Customizing providers

Providers in the Kentico API are classes that allow the system to manipulate objects and perform various actions. The following list presents the providers that the system uses and their purpose:

• Info providers contain methods for working with specific types of objects stored in the database, such as users, contacts, custom table records, etc.
• Data provider handles low-level database operations. The Info providers are built on top of the Data provider and use it to store and fetch data.
• Email provider manages the email queue and sends emails.
• Search provider ensures the functionality of the SQL search.
• File system providers allow you to access various file systems. They extend the CMS.IO namespace. See Working with physical files using the API to learn how to write a custom file system provider.

By developing custom providers and using them instead of the standard ones, you can modify the behavior of the application (or a specific feature) according to your exact requirements.

Adding your custom code files

When developing custom functionality, you can place your code files in:

• The App_Code folder (orCMSApp_AppCode -> Old_App_Code if you use a web application project)
• A separate project (assembly) integrated into the main web project

Placing your customizations into the App_Code folder ensures that the code is compiled dynamically when required and automatically referenced in all other parts of the application.

Writing the custom code

Every class used to customize the application must inherit from the original class. This allows you to implement your modifications or additions by overriding the members of the given class. When creating overrides for existing methods, it is recommended to call the original base method within your custom code.

Registering custom providers

After you write the code, you must register your custom classes to ensure that the system uses them instead of the default providers. You can choose between two options of registering custom provider classes:

• Using assembly attributes - the most straightforward way to register providers.
• Using the web.config file - allows you to switch between different providers (custom or default) without having to edit the application code.

Other customization options

In addition to providers, you can also customize the following helper and manager classes:

You can also use  global event handlers to customize the behavior of the system. Handlers allow you to execute custom code whenever a specific event occurs in the system, such as page or object changes, various parts of the user authentication process, etc.

Examples

• Custom Info provider example demonstrates how to customize standard Info providers.
• Custom Email provider example shows a sample customization of the email provider. Uses the web.config extensibility section to register the custom provider.
• Custom Data provider example describes the specific steps that you need to take to customize the Data provider.
• Custom SQL search provider example demonstrates how you can modify the SQL search provider.