Transcript XML Data Islands - Engineering and Technology IUPUI
Embedding XML in HTML: Using Data Islands
Eugenia Fernandez IUPUI
Internet Explorer 5 Approach
• Treats XML as a Data Source Object or DSO, also referred to as a data island • Handles symmetric data best, i.e. data that resembles a relational table • Can use multiple data islands in same HTML file • Each data island requires unique ID
Defining a Data Island
• A data island is defined within the
– explicitly, by embedding XML data directly
some XML
– implicitly, by reference to external XML file
Mapping XML Data to an ADO Recordset
XML data within an XML data island is treated as an ADO recordset. Each main element maps to a record in the ADO recordset, and each child element maps to a field in the record.
ADO Mapping Example
Title
The Autobiography of Benjamin Franklin The Confidence Man
Author
Benjamin Franklin Herman Melville
Price
8.99
11.99
Binding Data Islands to HMTL Elements
• Individual fields can be bound to HTML tags using the DATASRC and DATAFLD attributes – DATASRC specifies the ID of the XML data island. The ID must be preceded with #.
– DATAFLD specifies the XML field from which data is taken.
HTML Elements That Support DSO Binding
• A • APPLET • BUTTON • DIV • FRAME • IFRAME • INPUT (where TYPE = CHECKBOX, HIDDEN, LABEL, PASSWORD, RADIO, TEXT) • IMG • LABEL • MARQUEE • SELECT • SPAN • TABLE • TEXTAREA
Displaying Data in HTML Tables
• Use a TABLE to display multiple rows of data.
• Set the DATASRC in the TABLE tag.
• For each TD, include an HTML element and set its DATAFLD attribute • The data binding agent automatically populates multiple rows, for each record in the XML dataset.
Paging the DSO Data
• For large XML data islands, DSO allows the data to be displayed in pages. • The size of the page is set through the DATAPAGESIZE attribute in the TABLE tag.
Accessing Repeating XML Elements • Use a nested table to access repeating XML elements
Accessing XML Attributes
• XML attributes are treated as child elements
Navigating the DSO Recordset
• You can navigate through your DSO Recordset by adding script to call the ADO move methods: – Move, MoveFirst, MoveLast, MoveNext, MovePrevious • Example
xmldso.recordset.MoveNext
Adding Navigation
• Add a field to display the data • Add a button to invoke the desired move method.
Adding Navigation, cont.
• Set an onclick event procedure for the button that calls the move command.
Sources
• “Building XML-Based Web Applications” a Microsoft Certified Course.
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