FETCH Command for SQLcl

fetch.js

/* FETCH Command for SQLcl
 * FETCH is like EXEC but for functions instead of procedures.  
 * Usage:
 *   SQL> script fetch.js
 *   SQL> fetch SYS_CONTEXT('USERENV', 'CURRENT_SCHEMA')
 *     SYS_CONTEXT('USERENV','CURRENT_SCHEMA')                                                                                                                                                                                                                         
 *     ---------------------------------------
 *     CMU
 */

// see also:  https://github.com/oracle/oracle-db-tools/blob/master/sqlcl/SCRIPTING.md


function trimln(str)
{
    if(str[0] == "\n")
        return trimln(str.slice(1));
    if(str[str.length-1] == "\n")
        return trimln(str.slice(0, -1));
    else
        return str;
}


var command = {}; 

// Command handler
// @return true if the command was handled by this handler - otherwise false. 
command.handle = function (conn,ctx,cmd)
{
   var name = 'FETCH';
   var sql = cmd.getSql();  
   // Current Command begins with FETCH?
   if ( sql.toUpperCase().indexOf(name) == 0 ) 
   {
       sql = sql.slice(name.length());
       sql = trimln(sql);
       sql = "SELECT "+sql+" FROM dual;";

       sqlcl.setStmt(sql);  
       sqlcl.run();
       return true;
    }
   return false; 
}



// fired before ANY command
command.begin = function(conn,ctx,cmd) {
}

// fired after ANY Command
command.end = function(conn,ctx,cmd) {
}



// Extend the Java CommandListener
var CommandListener =  Java.type("oracle.dbtools.raptor.newscriptrunner.CommandListener");
var MyCmd = Java.extend(CommandListener, {
        handleEvent: command.handle ,
        beginEvent:  command.begin  ,
        endEvent:    command.end
});

// Add the new command to the Registry
var CommandRegistry = Java.type("oracle.dbtools.raptor.newscriptrunner.CommandRegistry");
CommandRegistry.addForAllStmtsListener(MyCmd.class);