MapThat – Missing Field in WMS

By David Crowther

Question:

Why is a field missing in the MapThat Bubble for one of my WMS Layers?

Answer:

MapThat will only render fields in Information Bubbles that have been successfully exposed via the WMS source.

If the layer comes from your own GeoServer instance then the first thing to check is whether the WMS shows those fields when you view it using the Layer Preview > OpenLayers.

Here we have the LSOA for Liverpool:

And when displayed in OpenLayers we can click on a map object to view the attributes.

MapThat will only be able to show Fields which are available/exposed via the WMS.

If a field is missing there may be two reasons:

1 – Has the data changed since the WMS was initially created? – by checking the WMS in the LAYER settings, you can scroll down to the bottom of the DATA tab and see the list of fields in the Feature Type Details section:

If there are missing fields, then choose the Reload feature type button and the source fields will be checked and updated. Any newly added fields will now be included in the published WMS and MapThat can use those to add the values into the Bubbles.

2 – If the source data for the WMS is in a database, by default the Primary Key field is not exposed. If the data that you wish to show is within the Primary Key field, then the MapThat Bubble wont be able to show the values as these are not being published.

In the DATA STORE page, choose your Store Name to edit/view the settings.

….. and check whether the tick box Expose Primary Key has been checked or not. If it hasn’t and the data you wish to show is in the Primary Key field, tick the box and Save the Data Store settings.

Now in MapThat your Information Bubble will show the values from the Primary Key field.