Programming Social Applications

Working with Pipelined Data on the Client

There are several methods for working with pipelined data within the defined gadget. One method is defining a template to render the content of a data pipe, which we will discuss later in this chapter. Another method is to use the JavaScript APIs defined for working with data pipes.

The data sources for a gadget are stored within the gadget context, which we can obtain using a simple method call:

opensocial.data.getContext();

Using this as our base data, we can call methods to get data, set data, and build data change listeners around the data sources. We’ll go over these actions next.

Getting data objects

Note

The full code for this sample is available at https://github.com/jcleblanc/programming-social-applications/blob/master/chapter_7/pipeline_get_data.xml.

Now that you understand the gadget context concept, we can use a series of methods to manipulate the data sources. To start, you can easily set up the method for obtaining an object from a data pipe, getDataSet(), using the following format:

opensocial.data.getContext().getDataSet(key);

There is one parameter that is passed in to the getDataSet() method:

key (string)

The data pipe key where the new object should be inserted

Let’s assume that the gadget we are building will capture a small set of fields from the current application viewer as well as the same set of fields from the viewer’s friends. Our first task is to set up the data pipelining request to load the data sources:

<script type="text/os-data" ...