topic Re: What does the query widget query? in ArcGIS API for Flex Questions

What does the query widget query?

RichardHolloway — Thu, 09 Dec 2010 20:34:24 GMT

I am new and trying to figure this out. You query a service but how do I create the items to be queried within that service? In ArcMap I can't seem to find what I am looking for. Can someone point me in the correct direction?

Re: What does the query widget query?

RobertScheitlin__GISP — Thu, 09 Dec 2010 21:45:48 GMT

Richard,

The Flex API and the FlexViewer are built around the ability to consume the REST EndPoint of ArcGIS Server.

So the query widget querys a MapService (through the REST EndPoint) that is published on ArcGIS Server.

Here is a link about publishing MXDs to ArcGIS Server.

http://help.arcgis.com/en/arcgisserver/10.0/help/arcgis_server_dotnet_help/index.html#/Tutorial_Publishing_a_map_service/00930000000p000000/

Re: What does the query widget query?

RichardHolloway — Fri, 10 Dec 2010 13:28:24 GMT

Yep, got that but in the query widget don't you have to set something on the layer of the webservice for it to query? Or am I not understanding it.

Re: What does the query widget query?

RichardHolloway — Fri, 10 Dec 2010 13:30:03 GMT

Is this what I need to look at? Geodatabase: Working with Standard Spatial Datasets

Re: What does the query widget query?

RobertScheitlin__GISP — Fri, 10 Dec 2010 13:30:37 GMT

Richard,

No you don't have to do anything if you except all the defaults and make sure that you don't have the shape or objectid fields of any layer in the mxd that you want to search.

Re: What does the query widget query?

RobertScheitlin__GISP — Fri, 10 Dec 2010 13:34:09 GMT

Richard,

Are you just trying to get your head wrapped around this or are you actually having issues querying one of your published map services?

Re: What does the query widget query?

RichardHolloway — Fri, 10 Dec 2010 13:37:53 GMT

LOL...getting my head wrapped around it. I am looking at the example in for the police depts on the query widget. I see the xml and all that but just don't see how to populate the items to be selected in the widget nor how does it select the items. What is it querying and how are the items set up to query in the layer. Does that make sense? All I see is the query in the xml and a result. No in between configuration.

Re: What does the query widget query?

RichardHolloway — Fri, 10 Dec 2010 13:40:00 GMT

Just found this link.
http://help.arcgis.com/en/webapi/flex/samples/index.html?sample=TimeSliderPlayFeature

Is this what I need to look at?

Re: What does the query widget query?

RobertScheitlin__GISP — Fri, 10 Dec 2010 13:43:19 GMT

Richard,

Maybe you should begin here with a simple sample of using the query task

http://help.arcgis.com/en/webapi/flex/samples/index.html?sample=QueryTaskOnMap

Re: What does the query widget query?

RobertScheitlin__GISP — Fri, 10 Dec 2010 13:46:37 GMT

Richard,

Also based on this statement

All I see is the query in the xml and a result. No in between configuration

it sounds like you are not using the FlexViewer source code. DO you have FlashBuilder?

Re: What does the query widget query?

RichardHolloway — Fri, 10 Dec 2010 13:48:05 GMT

Yep but I don't see the mxml just the .swf so your probably right. I did not think I need the source.

Re: What does the query widget query?

RichardHolloway — Fri, 10 Dec 2010 14:56:01 GMT

Ok so I am looking at the querywidget.mxml but don't see where its stating the webservice or setting the items that are contained within the widget.

Re: What does the query widget query?

RichardHolloway — Fri, 10 Dec 2010 14:57:27 GMT

Are those features in the layer as objects?

Re: What does the query widget query?

RobertScheitlin__GISP — Fri, 10 Dec 2010 15:17:56 GMT

Richard,

So in the QueryWidget.mxml Line 116

                    queryLayer = configXML.layer;

This is the line that sets a string variable to the mapservice url specified in the xml file. On line 254 that var is used to set the QueryTask. On line 286 the results from the QueryTask are recieved as a featureSet and sent to the createQueryResults function, where they are parsed and QueryResults.as values are set. The QueryResultsItemRenderer than uses those results to display them in the datagroup.

The FeatureSet is:

A set of features with information about their fields, field aliases, geometry type, spatial reference etc. The FeatureSet is returned by QueryTask.execute() and FeatureLayer.queryFeatures() and includes not only the graphics but also the metadata about them.

Re: What does the query widget query?

RichardHolloway — Fri, 10 Dec 2010 15:19:57 GMT

Ah...there it is. I was looking for something else. Cool.

Re: What does the query widget query?

RichardHolloway — Fri, 10 Dec 2010 19:22:34 GMT

Ok asked one of the arcmap guys for some help and got the attributes set up for a layer in my attributes table. So..for some reason on the query widget I get a invalid URL but the url is valid as a mapservice. Is that correct? I did notice on the service for the example it says feature layer. Does that matter?

Re: What does the query widget query?

RobertScheitlin__GISP — Fri, 10 Dec 2010 19:28:40 GMT

Richard,

When you are using query the specific layer of the map service has to be specified.

i.e http://yourserver/arcgis/rest/services/yourservice/2 meaning the 3rd layer of that map service will be queried.

Re: What does the query widget query?

RichardHolloway — Fri, 10 Dec 2010 19:37:12 GMT

That got it!! COOL! Thanks!!