I'm creating a web map using Leaflet, and I want to be able to grab feature layers from our ArcServer. I have successfully been able to retrieve a feature class as JSON, but Esri's JSON objects don't follow the GeoJSON standards so they cannot be displayed.
Does anyone know of a conversion script or tool that handles this?
If not, I plan on creating a script to convert ArcServer JSON objects to GeoJSON.
OGR:
ogr2ogr -f GeoJSON test.json "http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/Hydrography/Watershed173811/FeatureServer/0/query?where=objectid+%3D+objectid&outfields=*&f=json" OGRGeoJSON
That command will read the query result directly from the URL. You can also supply it with a text file containing your JSON or you can directly supply encoded JSON on the command line. You can of course use ORG Python bindings to automate it within a script if necessary, or the library to do it in code.
For those that like web services, see Ogre an ogr2ogr web client which can convert json to geojson to and back, as well as geojson to shapefile.
Reference: http://www.gdal.org/drv_geojson.html
You can also see Esri's geojson-utils on Github that "contains [javascript] utilities for converting GeoJSON to other geographic json formats and vice versa. Currently only GeoJSON to Esri JSON has been developed. Also, note that only geometries in the WGS84 coordinate system are supported."
geojson-utils is deprecated. See arcgis-to-geojson-utils or terraformer
Now ArcGIS Server (since 10.4) and ArcGIS Online has GeoJSON through ArcGIS Rest API URL. All you need to do is set f=geojson in the URL and configure the service. Be aware, by default, ArcGIS Online will not allow GeoJSON export until you explicit permit other output formats.
Here is how to enable the export:
Export Data
Allow others to export to different formats. 5. Save and wait a few minutes.
In the query page, you should see the output format dropdown list with the GeoJSON option. The old was called json.
ESRI JSON to GeoJSON (for OpenLayers) *Likely to be modified for Leaflet javascript
//create esri JSON object
var myReturn = "esriObj = "+xmlHttpGet(restCall, false);
eval(myReturn);
I can now work with esriObj as a JSON object i.e. esriObj.geometryType. What happens in the xmlHttpGet method? Basically I create a XMLHttpRequest and pass in my REST URL – your can see this code here
3. OK i have my ‘ESRI query’ JSON object now I need to parse the features in this object and essentially create GeoJSON strings which the OpenLayers sample will be happy with – cue the code butchery…
function esriDeserialize(geojson)
{
var element = document.getElementById('text');
var type = document.getElementById("formatType").value;
var features = formats['in'][type].read(geojson);
var bounds;
if(features)
{
if(features.constructor != Array) {
features = [features];
}
for(var i=0; i<features.length;>
if (!bounds) {
bounds = features[i].geometry.getBounds();
} else {
bounds.extend(features[i].geometry.getBounds());
}
}
vectors.addFeatures(features);
//map.zoomToExtent(bounds);
var plural = (features.length > 1) ? 's' : '';
//element.value = features.length + ' feature' + plural + ' added'
} else {
element.value = 'Bad input ' + type;
}
}
function getEsriGeom(restCall){
//call ESRI Rest API
//"http://pc302926/ArcGIS/rest/services/worldadmin/MapServer/0/query?text=&geometry=&geometryType=esriGeometryEnvelope&inSR=&spatialRel=esriSpatialRelIntersects&where=%22FIPS_CNTRY%22+%3D+%27AS%27&returnGeometry=true&outSR=4326&outFields=&f=json"
var element = document.getElementById('text');
//create esri JSON object
var myReturn = "esriObj = "+xmlHttpGet(restCall, false);
eval(myReturn);
element.value = "";
var coordPairsPerFeature = 0;
//for each feature
for (var i=0; i < esriObj.features.length; i++)
