How do I prevent duplicates, in XSL?

Question

How do I prevent duplicate entries into a list, and then ideally, sort that list? What I\'m doing, is when information at one level is missing, taking the information from

Answer 1

Try the following code:

  


  
    
  


  
    
      
        
          
          
            
            
            
            

              
              
              
              
                
                , 
                
              
            
            
          
        
      

      
      
        
      
    
  

It looks pretty much as the output you want:

  
      154, 156
      Clinic Building
      1947
   
  
      
         156
         3
      
  
  
      
         156
         Contact prints
      
  
  
      
         154
         Negatives
      
  

The trick is to use and distinct-values() together. See the (IMHO) great book from Michael Key "XSLT 2.0 and XPATH 2.0"