Page 222 - DCAP507_SYSTEM_SOFTWARE

System Software

Notes Toolbar
The toolbar shown in Figure 14.4 provides all the tools for drawing the query diagram. A node
is drawn by selecting the node tool and clicking on the graph panel.

Notes An edge is drawn by selecting the edge tool and clicking on a start node and an end node.

Figure 14.4: Toolbar

Select Tool: Used to select and move graph components in the draw panel for editing.
Document Node: Used to create document nodes which accesses XML files specified in filename
attribute and select elements using the pathname attribute to locate nodes.
Condition Node: Used to specify the general and value comparison operator through its condition
attribute. A condition Node is only valid when it is connected to at least two edges.
Element Node: Correspond to element nodes in XML file.
Return Node: Used to specify query output node. A return edge is only valid when it is connected
to a return edge.

Path Edge: Used to create a parent-child relationship between two nodes. The elements is selected
using the pathname attribute to locate nodes.
Value Edge: Valid only when connected to a condition node. Used to specify an absolute value
for comparison with element.
Return Edge: Valid only when connected to a return node and an element node. Select elements
using the pathname attribute to locate nodes for output.

XML Viewer

The XML Viewer shown in Figure 14.5 displays the hierarchy structure in a xml file. The user can
use the combo box to select file for viewing and only one file can be viewed at one time.

Figure 14.5: XML Viewer

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