Spry User Guide - Support - Adobe

The second script block links the SpryData.js Spry data library, which is stored in a folder called includes on the
server:
The Spry data library depends on the XPath library, so it’s important that you always link the XPath library first.
The third script block contains the statement that creates the dsSpecials data set. The cafetownsend.xml XML
source file is stored in a folder called data on the server:
var dsSpecials = new Spry.Data.XMLDataSet("data/cafetownsend.xml", "specials/menu_item");
Note: Remember that JavaScript and XML are case-sensitive languages, so it's important that you make sure that the
scripts and column names you specify are capitalized (or not capitalized) appropriately.
In JavaScript the new operator is used to create objects. The Spry.Data.XMLDataSet method is a constructor in the
Spry data library that creates new Spry data set objects. The constructor takes two parameters: the source of the data
("data/cafetownsend.xml", in this case, a relative URL) and an XPath expression that specifies the node or nodes
in the XML to supply the data ("specials/menu_item").
You can also specify an absolute URL as the source of the XML data, as follows:
var dsSpecials = new
Spry.Data.XMLDataSet("http://www.somesite.com/somefolder/cafetownsend.xml",
"specials/menu_item");
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Note: The URL you decide to use (whether absolute or relative) is subject to the browser’s security model, which means
that you can only load data from an XML source that is on the same server domain as the HTML page you’re linking
from. You can avoid this limitation by providing a cross-domain service script. For more information, consult your server
administrator.
In the preceding example, the constructor creates a new dsSpecials Spry data set object. The data set obtains data
from the specials/menu_item node (specified by XPath) in the cafetownsend.xml XML file and converts the data
to a flattened array of objects and properties, similar to the rows and columns of a table. (For an example of the table,
see the beginning of this section.)
Each data set maintains the notion of a current row.Bydefault,thecurrentrowissettothefirstrowinthedataset.
Later, you can change the current row programmatically by calling the setCurrentRow() method on the data set
object. For more information, see “Set or change current row” on page 124.
Note: The data set contains no data after you've created it with the new JavaScript operator. To load data into the
dataset, first call the data set's loadData() method, which executes a request to load the XML data. Spry regions and
detail regions do this automatically for the data sets they depend on, but if you are not using one of these regions, call
the loadData() method manually in your page code. This loading is asynchronous, so the data might still be
unavailable if you try to access it immediately after calling loadData().
Spry XML Data Set advanced examples
Spry XML data sets use the XMLHTTPRequest object to asynchronously load the specified URL. When the XML data
arrives, it is actually in two formats: a text format, and a document object model (DOM) tree format.
For example, say that you’ve specified “/photos.php?galleryid=2000” as your data source. (This is a path to a
web service that retrieves XML data).
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