{
//get the geometry
var o = esriObj.features[i].geometry;
element.value = element.value + esriObj.features[i].attributes.ADMIN_NAME;
//loop through all the rings
for (var s=0; s < o.rings.length; s++)
{
//create geojson start & end - i know i'm getting polygons
var geojsonstart = '{"type":"Feature", "id":"OpenLayers.Feature.Vector_124", "properties":{}, "geometry":{"type":"Polygon", "coordinates":[['
var geojsonend = ']]}, "crs":{"type":"OGC", "properties":{"urn":"urn:ogc:def:crs:OGC:1.3:CRS84"}}}';
//the coordinates for this ring
var coords = o.rings[s];
//loop through each coordinate
var coordPair="";
for (var g=0; g < coords.length; g++)
{
coordPairsPerFeature = coordPairsPerFeature+1;
//alert(coords[g]);
if(g==coords.length-1){
coordPair = coordPair+"["+coords[g]+"]";
}else{
coordPair=coordPair+"["+coords[g]+"],";
}
}
//combine to create geojson string
esriDeserialize(geojsonstart+coordPair+geojsonend);
}
element.value = element.value + "," + coordPairsPerFeature +"n";
}
}
</features.length;>
source: http://mapbutcher.com/blog/?p=62
Converting ArcGIS JSON to GeoJSONThere in pure Browser
there are 2 ways you can do
Note: use in node.js and use in browser are different, details see link
2) Esri/arcgis-to-geojson-utils
use in browser, ArcgisToGeojsonUtils is global var reference the entry point of this module
<script src="https://unpkg.com/@esri/[email protected]/dist/arcgis-to-geojson.js"></script>
// parse ArcGIS JSON, convert it to GeoJSON
const geojson = ArcgisToGeojsonUtils.arcgisToGeoJSON({
"x":-122.6764,
"y":45.5165,
"spatialReference": {
"wkid": 4326
}
});
However, if you want to bundle by yourself, just for learning, follow steps
a) You need to compile all the module source file into a single bundle.js
rollup.js install by
npm install --global rollup
then go to your js lib root folder, find the entry point js file, in this case it is index.js
$ rollup index.js --format umd --name "esri_arcgis_to_geojson" --file bundle.js
You should find a new file bundle.js in your root directory.
Now in your browser html file, include this bundle.js file
<script src='.../.../.../bundle.js'>
You can use it now by
// parse ArcGIS JSON, convert it to GeoJSON
var geojson = esri_arcgis_to_geojson.arcgisToGeoJSON({
"x":-122.6764,
"y":45.5165,
"spatialReference": {
"wkid": 4326
}
});
// take GeoJSON and convert it to ArcGIS JSON
var arcgis = esri_arcgis_to_geojson.geojsonToArcGIS({
"type": "Point",
"coordinates": [45.5165, -122.6764]
});enter code here
Remember esri_arcgis_to_geojson is the name you named the lib
This becomes the global variable name, available in browser.
The trick is, bundle process add instant implement function like (function xx {}) here is the top part from bundle.js
(function (global, factory) {
typeof exports === 'object' && typeof module !== 'undefined' ?
factory(exports) :
typeof define === 'function' && define.amd ? define(['exports'],
factory) :
(factory((global.arcgis_to_geojson = {})));
}(this, (function (exports) { 'use strict';
***ORIGINAL SOURCE CODE OF JS MODULE***
})));
Leaflet and ArGIS vector layer.
https://github.com/JasonSanford/leaflet-vector-layers
Working demo. http://geojason.info/leaflet-vector-layers/demos/arcgis-server/
More on Leaflet and ArcGIS.
You can get this fork which has support for ArcGIS server.
https://github.com/dtsagile/Leaflet/
var sitesLayer = new L.AgsDynamicLayer(
'http://ags2.dtsagile.com/ArcGIS/rest/services/LiveFeeds/WxMappr/MapServer',
{ maxZoom: 19,
attribution: "NOAA",
opacity: 1,
layers: 'show:2' });
_map.addLayer(sitesLayer);
http://blog.davebouwman.com/2011/08/04/leaflet-lean-mean-javascript-maps/
ArcGIS Image Services and Leaflet http://blog.geomusings.com/2012/04/17/arcgis-image-services-and-leaflet/
Its usually* pretty easy converting.
