Pipelines
A pipeline is an extensible software framework that defines and links together one or more stages of a business process, running them in sequence to complete a specific task. For example, the Order Processing Pipeline provides the sequence of steps that are used to process purchases from your site. In the first stage in the Order Processing Pipeline, you retrieve the product information from the database that stores catalog data. In the next stage, you add the address of the user to the order. Each stage in the pipeline represents a category of work. The sequence of the stages determines the sequence in which the work is to be done.
Commerce Server 2000 includes a set of pipelines that perform much of the standard processing required by a Commerce Server site. A site developer can tailor these pipelines to meet the specific needs for the site. For example, a site developer can add new stages to the pipeline, integrate the pipeline components with your existing system, or replace the components with other components supplied by third parties.
Types of Pipelines
Pipeline Structure
Creating and Editing Pipelines
Types of Pipelines
Commerce Server includes the following types of pipelines:
Content Selection Pipeline. Selects content to be displayed to users. For example, it determines which advertisements a user should see or which discounts a user should receive, based on the targeting expressions you created using Commerce Server Business Desk, how many advertisements are to be delivered, and other factors.
Event Processing Pipeline. Records events related to the displayed content (for example, a user clicking on an ad) and stores it in the Commerce Server databases. This information is then used for reporting purposes, for example, how many users have clicked on an ad.
Direct Mailer Pipeline. Constructs and delivers messages for direct mail campaigns. It can construct personalized e-mail messages or messages with static content.
Order Processing Pipeline. Processes either business-to-consumer (retail) orders or business-to-business (supplier) orders. These pipelines ensure an order goes through all the necessary stages to be processed appropriately. For example, it retrieves the product description from the catalog, retrieves the shipping address for the user, computes the amount of tax, and computes the total price.
Commerce Server includes the following types of Order Processing Pipelines:
Product Pipeline. Computes price and discount information for a product.
Plan Pipeline. Verifies the integrity of the order. For example, if the order does not contain any items, then an error is generated.
Purchase Pipeline. Accepts the final purchase of an order form, writes an order to database storage and, optionally, finalizes a receipt and writes the contents of the order to the receipt database
Pipeline Structure
A pipeline is defined in a pipeline configuration file, which has a .pcf file extension. In the .pcf file, you can see the stages of the pipeline. Each stage contains one or more pipeline components. A site developer can configure each stage to work with the unique requirements of your site.
The following figure shows the stages of the Retailing Purchase Pipeline (the Purchase.pcf file).
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Information is passed from an ASP page to the pipeline using the following two dictionaries:
Context dictionary. A read-only dictionary that provides the pipeline with information about the environment. For example, it might contain the connection string for a database.
Order dictionary. A read-write dictionary that provides the data that the pipeline is to process. For example, when a user submits an order, all the information is gathered together in the order dictionary, and is then passed to the Order Processing Pipeline.
The content of each dictionary is dependent on the type of pipeline. A site developer specifies the information that must be included in the dictionary on the ASP page.
Commerce Server pipelines can be run as transactions, which allow the pipeline to roll back the process if an error occurs. In addition, Commerce Server pipelines take advantage of Microsoft Windows 2000 Server object pooling to greatly increase the processing speed. For information about object pooling, see the Windows 2000 Server online documentation.
Creating and Editing Pipelines
A site developer uses the Pipeline Editor to create new pipelines and to change existing pipelines. Commerce Server provides seven pre-configured pipeline templates that you can use as a basis for your own custom pipeline. The template files for creating new pipelines have the .pct (pipeline configuration template) file extension. You can change the names of stages and add or delete stages. You can add or delete any component in any stage. For more information, see "Working with Pipelines" in Commerce Server 2000 Help.