topic Re: Group layers and the Flex viewer in ArcGIS Viewer for Flex Questions

Group layers and the Flex viewer

RaymondBlack — Thu, 11 Nov 2010 07:33:45 GMT

Hi,
I have a map service with more than 30 layers grouped into several categories. Some of these groups also have sub-groups i.e. the hierarchy contains several levels. It appears that the Flex viewer does not honour the visibility settings of the parent (group) layer. For example if I have a group layer called Biodiversity and have several scale dependent children of this layer, whenever I zoom in, the child layers switch on automatically even if the parent (group) layer is switched off. It seems as if the flex viewer only looks at the visibility parameter of the individual layers - not at the visibility parameters of the entire hierarchy. This is completely counter-intuitive and indeed counter-productive since the viewer is spending inordinate amounts of time drawing layers that are not required. Needless to say it also generates a lot of confusion among users. Does anyone know how to correct this behaviour? I'm assuming it's a bug with the flex map component in that it doesn't traverse the layer tree to discover the visibility parameters of parent layers?

Note: All the grouping and default visibility in this example is set in the .mxd.

Thanks,

Raymond Black

Re: Group layers and the Flex viewer

RaymondBlack — Fri, 12 Nov 2010 10:08:34 GMT

Mea culpa,

It isn't the Flex Map that's causing the problem. It's the Layer List widget. Everything is fine until I select or deselect something on the widget. I guess it's when the widget rereads the list of visible layers that it switches everything on and ignores the group hierarchy.

Now that I know what it is, I'l have a go at fixing it! (Unless of course someone else already has a fix 😉 )

++ Ray

Re: Group layers and the Flex viewer

BjornSvensson — Fri, 12 Nov 2010 15:23:48 GMT

FYI - In Flex Viewer 2.1, as you've noticed, there are a few different issues with both default visibility for group layers and for turning on/off group layers. For version 2.2, we are planning to take advantage of a new legend component (and make sure that it works properly with group layers).

Re: Group layers and the Flex viewer

RaymondBlack — Mon, 15 Nov 2010 07:20:50 GMT

Thanks Bjorn,

I look forward to the update in version 2.2. The legend is another problem that I have on my to-do list, so the fact that the next release will address this too will be very helpful.

++ Ray

Re: Group layers and the Flex viewer

RaymondBlack — Wed, 22 Dec 2010 10:11:12 GMT

Hi Bjorn,

I agree with Andrea. This morning I tried the Flex 2.2 viewer (with Flex 2.2 API library) against an ArcGIS 10 map server with multiple group layers and there is no difference in operation between this version and the last one. If I switch on (or off) any of the group layers ALL the sub layers in other groups are drawn - even if their Group header is switched OFF.

Further, the legend widget doesn't work at all. I just get the icon that says it couldn't find any operational layers - despite the fact that the layerlist widget can find them with out any difficulty. Also if I close the legend widget, it cannot be opened again.

I checked the documentation to see if there was something I was missing in the configuration. If I am missing anything it's missing in the documentation also. Looks like we're using the release before test methodology.

++ Ray

Re: Group layers and the Flex viewer

MarkSmith1 — Thu, 23 Dec 2010 16:24:21 GMT

I'm just trying out the Legend widget for the first time today and I notice that unless the operational layer is a "feature" layer it isn't showing up in the legend. I have a couple of dynamic mapservices in my operational layer list and they have a single data frame with 3 - 4 layers in them.

Is this a bug or is it by design?

Re: Group layers and the Flex viewer

MehulChoksey — Thu, 23 Dec 2010 17:57:23 GMT

Here is more info on layers supported by legend widget and requirements for it:

http://help.arcgis.com/en/webapi/flex/apiref/index.html?com/esri/ags/components/Legend.html&com/esri/ags/components/class-list.html

especially note this excerpt from doc:
"If the layers are version 10 or lower the legend is created using the ArcGIS.com legend service. In order to use the ArcGIS.com legend service your map service needs to be publicly accessible and your application must be able to access ArcGIS.com."

and more info on legend widget is at http://help.arcgis.com/en/webapps/flexviewer/help/Default.htm#CSHID=widgets%2Flegend_widget.htm|StartTopic=widgets%2Flegend_widget.htm

Also note that by default the layers from the basemap are not used for displaying legend.You will need to set <usebasemaps> to true in config file of the legend widget. Hope this helps.

Re: Group layers and the Flex viewer

MarkSmith1 — Thu, 23 Dec 2010 18:51:21 GMT

Thanks. I applied Service Pack 1 and now the dynamic map layers are showing up.

Mark

Re: Group layers and the Flex viewer

RameshNarayan — Wed, 29 Dec 2010 04:59:06 GMT

Hi all,

I fixed the group layers toggle issue.
Added below if condition before "for loop" in "accumVisibleLayers()" funtion of "TocMapLayerItem.as". and it's working fine for me.

if(item.visible)
{
}
------------------------------------------------
file path : src\com.esri.viewer\components\toc\tocClasses\TocMapLayerItem.as
below is the modified function

private function accumVisibleLayers(item:TocItem, accum:Array, useLayerInfoName:Boolean = false):void
    {
        if (item.isGroupLayer())
        {
            // Don't include group layer IDs/names in the visible layer list, since the ArcGIS REST API
            // implicitly turns on all child layers when the group layer is visible. This goes
            // counter to what most users have come to expect from apps, e.g. ArcMap.

