19.14 Increment counter using appendfile()

Prerequisites

• Products: Liquid UI WS, Liquid UI Server or Local DLL, Client Software
• Commands: openfile(), appendfile(), closefile(), readfile()

Purpose

This article guides you through creating a file in SAP and incrementing the counter using the appendfile command. To demonstrate this with a scenario, we’ll guide you through the following steps.

1. Delete the image container on the SAP Easy Access screen
2. Add a push button to add content to a file
3. Add a function to append values to a file
4. Check the file for new content

User Interface

//Create this file inside your script folder for customizing the SAP Easy Access Screen, SAPLSMTR_NAVIGATION.E0100.sjs

//Now, let's add the Liquid UI script to the above file and save it.

Customization

1. Delete the image container on the SAP Easy Access screen using del().
    

   //Deletes the Image container on the screen
   del("X[IMAGE_CONTAINER]");

    
   
    
2. Add a toolbar push button Execute to initiate the testfunction process:
    

   // Creates a toolbar push button labeled Execute  
   pushbutton([TOOLBAR],'Execute','?',{'process':testFunction});
   

    
   
    
3. Add a function to declare a variable and invoke another function, passing the strFileName parameter.
    

   // Function to invoke another function
   function testFunction() {
       strFileName = 'counter.txt';
       appendToCounterFile(strFileName);
   }
   

    
4. Add a function to remove blank spaces.
    

   // Function to remove blank spaces
   String.prototype.trim = function() {
       return this.replace(/^\s+|\s+$/g,"");
   }
   

    
5. Add a function to validate blank spaces in the string.
    

   // Function to validate whether the variable holds a blank space or null value
   function isBlank(jvar){
       if(typeof jvar == undefined || jvar == null || jvar == "" || jvar == void 0)
           return true;
       else
           return jvar.toString().trim() == '';
   }
   

6. Add a function to create a text file named counter.txt, increment the counter value, and append it to the file.
    

   
   // Function that takes a file as a parameter and appends data to it
   function appendToCounterFile(fileName) {
   	var lastCounter = 0;
       var z_counter = '';
   	var strBlank = '';
       openfile(fileName,{"delimiter":","});
       NEXT_LINE_READ:;
       readfile(fileName,{"z_counter":true});
       if(isBlank(z_counter)) {
   		 goto END_OF_FILE;   
   		 }
   		 lastCounter = parseInt(z_counter);
   		 var z_counter = '';
   		 goto NEXT_LINE_READ;    
   		 END_OF_FILE:;   
   		 closefile(fileName);
   		 openfile(fileName,{"append":true, "delimiter":","});
   		 lastCounter++;    
   		 appendfile(fileName,{"lastCounter":true});
   		 closefile(fileName);
   		 }
   		 

    

SAP Process

1. Refresh the SAP Easy Access screen and click the Execute push button to increment the last value and append it to the file.