We have discussed in previous articles how to set up the network data
for pgrouting and how to develop a wrapper to search the route between two
points.
Here we will discuss how to set up Geoserver to provide the result of
the wrapper as a WMS or WFS layer to be used in a web page using OpenLayers 3
(next article) .Among all the Postgres / Postgis / Geoserver / OpenLayers
chain, this part is, still, the simplest. We simply have to set up a Workspace,
a Data Warehouse, and a layer using the wrapper SQL query developed in
the previous article.
Setting up a workspace
For the entire Geoserver setting up, you must log in as administrator to
the administration interface.
Once logged in, click Workspaces in the Data
module (left menu) and click Add New Workspace.
Fill in the two fields with a name for the workspace (here pgrouting)
and the domain address (http://pgrouting.org), then click the Send
button .
Setting up a data warehouse
Click Warehouses in the Data module on the left menu and
click Add New Warehouse.
On the list of Vector data sources, select PostGIS
The warehouse configuration page opens
In the workspaces list select the workspace that has just been created:
pgrouting, and give a name to your data source (here itineraries ).
Fill in the correct connection details for your Postgres database: the
database is the name of your Postgres database containing the network tables, a
username and login password. Avoid using the postgres username for obvious
security reasons. Create a username with rights only on the data necessary for
your application.
The rest of the information can be left the same.
Click the Save button . You will have the
configuration page of a new layer.
Click
on Configure a new SQL view
Assign a name to the display and enter the last sql query that we tested
in the previous article:
SELECT ST_MakeLine (route.geom) FROM (SELECT geom
FROM pgr_route_entreAetB (‘ways’,% x1%,% y1%,% x2%,% y2%) ORDER BY seq) AS
route
But at this stage you do not need to enter true coordinate values: we
replace them with variables. The values of these variables will be WMS or WFS
parameters that will be received.
In SQL View Settings, click Guess
Settings From SQL .
You must enter default values. They will be used in case of request
without coordinates.
Enter the following string ^ -? [\ d.] + $ in Regular
Validation Expression. The user will,only, be entitled to enter numbers in
the variables.
In Attributes , click Refresh .
Modify the geometry type to match the geometry returned by the sql query
(in this case a LineString) as well as the return SRID (here 4326).
Click Save .
It only remains to set up the rest of the parameters for the layer. In
our case it is enough to make sure that the native SRIDs and data are the needed
for our application.
For native SRID, as explained when setting up
the network tables, pgrouting works exclusively in 4326 (latitude / longitude).
On the other hand, in our WEB page (which we have not discussed yet) we will
use OpenStreetMap as a base map. Therefore, we need to set up the Geoserver
output in EPSG: 3857 (the SRID used by OSM).
Do not forget to change CRS management into a CRR re-projecter
from native to the CRS stated .
Click Emprises -> Based on Data and Calculated
on native emprises to complete the layer configuration.
Click Save .
Make sure you have everything set up by clicking
Layer Preview and selecting OpenLayers. You must get the route between the
points you entered as default points:
You have completed the Geoserver setting up.
