SEO Module

The AWA.SEO module provides tools for search engine optimization when publishing pages that must be discovered and scanned by search engines. It provides sitemap generation and allows other modules to announce what they publish for search engines in the form of a sitemap entry.

A sitemap entry is described by the Sitemap_Entry type and it is composed of an absolute URI location, a last modification date, a priority, an optional image URI location and an optional image title. A module that wants to provide a list of sitemap entries must implement the Sitemap_Provider limited interface and implement the Create_Sitemap procedure. That procedure must populate a Sitemap_Info record which contains the sitemap entries that must be exposed. For example:

with AWA.SEO;
...
procedure Create_Sitemap (Provider : in Sitemap_Provider;
                          Sitemap  : in out Sitemap_Info) is
   Item : Sitempap_Entry;
begin
   ...
   Sitemap.Entries.Append (Item);
   ...
end Create_Sitemap;

The module that implements such sitemap provider must register itself to the SEO module by using the Register procedure and giving the name of the sitemap file:

AWA.SEO.Register ("my-sitemap.xml", My_Provider'Access);

Such registration should be made in the Configure procedure of the module.

Integration

To be able to use the SEO module, you will need to add the following line in your GNAT project file:

with "awa_seo";

The SEO_Module type manages the registration of sitemap providers, the registration of the sitmap servlet and the generation of sitemaps. Sitemap entries are cached globally by the module in a protected object. An instance of the SEO_Module must be declared and registered in the AWA application. The module instance can be defined as follows:

with AWA.SEO.Modules;
...
type Application is new AWA.Applications.Application with record
   SEO_Module : aliased AWA.SEO.Modules.SEO_Module;
end record;

And registered in the Initialize_Modules procedure by using:

Register (App    => App.Self.all'Access,
          Name   => AWA.SEO.Modules.NAME,
          URI    => "seo",
          Module => App.SEO_Module'Access);

the SEO_Module should be registered before a module that provides a sitemap provider.

Configuration

The SEO module defines the following configuration parameters:

Name	Description
seo.sitemap_prefix	The URL base prefix to be used for sitemap XML files.
	#{app_url_base}/sitemaps/
seo.sitemap_refresh	The cache delay in seconds before refreshing the sitemap and querying the sitemap provider.
	3600

SEO Servlet

The SEO_Servlet type is the servlet that generates the sitemap XML files by using the sitemap providers that have been registered in the SEO module. By default, the AWA.SEO module provides a configuration to register that servlet and expose the sitemap URIs but such configuration can be overriden. The default configuration is:

<servlet-mapping>
    <servlet-name>sitemaps</servlet-name>
    <url-pattern>/sitemaps/*</url-pattern>
</servlet-mapping>
<filter-mapping>
  <filter-name>service</filter-name>
  <url-pattern>/sitemaps/*</url-pattern>
</filter-mapping>