Programming Social Applications

Dynamic Parameters

Dynamic parameters refer to the ability to build a data request’s parameters based on the response structure of another request or on standard gadget view parameters or user preferences.

There are several cases where using dynamic parameters would be incredibly useful when you’re making requests for data from the container or from an external source:

• If you are using variables passed from the container or into the view to control the type of information to be obtained

• If there were custom user preferences set during the program flow that need to be used to capture particular information from the source

• If the information used in the attributes of one data pipe request (e.g., os:DataRequest()) should be based upon the result set of another, earlier data pipe request (e.g., os:PeopleRequest())

Dynamic parameters may be applied to a number of attributes within the data pipe tags. Creating a data pipe from a DataRequest call allows the developer to include dynamic parameters in any attribute of the tag, with the exceptions of key and method. Other than a DataRequest call, dynamic parameters may be included in a number of alternate attributes for other calls, as shown in Table 7-6.

Table 7-6. Dynamic parameter attributes

Attribute	Request types implementing
activityIds	os:ActivitiesRequest
count	os:PeopleRequest, os:ActivitiesRequest
fields	os:PeopleRequest, os:ViewerRequest, os:OwnerRequest, os:ActivitiesRequest
filterBy	os:PeopleRequest
filterOp	os:PeopleRequest
filterValue	os:PeopleRequest ...