I made a script https://github.com/calvinmetcalf/esri2geo and there are others that work well too.
*The exception is multi-part polygons with holes which don't convert 1-to-1 without some geoprocessing.
I've built a server object extension to generate GeoJSON from ArcGIS Server map services. It's been tested with 10.1 and 10.2 but not earlier. https://github.com/geobabbler/AGSOpenFormats
For a one-time conversion I would have used the accepted answer from @Sasa Ivetic but needed something real-time, and Terraformer worked decently for that. Unfortunately it's only for single features by default, so for multiple features you need to loop through the array and add an ID to each feature:
var FeatureCollection = {
type: "FeatureCollection",
features: []
}
for (var i = 0; i < arcgis.features.length; i++) {
var feature = Terraformer.ArcGIS.parse(arcgis.features[i]);
feature.id = i;
FeatureCollection.features.push(feature)
};
This worked fine for me except on multi-part polygons (i.e. Alaska and its islands), but I'm new to this so it's possible I coded something incorrectly!
If its a one time query and you don't have more than 1000 features try pasting this into qgis by using the add vector layer - choose protocol and replace this arcgis rest URL with yours: http://geodata.epa.gov/arcgis/rest/services/OAR/USEPA_NEI_2005/MapServer/1/query?where=objectid+%3D+objectid&outfields=*&f=json ... This assumes you have gdal 1.10 installed
I made a web version of ESRI's Terraformer tool for ESRI JSON -> GeoJSON conversion in the browser at https://observablehq.com/@thadk/arcgis-json-parser-to-geojson which can be customized as needed when the ArcGIS server does not allow you to export it as GeoJSON directly.
Perhaps even easier you can use the Esri-leaflet library to add it natively as a layer in Leaflet.
If all you need is to return the ArcServer Service as a GeoJSON to use in whichever mapping tech you want, I highly recommend you look at this GitHub issue dialogue.
I am not going to replicate the dialogue here because that would waste time. Your options are clearly laid out there directly from Esri.
arcgis server rest api, feature service,
if you query the layer, with URL like this, .../FeatureServer/query?layerDefs=...
http://services3.arcgis.com/your_token/arcgis/rest/services/Parcels/FeatureServer/query?layerDefs={"0":""}&returnGeometry=true&f=pgeojson&geometryType=esriGeometryEnvelope&geometry={"xmin" : -117.923158, "ymin" : 33.644081, "xmax" : -117.921436, "ymax" : 33.645157,"spatialReference" : {"wkid" : 4326}}
You can not set geojson format, f=pgeojson will be bad request, f=json, because the return stuff is not feature, the layers json was return.
Try this html query page, you can see, no geojson option,
http://services3.arcgis.com/you_token/arcgis/rest/services/Parcels/FeatureServer/query
If you want to return geojson (feature), you must use this URL .../FeatureServer/0/query...
/0/ means layerID, if on has only 1 layer, then layerID = 0.....
Try this html query page, you can see, geojson is option, because you are query specific layer with layerID = 0
http://services3.arcgis.com/your_token/arcgis/rest/services/Parcels/FeatureServer/0/query
Note: remember to set those 2 parameters: outSR=4326&f=geojson in the URL spatial reference ID, srid = 4326, because web map all use this, f means format, both f=pgeojson and f=geojson works. If you don't set outSR=4326, arcgis server rest api by default will NOT use 4326, instead use something else, only 4326 has unit degree, which is used in most web map. Other format would not work with web maps.
By the way, for those want to use arcgis server rest api with tile service,
tilestream and others
/zoom(z)/x/y.png
http://localhost/v2/city_parcels/12/706/1641.png
arcgis server tile service: no png, x and y in different order
/zoom(z)/y/x
http://services3.arcgis.com/your_token/ArcGIS/rest/services/Parcels/MapServer/tile/12/1641/706