Object Model

This section is targeted to explain the Plesk Sitebuilder domain model, namely, to show which managed objects exist in Sitebuilder and how they are related to each other.

Plesk Sitebuilder domain model objects are as follows:

• User. A Sitebuilder user account representing one of the 3 hierarchical system roles (Admin, Reseller, Site Owner) which define in what way a user is authorized to interact with the system. Aside from this hierarchy stands a Guest User - any unauthenticated system actor allowed to create trial sites. Each User is assigned to a particular plan (see the definition below), and each registered user can have Sites.
• Site. A system entity representing a particular set of web pages as a whole, identified by a unique identifier, owned by a User, and presumably filled with User's content. Site can also be defined as an instance of a particular page set employing some design template.
  
• Plan (Hosting Plan). A named set of of limits, permissions and available resources to which a user is assigned. A user assigned to a plan can operate the objects provided by the plan, and within the limitations defined by the plan, too. One user can be assigned to only plan, while one plan can have many users assigned to it. Plans are organized into a hierarchy according to the hierarchy of users.

  To understand the users and plans hierarchy, refer to the Figure 3.
  

• License. The system-level plan purchased from Parallels, the highest in the plans hierarchy.

• Resource. A Plan ingredient representing a system object available to a user according to a plan. Resources are Hosts, Design Templates, Site Families, Page Sets and Modules. To understand the user-determined relationship between plans and resources, refer to the Figure 4.Host. A physical or virtual operating environment which provides web hosting service for the users' sites. Host is identified by its name or IP address.
• Page Set. A named set of Web pages which represents web site structure and content template. It can be explained in other terms as site skeleton.
• Design Template. A template of web site design which could be applied to customize look and feel. Typically it has several color themes, header and menu variants.
• Module. An executable component which provides site dynamic content or extends web site functionality. Blog, forum, voting engine, and guestbook are examples of site modules that might be added to a site.
• Site Family. A resource which implies a predefined page set designed for the specific web site type, and exposes optional filter to the range of design templates suitable for this kind of web site.

The diagrams designed to illustrate the most important objects relationships in Plesk Sitebuilder use the following graphical conventions:

• 1...n means multiple relations or objects
• A B means "A owns B"
• A B means "A subordinates B", or "B obeys to A"
• A B means "B inherits from A"
• A B means "A utilizes B"

This diagram represents the hierarchical structure of users and plans in Sitebuilder.

Admin is a User automatically assigned to a General Plan - a License. Limited by the License, Admin creates his Sites and Plans, and assigns to these Plans another Users - Resellers and Site Owners. Both Resellers and Site Owners create their Sites according to the Plan to which each is assigned. Along with creating Sites, Reseller can also create his own Plans and Users, and assign these Users to his Plans. The Users that the Reseller creates are, again, Resellers and Site Owners who, again, create either their Sites and Plans (in case of a Reseller User), or their Sites only (in case of a Site Owner User). And the situation is repeated again and again, which results in creating multi-level hierarchy of Sitebuilder Plans and Users.

Plans are organized in such a hierarchy where, if moving top-down, the amount of Plan Resources is decreasing and increasing at the same time. The point is that Resellers do not create Plans by simply redistributing the parent Plan resources among them, some Resources (exactly, Hosts, Site Families, and Page Sets) can freely be created and used in addition to the inherited ones. This diagram illustrates how it happens:

When creating a Plan, Admin operates with the pool of Resources composed of the Resources provided (or restricted) by the License (Parent Plan Resources on the diagram) and the Resources that he created himself (Own Resources). A Reseller assigned to this Plan, in turn, can create Plans from the Parent Plan Resources adding to them his Own Resources. And so on.

The following diagram explains how a Reseller creates a Plan adding his Own Resources to the ones inherited from his Parent Plan, and how a Site created upon this Plan utilizes the resources:

Here, a Reseller (in fact, Admin is a Reseller, too, but of the highest level in the system) takes Design Templates, Hosts, Site Families, Page Sets and Modules provided by the Plan he is assigned to (Parent Plan Resources), adds to them Hosts, Site Families and Page Sets he created or somehow obtained (Admin/Reseller Resources), and creates his Own Plan from them. Then, a User assigned to this Plan can create a Site which will utilize all those resources the Reseller included to his Plan.