The XML DataSource Wizard properties are shown in Figure 7.2, “Define XML DataSource”.
The unique name of the data source is entered in the Name text box and any extra description that is used to describe the data source can be entered in the Description text box.
The format of date, time and timestamp strings in the XML can be specified. By default the date, time and timestamp formats follow ISO standards. If the date and time fields in the XML file follow a different format then that format has to be defined in the appropriate text boxes.
XML data can be supplied in one of two ways. You can either enter the URL of an XML file, or enter the XML directly into the wizard. The URL approach should be preferred when the XML contents is large. Where both URL and XML are specified, the XML value will take precedence.
Note
Both the URL and XML entries allow for ${substitution} to be used. For XML this allows the XML contents to be passed in through dynamic parameters - for example from a report. To do this, set the XML text to something like ${XML} and then supply the XML parameter at render time.
There are two ways by which the columns in the XML file can be added.
There is a main "Root XPath", which allows you to specify from which node in the tree you would want to start your traversal. The XPath is used to specify the XPath of the node, with respect to the "Root XPath".
Method 1
In this method the columns in the XML source can be added by clicking on the XPath Builder button shown in Figure 7.3, “Choosing the XPath Builder”.
There are two panel windows in the XPath Builder. The tree structure view of the XML file will be displayed in the left panel. The value of the fields selected in the XML file will be displayed in the text field below the panel.
The Root XPath is specified in the text box provided at the top of the right panel. Select the field to be displayed and then drag and drop them in the Field and XPath cells of the columns. Alternatively enter the name of the Field and XPath in the corresponding cells. Select the Merge type from the combo box. Then field values are displayed in the column.
On clicking the Ok button the selected fields are added to the Wizard.
Method 2
This method can be used if the XPath of the columns are already known. In this method the Root XPath is entered in the text box. There are five buttons. They are Add Column, Edit Column, Move Up, Move Down and Remove Column buttons.
On clicking the Add Column button, the Add Column dialog window appears. The name of the column is entered in the text box. The data type of the column is selected from the Data Type combo box.
The XPath is entered in the text box. Finally on selecting the Merge from the combo box and clicking the OK button the column is added to the Wizard.
The Edit Column button is used if the values in the column have to be altered. Using the Move Up and Move Down button the selected columns can be reordered if the sequence in which they are displayed needs to be changed. The Remove Column button is used to delete the column.