Connector for SAP Commerce Cloud Manual / Version 2301
Table Of ContentsWhen the commerce system has to deliver the end user's web pages, CoreMedia Content Cloud offers a way to enrich those web pages with content from the CoreMedia CMS; the fragment connector.
Integrating content from the CoreMedia system into the shop pages presents a challenge due to the same-origin policy:
The image above shows a typical situation when a user requests a shop page that includes CoreMedia fragments.
The page request from the end user is sent to the commerce server.
While rendering the page, the commerce server requests a fragment from the CAE.
The returned fragment contains itself parts that must be delivered dynamically. Take the login button. It is user specific, hence it must not be cached. The CoreMedia Blueprint may include such parts via Ajax requests or as ESI tags, depending on the capabilities of the component which sent the request.
The commerce server returns the complete page, including the fragment that was rendered by the CAE.
Because it is assumed that the CoreMedia eCommerce fragment contains a dynamic part, which must not be cached, the browser tries to trigger an Ajax request to the CAE. But this breaks the same-origin policy and will not succeed.
Solution 1: Access-Control-Allow-Origin
The first solution is built into the CoreMedia Blueprint workspace, so you may use it out of the
box. The idea is to customize the same origin policy by setting the
Access-Control-Allow-Origin HTTP header accordingly. The allowed origins can be
configured via the properties cae.cors.allowed-origins-for-url-pattern[*].
cae.cors.allowed-origins-for-url-pattern[{path\:.*}]= \
http://my.site.domain1,https://my.site.domain2
To fine-tune the configuration for Cross-Origin Resource Sharing (CORS), use the provided
cae.cors configuration properties. See
Section 3.1.4, “CORS Properties” in Deployment Manual and
Section 4.3.1.8, “Solution for the Same-Origin Policy Problem” in Content Application Developer Manual.
Solution 2: The Proxy
To solve this problem the classical way, the Ajax request needs to be sent to the same origin than the whole page request in step 1 was. The next image shows the solution to this problem: A reverse proxy needs to be put in front of both the CAE and the commerce server.
Actually, you may use any proxy you feel comfortable with. The following snippet shows the
configuration for a Varnish. Two back ends were defined, one for the CoreMedia eCommerce CAE
named blueprint and another one for the commerce server named
commerce.
The vcl_recv subroutine is called for every request that reaches the Varnish
instance. Inside of it the request object req is examined that represents the
current request. If its url property starts with /blueprint/, it will
be sent to the CoreMedia eCommerce CAE. Any other request will be sent to the commerce system.
(~ means "contains" and the argument is a regular expression)
Now, if you request a shop URL through Varnish and the resulting page contains a CoreMedia eCommerce fragment including a dynamic part that must not be cached, like the sign in button, the Ajax request will work as expected.
backend commerce {
.host = "ham-its0484-v";
.port = "80";
}
backend blueprint {
.host = "ham-its0484";
.port = "40081";
}
sub vcl_recv {
if (req.url ~ "^/blueprint/") {
set req.backend = blueprint;
} else {
set req.backend = commerce;
}
}