Prizm Application Services (PAS) is a new service that provides application-level logic for the viewer, such as enabling document viewing through the PCC back-end services, saving and loading of markup, and handling opening of documents and creating viewing sessions. This service is designed to be a gateway between the viewer and the Prizm back-end services, and takes the place of the Web Tier samples available in previous versions of the product. This new service is designed to lower the startup costs of integrating the PCC product and to allow easier upgrading of the product, while still maintaining the flexibility that the source-code Web Tier samples allowed.
This new service is intended to run in the place of the previous Web Tier samples, on the same server as your web tier, although that is not required. Since it is a standalone service, it can run anywhere between your web application and the PCC back-end, including on its own separate machine if necessary.
To understand the service better, it is beneficial to first look at the entire PCC architecture before the service:
Architecture before Prizm Application Services
In past releases, the PCC Web Tier samples served two distinct purposes:
- Served as a proxy into the back end PCC document conversion services
- Allowed access to resources, such as annotation files and image files
It required customers to integrate that logic into their own application, as illustrated by the chart below:
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This architecture raises issues with the startup cost of integrating complex code into an existing web application. These samples also raised the difficulty of upgrading to a new version of the product, as any updates to the samples would have to be introduced into the custom application, resolving all differences between the two implementations.
Architecture in PCC v10.5 using Prizm Application Services
PAS resolves those issues by providing the same logic as the previous Web Tier Samples in a stand-alone service. The only requirement that PAS has is that a single, configurable endpoint from the viewer is proxied to PAS. If logic beyond the default behavior is required, such as customized storage of markup for example, PAS exposes a flexible API allowing the user to handle only very specific viewer requests while delegating all others to PAS.
With the introduction of PAS, the Web Tier Samples in the PCC product only include a small amount of proxy code, which accomplishes the forwarding of viewer requests to PAS. This provides minimal code for customers to implement, and it is code that should not need updates often.
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In this new architecture, PAS handles the business logic of running the viewer, while providing a flexible API to allow handling only specific calls with custom application logic while letting the rest be handled by the service. Since this is a standalone HTTP service, it does not necessarily need to run on the same machine as the web tier anymore. It can also run alongside the PCC back-end services, or on its own separate machine.
The minimal code that comes with the Web Tier Samples is now truly a suggestion, as any proxy into PAS will accomplish the task. For a more performant solution, we would encourage you to handle proxying through your web server of choice (such as Apache, NginX, or IIS), allowing your web application to only contain your own logic, without the need to integrate any Accusoft sample code. This is outlined by the architecture below:
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Information on configuring PAS through your server’s entry point and handling specific routes using custom logic is available in the How-To section for Working with Prizm Application Services.