nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }

N00b question: How am I triggering a TypeError within the API?

DonRea

Raw beginner here, trying to figure this out. I am attempting to create a FeatureLayer object; at this point, simply creating it and adding it to a map object is all I'm shooting for. Here's my whole script:

<script type="text/javascript" src="http://serverapi.arcgisonline.com/jsapi/arcgis/?v=3.1"></script>

<script type="text/javascript">

dojo.require("esri.map");
dojo.require("esri.layers.FeatureLayer");

function init ( )
{
 var startExtent = new esri.geometry.Extent
 (
  -460735.08683161414 // bottom x
  ,109870.9884550733 // left y
  ,605952.1265091426 // top x
  ,521356.80020335224 // right y
  ,new esri.SpatialReference ({wkt : "GRS_1980"})
 );

 var map = new esri.Map ("map", {extent : startExtent, fitExtent : true});

 var features = new esri.layers.FeatureLayer
 (
  "http://gis-app.bucknell.edu:6080/arcgis/rest/services/Pilot_FeatureAccess/MapServer"
  ,{mode : esri.layers.FeatureLayer.MODE_SNAPSHOT, outFields : ["*"]}
 );
 map.addLayers ([features]);
}

dojo.addOnLoad (init);

</script>

When I load the page, the console is showing two TypeErrors being thrown within the API. I don't even know where to begin looking for the problem at my level of inexperience.

Vind meer berichten getagd met

Accepted answers

All comments

DonRea

Thanks for the information - all of it was useful - but this specific problem turned out to be my lack of understanding of the map services themselves. I was trying to load a raster layer into a esri.featureLayer, not knowing that there even was such a thing as a feature layer in a map.

__Rich_

When you reference a feature layer, you need to include the layer's ID on the end of the URL.

Just to add, the reason for this is given in the reference documentation:

The feature layer inherits from the graphics layer and can be used to display features from a single layer in either a Map Service or Feature Service.

Perhaps the documentation could be improved to be a little bit more explicit/obvious?

For example the definition of the url parameter passed to the constructor reads:

URL to the ArcGIS Server REST resource that represents a feature service

Perhaps that's a good place to state that it should be a URL to single layer within a service etc.

StephenLead

    var features = new esri.layers.FeatureLayer
    (
        "http://gis-app.bucknell.edu:6080/arcgis/rest/services/Pilot_FeatureAccess/MapServer"
        ,{mode : esri.layers.FeatureLayer.MODE_SNAPSHOT, outFields : ["*"]}
    );

When you reference a feature layer, you need to include the layer's ID on the end of the URL. See the Feature Layer sample, which lists the URL as:

var featureLayer = new esri.layers.FeatureLayer("http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/Hydrography/Watershed173811/MapServer/1"

note the "1" on the end.

Steve

DonRea

The TypeErrors are what I'm seeing in the console. Here's the page I'm testing with:
http://www-test-old.bucknell.edu/script/test/rea/map.html

derekswingley1

What do you see in the firebug console?

If you could post a complete, simple page that would be helpful.

DonRea

I see the dynamic layer okay, but I'm still getting the TypeErrors attributed to serverapi.arcgisonline.com:15. Looking at that file, it seems that all of the scripting is on line 15, so that doesn't really narrow it down much.

derekswingley1

This is helpful in explaining WKT: http://webhelp.esri.com/arcgisserver/9.3/java/index.htm#geodatabases/the_ogc-607957855.htm

What about my second bullet point? What happens when you add a dynamic map service layer to your map before attempting to add a feature layer?

DonRea

I got the spatial reference name, as well as the extent parameters, from the map information. I've tried several that all seem to be referred to there. Here's what I see:

PROJCS["Albers_PA",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Albers"],PARAMETER["Longitude_Of_Origin",-78.0],PARAMETER["Standard_Parallel_1",40.0],PARAMETER["Standard_Parallel_2",42.0],PARAMETER["Latitude_Of_Origin",39.0],UNIT["Meter",1.0]]

I honestly have no idea what any of that means or what I'm looking at. It looks like several nested spatial references to me, if I had to guess. Is there any doc that explains this stuff?

derekswingley1

Two things:
�??is that a valid wkt for a spatial reference? what spatial reference are you trying to use?
�??you have to add a dynamic or tiled map service to a map before you can add a feature layer

Doe mee aan het gesprek

Aangemelde leden kunnen berichten plaatsen, updates volgen en meer. Nieuw hier? Registreer een gratis account.

Snelle Links

Community Help
Find useful guides, FAQs, and documents to help you navigate and make the most of Esri Community.