Basic setup of Drupal 7 + OpenLayers + Geofield + Views 3

Our goal

This configuration will setup Drupal 7 with our nodes plotted on an OpenLayers map, using Views module to gather and channel the information to the OpenLayers module. And Geofield letting you input geo data easily via the node add form. We'll also have the OpenLayers Cluster strategy implemented.

Intro

Drupal 7 has been out there for a while already, but not all modules have gotten around yet being compatible. While development on the needed modules for this setup is in beta and RC fases, the documentation is also ... in that fase or say ... not yet completely up to version.

After reading a lot of posts and some Drupal handbook pages on this subject, I noticed most of them are still aiming at D6. And a lot of questions about Drupal 7 versions are not really answered. So I've put together a small how-to combining notes from other posts and a bit of common sense and came to this configuration.

Let's get started!

Step 1: Install Drupal + the modules

Required modules:
Install Drupal 7 (used 7.12 at the time of writing)
Install Views3 (used views-7.x-3.3)
Install CTools (used ctools-7.x-1.0)
Install GeoField (used geofield-7.x-1.0)
Install OpenLayers (used openlayers-7.x-2.0-beta1)
Install Libraries (used libraries-7.x-1.0)
Install library geoPHP (used geoPHP version 0.8)
Download the geoPHP library from https://github.com/downloads/phayes/geoPHP/geoPHP.tar.gz
From the README:

Unarchive the library files and place in sites/all/libraries
Your directory structure should look like: /sites/all/libraries/geoPHP/geoPHP.inc

Optional:
Install Devel module (used devel-7.x-1.2.tar.gz) to generate a bunch of nodes to display on the map.

Quick install of Drupal 7 + the modules above using Drush:
In my setup the webroot directory is called 'oltest7'. So the first command would be run from /var/www for example.

Note: The setup of Drush is not part of this how-to.

drush dl drupal-7.x --drupal-project-rename=oltest7
cd oltest7
drush si minimal --db-url=mysql://root@localhost/oltest7_2
# newer Drush versions will print your User name and User password
 
# enable the field ui
drush en field_ui
 
# install view 3 + ctools
drush dl views-7.x
drush en view views_ui
# it will ask to donwload ctool because it views depends on ctools
# answer (y) to all
 
# install geofield + library
drush dl geofield-7.x
drush en geofield
# it will ask to download library module and enable it
# answer (y) to all
 
# install openlayers
# most stable at this point is beta 1
drush dl openlayers 7.x-2.0-beta1
drush en openlayers_views openlayers_ui openlayers
 
# optional: install devel for node creation
drush dl devel-7.x
drush en devel_generate devel
 
# install the geoPHP library
# from the web root directory
mkdir sites/all/libraries
cd sites/all/libraries
wget github.com/downloads/phayes/geoPHP/geoPHP.tar.gz --no-check-certificate
tar zxvf geoPHP.tar.gz

Step 2: Configure the OpenLayers module

Drush installed all modules in sites/all/modules/.
This shouldn't matter, but it's just here as a side note.

Step 2.1: Configure OpenLayers Geofield WIDGET map

We'll set a basic configuration for a map we use to enter the location data into Drupal.

# Go to 
admin/structure/openlayers/maps
# and 
clone the WIDGET map
Give the map title a name that makes sense to you, so you can recognize it later on.
# and
Save

Step 2.2: Configure OpenLayers Geofield FORMATTER map - part 1

This step is a lot like the config for the widget map, but this map will be used for output. The nodes will be plotted on this map.

Again, we'll set a basic configuration for a map we use to output the location data from Drupal.

# go to 
admin/structure/openlayers/maps
# and
clone the Geofield Formatter Map map
Give the map title a name that makes sence to you, so you can recognize it later on
# and
Save

You can configure the map later in the way you want the output to display your nodes.
We'll come back to this later to configure the Cluster strategy on the map.

Step 3: Configure a content type

We'll need a content type to enter nodes.
This content type will need a field to hold the geo data.

# go to
admin/structure/types

In the field configuation:

select the widget you configured in the previous step (2.1) for
"OpenLayers Map" setting.
# and
select "Store each simple feature as a separate field." from the Storage options

Step 4: Add some nodes

At this point it's practical to quickly add some nodes so you'll some data show up when you create the views.

