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Accessing the Trap.NZ map feeds with ArcGIS

Accessing layers

  1. You can add a new WFS Server via Connections > Server > New WFS Server:image-1639599998857.png
  2. Enter the WFS URL in the format as described here
    https://io.trap.nz/geo/trapnz-projects/wfs/apikey/project_id
  3. The WFS server is set to return a maximum of 10k features per request. Therefore you must set a page size value smaller than that. We suggest 5k to begin with. Add a custom request parameter of PAGESIZE, with a value of 5000
  4. Leave the Authentication options blank (we are using the API key to control access)

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You will now see the available layers:
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Working with the layers

Right-click or drag the layer to the map to see the features.

Note that, by default, ArcGIS only shows a maximum of 3000 features in the WFS layer. To change this, right-click the layers, select properties and then set the maximum features to something well above what you expect should be returned.

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Filtering records

You can add a CQL filter to a WFS connection to filter features from the WSF server. This can be achieved by adding this parameter to the Custom request parameters - which can greatly reduce the amount of data retrieved (speeding up the transfer and improving performance).  

For example - if you are only interested in this year’s records, you could add a CQL filter as a Custom request parameter 

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Add cql_filter as Parameter, and record_date %3E '2021-01-01' as Value.

Note: symbols such as ‘<’ and ‘>’ need to be URL encoded, hence the %3E in place of >

 

 

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