Справочник Пользователя для TANDBERG D13639

TANDBERG MPS API 

User Guide 

 

5 

 

 
XPath is a comprehensive language to address data in XML documents. 
It is though very simple to understand the basics. If you are able to specify the path to a file 
on your computer, you are able to specify the path to an element in a XML structure. 
 
 
Example 1.5               
 
Let us go back to the serial port configurations of Example 1.1. 
 
<Configuration> 
  <SerialPort item="1"> 
    <BaudRate item="1">9600</BaudRate>  
    <Parity item="1">None</Parity>  
    <DataBits item="1">8</DataBits>  
    <StopBits item="1">1</StopBits>  
    <Mode item="1">Control</Mode>  
  </SerialPort> 
</Configuration> 
 
 
To specify the path to the SerialPort element we simply start at the root level and separate 
the levels in the tree structure by a slash (“/”): 
Configuration/SerialPort 
 
The path to the BaudRate element is: 
Configuration/SerialPort/BaudRate 
 
 
 
Example 1.6    
            
To address a specific item of an element, the item number is added within brackets (“[]”) after 
the element name. 
The path to the BaudRate element of SerialPort item 2 in Example 1.4 is: 
Configuration/SerialPort[2]/BaudRate 
If the item number is omitted for an element, all items of this element will be addressed. The 
following expression addresses the BaudRate element of both serial ports: 
Configuration/SerialPort/BaudRate 
 
 
Example 1.7      
          
When using XPath it is possible to omit specifying intermediate levels in the address 
expression. By using the powerful “double slash” you can address elements without having to 
specify the complete path. 
The expression below addresses the BaudRate element of both serial ports of Example 1.4: 
Configuration//BaudRate