In this chapter, we looked into CMS page processing. Page processing in CMS is based on ASPX templates. It uses multiple layers, including IIS, ISAPI filters, the worker process, CMS Web application, Publishing API, CMS content server, and CMS database. The CMS Web application initializes and instantiates the CMS context, which provides access to the PAPI objects. The PAPI objects allow us to interact with the CMS database. The template ASPX file and the template metadata define how the placeholder server controls render the content. The content is obtained from and committed to the CMS database by the Placeholder object that corresponds to the placeholder server control. Depending on whether the page is requested in presentation mode or authoring mode, the placeholder server controls execute differently and emit different HTML in the resulting page.
Templates are central to the concepts and execution of CMS. In the next chapter, we will look into designing templates.