Step 5: Configure Views

We use Views to scrape for nodes and send em of the to OpenLayers.
In Views we'll create two displays:

1. a page showing the maps,
2. an "OpenLayers Data Overlay"

Step 5.1: Add and configure a Views OpenLayers Data Overlay

Add the view

# go to 
admin/structure/views/add
# configure the view
show = content
type = Map item (or whatever ctype name you used)
# You don't have to create a page at this point yet.
Click "Continue and Edit"

Once you're in the view..
The Format show will be set to Fields and the Content: Title field will be added there by default.
We'all also need the geo information for the map. In view:

Add the "Content: Location" field
# Save it with the default settings

This display is were we actually scrap Drupal for the nodes to plot on the map!
After we add the OpenLayers Data Overlay display:

# At the top of the view 
click the "+ Add" 
# to add a views display and 
select "OpenLayers Data Overlay"

In the Format/Format section of the display:

select the "OpenLayers Data Overlay" radio
# next
In the "Map Data Sources" select box, select "WKT".
In the "WKT Field" select box, select "Content: Location".
In the "WKT Title" select box, select "Content: Title".

I only configured the title field, since it's all I want to show in the map popup balloon. If you want to show another node field, configure the Description field in the section above with node field you would like to see in there. You'll have to go back and add the field to the view before you can configure it in the OpenLayers Data Overlay settings.

At this point you should see some WKT appear in the Views preview for the nodes you have entered already.

Step 5.2: Add and configure a Views page

This is were we plot the scraped nodes from 2.3 on the map!
Note: You could do this in an entirely different view.

# at the top of the same view 
click the "+ Add" 
# to add a views display and 
select "Page"

In the Format/Format section

select the "OpenLayers Map" radio

In the Map select box,

select "YOUR CUSTOM FORMATTER MAP"

In the Page settings/Path section

type path where this page will be at. 
# I used "map", my page will be at http://localhost/map

Note: There won't be any nodes showing on the map just yet, since we haven't configured the map to show them ... yet!
We'll do this next... first: Save the view!

Step 6: Configure Geofield FORMATTER map - part 2

We want to the node to show up on the map. For this to happen we have to add the OpenLayers Overlay Data layer to the map.

# go back to 
admin/structure/openlayers/maps
# and 
edit the Geofield formatter map
go to vertical tab "Layers and styles" 
# and 
in the "overlay" table tick the checkboxes "Enabled" and "Activated" 
of your newly created OpenLayers Data Overlay
# and 
hit "Save"

If you go to the page you've just created. You should see a map with you nodes showing up.

Step 7: Cluster strategy (Optional)

Cluster Strategy let's you group the nodes to one point on the map for points that are close to each other. This functionality is in OpenLayers module already. We only have to enable it in the Formatter map.

So..

# go to
admin/structure/openlayers/maps 
# and 
edit your Geofield FORMATTER map
click the vertical tab "Behaviors"
tick the "Cluster Features"
tick the "<openlayers data overlay created by views>"
Distance = 20 # pixel distance on the map at the current zoom level
Threshold = 2 # minimal feature count within the "Distance"
Click "Save"

Go to the page you create to show the map and hit 'refresh'. Depending on the zoomlevel your map features / nodes will the clustered into 1 feature.

Note: If you used Devel module to generate nodes, then the Cluster strategy might show unexpected output when it comes to multipoint, polygon and line entries.

Step 8: Pop Up for Features (Optional)

The Pop Up for Features functionality provides a small balloon on the map when you click the feature. It's on the page and vertical tab as the Cluster Strategy functionality.

So..

# go to
admin/structure/openlayers/maps 
# and 
edit your Geofield FORMATTER map
click the vertical tab "Behaviors"
tick the "Pop Up for Features"
tick the "<openlayers data overlay created by views>"
Click "Save"

And that's it!
If you followed all the steps above you should now have a view showing a map using the OpenLayers module. Displaying your nodes with Cluster Strategy and Popup up balloons when you click on the feature in the map.

Comments? Suggestions?
I'll try adding some screenshots soon.

@todo: Add screenshots.