will not make it into that release, so it'll be in our first update, which we are planning for 3-4 months after, so end of this year/beginning of next.

Re: Query Feature Layer / Create Layer from Shapefile

EricPflaum — Fri, 09 Dec 2016 16:54:15 GMT

Hi,

I'm new to the SDK.

At this point in time we have Qt SDK 10.2.6 and 100.0.0 available for download, and I'm not sure what Quartz refers to.

I need to import shapefiles using either the QML or C++ API, but I'm having difficulty finding documentation on how to do that.

What is the best method currently supported at this point?

Can you direct me to some examples?

Thanks,

-Eric

Re: Query Feature Layer / Create Layer from Shapefile

LucasDanzinger — Fri, 09 Dec 2016 20:47:23 GMT

"Quartz" was the codename for our 100.0 release. This is the new generation of Runtime SDKs from Esri. The 100.0 release does not yet have support for shapefiles. However, our 10.2.6 release does have a way you can view shapefiles - ArcGIS for Developers | ArcGIS for Developers

In an upcoming update of Runtime 100, we will have native support for shapefiles and it will be very easy to read and query them.