Step 5: Add the Apache Velocity Code

Add the Velocity Code for the Convert Character to Numeric Task

About the Apache Velocity Code

The CodeTemplate element contains the Apache Velocity code, which is used to generate the SAS code for the task. Apache Velocity code is a template engine based on Java. In the code, keywords that are identified with a dollar sign ($) are Velocity variables. Keywords with a number sign (#) are directives. For more information about this code, see Apache Velocity User’s Guide.

Until this point, you have focused on creating the user interface for the task. In your example task, the following code is in the CodeTemplate element by default:

<CodeTemplate>
<![CDATA[

   proc print=sashelp.cars;
   run;
]]>
</CodeTemplate>

If you ran the task (in other words, selected a variable to convert and clicked Run Icon

), you might have noticed that the contents of the Sashelp.Cars data set appeared on the RESULTS tab. The task ran successfully because the content in the CodeTemplate element is valid SAS code.

In this step, you replace the default Velocity code with the Velocity code for the Convert Character to Numeric task.

Add the Velocity Code for the Convert Character to Numeric Task

In the task definition, find the CodeTemplate element and remove the highlighted code:

<CodeTemplate>
<![CDATA[

   proc print=sashelp.cars;
   run;
]]>
</CodeTemplate>

Now, add the highlighted code to the CodeTemplate element:

<CodeTemplate>
   <![CDATA[

   #set($charvar=$invarname.get(0))

   #set($informat = "${informatType}${informatWidth}.")

  data $outputDSName;
  #if ($samename=='1')
      #set($newCol = "${charvar}_old")
      set $inlibname(rename=$charvar=$newCol);
      $charvar = input($newCol,$informat);
      drop $newCol;
  #else
      #set($newCol = "${charvar}_new")
      set $inlibname;
      $newCol = input($charvar,$informat);
   #end

   run;
   ]]>
</CodeTemplate>

Here is an explanation of this code:

1	$invarname is the Velocity variable for the role control. In this code, $charvar is set to the value of the invarname array. Because only one role is allowed, there can be only one item in the array, and you always fetch the role from the first location in the array.
2	$informatType is the Velocity variable that holds the return value for the option that you selected in the Category of informat option. $informatWidth is the contents of the Informat width option. In this line of code, you set a new Velocity variable `$informat` to be the concatenation of the `$informatType` variable, the `$informatWidth` variable, and a ‘.’ character. The period is required because all SAS informats end with a period.
3	This line is the beginning of the SAS code and is the first line in the DATA step. In this code, the $outputDSName Velocity variable represents the name of the output data set. The name of the output data set is determined by the value of the `outputDSName` option, which you defined in this code in the metadata: <Option name="outputDSName" inputType="outputdata" defaultValue="Test" required="true">Name of output data set:</Option> In the user interface, this text box is labeled Name of output data set.
4	If you want the name of the variable that you are converting to remain the same, you select the Same name? check box in the user interface. Selecting this check box sets the $samename Velocity variable to 1. When `$samename == 1`, these steps occur: In the #SET directive, the variable (represented by the $charvar Velocity variable) is renamed variable_old (represented by the $newCol Velocity variable). In the INPUT function in the SET statement, the $charvar Velocity variable is set to the value of the $newCol Velocity variable, which has been converted using the informat specified by the $informat Velocity variable. The value of the $informat Velocity variable is determined by the Category of informat and Informat width options in the user interface. In the DROP statement, the variable named variable_old is dropped from the output data set.
5	If you want to create a new variable, do not select the Same name? check box in the user interface. When the $samename Velocity variable is not equal to 1, these steps occur: In the #SET directive, the $newCol Velocity variable is created. $newCol is set to the name of the variable that you assigned to the Character variable to convert role (represented by $charvar) and appended by _new. For example, $newCol could be set to Date_new. The SET statement reads the input data set (represented by the $inlibname Velocity variable). In the INPUT statement, the new variable (represented by $newCol and called charvar_new) is set to the value of the variable that you assigned to the Character variable to convert role and the informat that you specified using the Category of informat and Informat width options.

Click

to save your CTM code.