[GIS] Modify attributes of WFS layer in OpenLayers 3

openlayerswfs-t

I need to modofy attributes of features appeared on a map using OL3.
The features live in a postigs db and they are serverd through Geoserver.
What I want is to modify some of the non spatial attributes of each feature.

What I did in order to accomplish this is to create a menu in which the user selects the values he wants to modify for a specific feature and then save the changes with a button. On button click I would send an ajax request (jquery/php) in which I would update the table values based on the fid of the table.

If I understand correctly using WFS-T is a more appropriate way. Is that right? Can I change non spatial attribute values with WFS-T? If yes, is there an example using OL3?

Best Answer

Yes WFS-T is more appropriate and can be used to edit non spatial attributes as well. Look at: http://openlayers.org/en/v3.14.2/apidoc/ol.format.WFS.html#writeTransaction on how to generate the payload.

Related Solutions

GeoServer Web Mapping – The Role of WFS-T in a Web App

According to Wikipedia:

The WFS specification defines interfaces for describing data manipulation operations of geographic features. Data manipulation operations include the ability to:

get or query features based on spatial and non-spatial constraints

create a new feature instance

delete a feature instance

update a feature instance

You do not use it to store the data. It is not a database. You might want to consider PostGIS though. It is a spatial extension to Postgresql. That way, you can store spatial and non-spatial data in one place.

You might want to follow a setup like the one below:

enter image description here

Clarification: OpenLayers does not communicate directly with the database. It communicates with the middleware or map server using WFS-T. When you send a request to update the data on your OpenLayers client, the WFS-T request gets sent to the middleware which communicates with the database. The WFS-T request is then translated into an SQL query or whatever it is that's required to complete the operation.

What data should be updated using WFS-T? Is it just the pure geometry (shapes of "school districts") or also data directly associated with the geometries ("school district's number of students -property)? Or can we use WFS-T for all updates, also non-spatial data ("teacher" data - although this does not sound nice)

You can edit the geometries and the associated data using WFS-T. As for the nonspatial data without associated geometries, I think it's best to use other methods for that. Handle them like you would on a normal web app.

If the stored geometries are simple (points in the map, or rectangular areas), is it smart to involve WFS-T and it's added complexity, or would it be sensible alternative to persist those geometries using the right side of the diagram? You would just have simple X1,Y1,X2,Y2 fields in a non-spatial table "school district", and handle storing that data in your regular web application just like you store all other data.

As for the points, that would depend on what your app does. If it's primarily for visualization then I guess it's okay to just store them as x,y pairs. if you would like to do spatial analysis however, like queries, buffers etc then it would be preferable to store them on a spatial database and use a map server and WFS-T.

OpenLayers and WFS-T – Setting Attributes for Vectors

Simply add the attribute to the feature before the wfs-commit:

// feat is the feature with the area the user drawn
feat.attributes.INVADED_BY_ARMY_ID = 42;

Of course, you should save somewhere the army id...

Best Answer

Related Solutions

GeoServer Web Mapping – The Role of WFS-T in a Web App

OpenLayers and WFS-T – Setting Attributes for Vectors

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