Dojo: The Definitive Guide

The APIs

This section provides a summary of the data APIs. If you're just getting started, you may want to skim this section to get a feel for the capabilities the APIs and then come back after you've read the rest of the chapter, which has more concrete examples, to explore it further.

The Read API

All data stores will implement the dojo.data.api.Read API because this API provides the means of retrieving, processing, and accessing the data—clearly a prerequisite for any other operation. The complete API specification follows in Table 9-1. The next section discusses a toolkit-provided implementation: ItemFileReadStore.

Tip

The API listings that follow use descriptors like dojo.data.api.Item to convey the notion of a dojo.data item even though an item is somewhat of an abstract concept.

Table 9-1. The dojo.data.api.Read API

Name	Comment
getValue(/*dojo.data.api.Item*/item, /*String*/attribute, /*Any?*/default)	Given an item and an attribute name, returns the value for the item. A value of undefined is returned if the attribute does not exist (whereas null is returned only if null is explicitly set as the value for the attribute). An optional parameter of default can be used to return a default value if one does not exist.
getValues(/*dojo.data.api.Item*/item, /*String*/attribute)	Works just like getValue except that it allows for multivalued attributes. Always returns an array regardless of the number of items returned. You should always use getValues for multivalued attributes.
getAttributes(/*dojo.data.api.Item*/item) ...