KVanGraafeiland-esristaff

Make Useful Maps and Layers in ArcGIS

Blog Post created by KVanGraafeiland-esristaff Employee on May 3, 2019

Make Useful Maps and Layers Webinar

 

I recently co-hosted a webinar with Rich Nauman and Karisa Schroeder titled "Make Useful Maps and Layers in ArcGIS".  This webinar is a part of a larger Esri Spatial Data Webinar series, it lasted just under an hour and we covered topics such as how hosted feature layers and hosted vector tile layers can be used together in a web map.  Also discussed included collaboration groups and how they can be used within your organization to effectively leverage the diverse talents of your organization for publishing and managing content.  We showed a Python 3 script for updating/overwriting hosted feature services and how that can be used with a hosted feature view to store styling, attribute alias' and other settings.  A recording of the webinar is below followed by a series of related relevant topics and information from our Q&A.  

 

Make Useful Maps and Layers in ArcGIS | Esri Spatial Data Webinar - YouTube 

 

Q&A by Topic

Feature Update Script

Q: Where can I find the Overwrite Hosted Feature Services script?

A: The Overwrite Hosted Feature Services script is available on ArcGIS.com.

 

Q: Does the Python script update the hosted feature layer with data on disc?

A: Yes, you can use the script to update data from a local disc as well as URL.

 

Arcade

Q: What is Arcade?

A: Arcade is an expression language that can be used across the ArcGIS Platform. More Info. 

 

Q: Why not also add some fields that translate the codes into more useable text as well?

A: When I (Rich) was preparing the data for publication, I could have added one or more fields and then calculated them to provide more human readable values for some of the coded fields.

In this example, I used a second approach. I had a field that has a "T" or "F" value indicating if the feature is in a Special Flood Hazard Zone. I used an arcade expression to convert this value to the text "Special Flood Hazard Zone" when the value is "T" and when the value was "F" I left the new value as null. This way I can have "Special Flood Hazard Area" appear in my pop-up rather than a "T" or "F" and I still keep the field small with a length of 1 character instead of 25 characters if I had spelled the value out in a field. To see how this works search for USA Flood Hazard Areas feature layer in the Living Atlas. Open the layer in the online map viewer and then open the layer's table. If you scroll across the table all the way to the right you can see a field that is named "Special Flood Hazard Area". Note that the name of the field is in italics. This indicates that the field is being created on the fly by an Arcade expression. To see the Arcade expression, open the layer’s configure pop-up window and scroll down to Attribute Expressions. Highlight the expression and click the configure gear. This will open the Arcade editor and you can see the script.

 

Feature Layer Views

Q: Is it possible to save a feature service as a new layer and then change or edit the new layer?

A: Feature layer views provide multiple views of a layer and allow you to make changes to the layer. Edits to the view layer are reflected in the source feature layer.  This blog explains some of the details of how layer views can be used.

 

Q: Will edits to the layer view transfer to the parent feature service?

A: Yes - this blog provides a good example of how to use layer views that includes an editing workflow.

 

Q: Is there a way to reduce a data sets size? For instance, using the Flood Hazard Area map, but only around my county.

A: Yes, if you create a layer view and open it in the online map viewer you can click “More Options” next to the layer in the table of contents and select “Set View Definition” then “Define an Area of Interest” to limit your layer view to a specific area.

 

Q: Is Hosted Feature View available with Portal 10.6.1 ?

A: Yes, feature layer views are available in ArcGIS Enterprise 10.6 and 10.7.

 

Vector Tile Layers

Q: Why would I use a Vector Tile Layer instead of a Feature Layer?

A: Feature layers provide full access to feature attributes and geometry so that they can be used as an input to geoprocessing tools, models, and scripts.  Vector tile layers are useful for visualization especially at smaller scales. However, for analysis a feature layer is needed.

 

Q: Does creating vector tiles use AGOL credits?

A: Creating tiles in ArcGIS Pro does not consume credits. Hosting vector tiles in ArcGIS Online consumes 1.2 credits per 1 GB stored per month.

 

Q: Why did you choose feature layer and not the other choice?

A: Feature layers provide full access to feature attributes and geometry so that they can be used as an input to geoprocessing tools, models, and scripts.  Vector tile layers are useful for visualization especially at smaller scales. However, for analysis a feature layer is needed.

 

Q: What does cached scale actually do?

A: The cached scale refers to the range of scales that the tool will create vector tiles for. If the max setting was left at the default of 1:500 tiles would have been created for all scales up to 1:500. Since we only need tiles to draw in the web map at scales smaller than the feature layer can handle, we can save the processing time and make a much smaller tile package by setting the maximum scale to something like 1:288,000.

 

Q: Is Vector Tile Style Editor available for Portal users?

A: Not yet but look for it in a future release.  In portal you can make a copy of the vector tile layer and modify the style file to make changes to the symbology. 

 

Q: Can you use Vector Tile packaging tool for lines, such as water main or sanitary sewer layers?

A: Yes

 

Geojason

Q: How do you create the geojason from your own data?

A: The example in the demo was downloaded from a NOAA webpage. To create a geojason from your data you can use the feature to geojason tool.

 

Q: Why did you download the json file to your computer?

A: In this example I downloaded the data to my local computer so I could use the tool in ArcGIS Online to "Add an Item from my Computer" and create a hosted feature layer.

 

Q: Since you did download it, you have to run the python script to update it. Is that a correct understanding?

A: The Overwrite Hosted Feature Services script relies on an existing hosted feature layer in order to execute the overwrite/update.  As long as there is no schema change in the data there should be no issues updating.

 

Sharing subscription and premium layers in a webmap

Q: How can I share web Map which contain premium service with public?

A: If you want to share a map publicly that contains subscriber content or premium content, you can create a map-based app and configure it to allow access to the content through your organizational subscription. Your subscription will incur any credit costs.

 

Analysis

Q: I have a situation where our end user needs to extract data from a feature service so that he can run topology on those features and identify where edits need to happen. Is copying features from the feature service the best way to do this?

A: Yes.

 

Links

Publish hosted feature layers—ArcGIS Online Help | ArcGIS 

Create hosted feature layer views—ArcGIS Online Help | ArcGIS 

Create a collaboration—ArcGIS Online Help | ArcGIS 

Creating a Profile in Python

Python Script

Coral Hosted Feature View

Coral Dashboard

 

Also attached you should find a PDF copy of the PowerPoint Presentation used.

 

Thanks!

 

If you have any other questions please feel free to reach out:

Keith - KVanGraafeiland@esri.com

Rich - RNauman@esri.com

Karisa - KSchroeder@esri.com

 

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