            //Added by Kiran to fix the group layers toggle issue
if(item.visible)
{
             for each (var child:TocItem in item.children)
             {
                 accumVisibleLayers(child, accum, useLayerInfoName);
             }
}
        }
        else
        { // Leaf layer
            if (item.visible)
            {
                if (item is TocLayerInfoItem)
                {
                    var layer:TocLayerInfoItem = TocLayerInfoItem(item);
                    accum.push(useLayerInfoName ? layer.layerInfo.name : layer.layerInfo.id);
                }
            }
        }
    }

---------------------------------------------------------------------

Thanks & Regards,
Kiran M

Re: Group layers and the Flex viewer

RobertScheitlin__GISP — Wed, 29 Dec 2010 12:04:25 GMT

Kiran,

Great Job! Finally with esri's changes in 2.2 and your code the TOC finally operates as expected.

Re: Group layers and the Flex viewer

DavidMarley — Wed, 05 Jan 2011 11:40:28 GMT

Kiran - Thanks for posting that fix. It worked for me as well - awesome!

One annoyance still with the layer list control and the "More..." section of the MapSwitcher is that they do not stay in synch. So if you change layer visibility in the layer list widget, the map updates correctly, but then if you go to "More..." that layer you just checked on (or off) is not set the same under there. I suppose the best approach here is to use one of the two controls, but not both.

Also, I can confirm that the legend widget was not working (was not showing any layers) until I upgraded my ArcGIS Server 10 server to SP1.

Regarding the legend widget, the point made by Mehul Choksey about the use of the ArcGIS.com legend service did not seem to work for me. My service is publically accessible - via a reverse proxy - and my app can access ArcGIS.com, at least as far as I know. What exactly is meant by "my app can access ArcGIS.com"? Is there any way to test/verify this? What is the URL for this legend service running on ArcGIS.com? Can I verify somehow that my app is accessing that?

Re: Group layers and the Flex viewer

DavidMarley — Wed, 05 Jan 2011 12:26:59 GMT

OK, found part of the answer regarding this ArcGIS.com legend service that's used for pre-10 SP1 services. Here is the URL:

http://orthogonal.esri.com/restlegends/

You can enter your URL on the page and then see the legend generated. You can also include the URL of your service in the URL to the ESRI service:
http://orthogonal.esri.com/restlegends/?soapUrl=http%3A%2F%2Fsampleserver1.arcgisonline.com%2FArcGIS%2Fservices%2FWaterTemplate%2FWaterDistributionInventoryReport%2FMapServer&f=html

Still not clear to me how or why this is not working in conjunction with the new legend widget in my case. (in other words, why my pre 10 SP1 service was not working in my app).

Re: Group layers and the Flex viewer

MehulChoksey — Wed, 05 Jan 2011 15:39:48 GMT

Could you capture HTTP request/response using firebug/httpfox or fiddler to see whats going on behind the scene?

Re: Group layers and the Flex viewer

DavidMarley — Mon, 17 Jan 2011 14:08:12 GMT

Thanks for checking in again Mehul. I have since tried the Legend Widget with a service running from a 9.3 SP1 server and it works fine. The day I was having problems it was with a version 10 (no SP) service - that was the one that did not seem to be getting the legend thumbnails from the ArcGIS.com legend service. Unfortunately now I have upgraded my AGS 10 test server to SP1 so I have no way to test/confirm. Maybe the problem that day was just an anomaly.

Re: Group layers and the Flex viewer

tongkimongki — Mon, 21 Mar 2011 10:21:24 GMT

Hi..

To masmisth (and everybody that knows).. u said "Thanks. I applied Service Pack 1 and now the dynamic map layers are showing up."..
which service pack di u refer to ? desktop ?arcgis server ?

thanks

Re: Group layers and the Flex viewer

DavidMarley — Mon, 21 Mar 2011 11:18:18 GMT

SP1 for ArcGIS Server 10.

Re: Group layers and the Flex viewer

EmilieLandois — Mon, 21 Mar 2011 15:29:37 GMT

Hello,

OK so concerning the legend widget problem there is the SP1

But, concerning the problem with the multiple group layers�?� and if I am using the flex Viewer compiled release�?� do you know an issue?

Thanks in adance

Re: Group layers and the Flex viewer

MarkSmith1 — Mon, 11 Apr 2011 13:08:48 GMT

Robert,

Have you incorporated Kiran's fix into your TOC widget by any chance?

Thanks,
Mark

Re: Group layers and the Flex viewer

DerekHunter — Thu, 28 Apr 2011 16:56:01 GMT

Has anyone seen their LayerList widget move inadvertently to the left whenever it is placed in the upper right area of the window? When I place it in any of the other 3 corners it stays put.