Editing EGL (programming language) (section)

== Code examples ==

=== Program ===
An EGL Program part is a generatable logic part with one entry point. Each Program part contains a main() function, which represents the logic that runs at program start up. A program can include other functions and can access functions that are outside of the program. The function main() can invoke those other functions. Program functions are composed of a set of EGL statements, variables, and constants.

<syntaxhighlight lang="pascal" line highlight="5">
Program HelloWorld

	const GREETING string = "Hello, ";
    
	function main()
		myName string = "John";
		sayHello(myName);
	end

	function sayHello(name String in)
		SysLib.writeStdOut(GREETING + name + "!");
	end

end
</syntaxhighlight>

=== Record ===
An EGL Record part defines a set of data elements. In this example, a record with the name '''''CustomerRecord''''' is defined with 6 fields.

<syntaxhighlight lang="pascal">
Record CustomerRecord type BasicRecord
	customerNumber INT;            
	customerName STRING;
	customerAddr1 STRING;
	customerAddr2 STRING;
	customerAddr3 STRING;
	customerBalance MONEY;
end
</syntaxhighlight>

EGL has a specialized type of record called '''''SQLRecord''''' that is used to exchange data with a relational database.

<syntaxhighlight lang="text">
record Employee type sqlRecord { tableNames =[["Employee"]], keyItems =[EMPNO]}
    EMPNUMBER string{ column = "EMPNO", maxLen = 6};
    FIRSTNME string{ sqlVariableLen = yes, maxLen = 12};
    MIDINIT string{ isSqlNullable = yes, maxLen = 1};
    LASTNAME string{ sqlVariableLen = yes, maxLen = 15};
    DEPT string{ column = "WORKDEPT", isSqlNullable = yes, maxLen = 3};
    PHONENO string{ isSqlNullable = yes, maxLen = 4};
    HIREDATE date{ isSqlNullable = yes};
end

</syntaxhighlight>

* In this example, the record '''''Employee''''' is bound to a table (or view) named '''''Employee'''''.

=== Service ===
An EGL Service part contains public functions meant to be accessed from other applications or systems. In this example, a service with two functions is defined.

<syntaxhighlight lang="pascal" line highlight="1,5,11">
package com.mycompany.services;

service EmployeeService

    function getEmployees() returns(Employee[])
        records Employee[0]; // define an empty array of records
        get records; // retrieve records from the database
        return (records); // return the records       
    end
    
    function addEmployee(emp Employee in) returns (boolean)
    	try
    		add remp;
    		return (true);
    	onException (ex AnyException)
    		return (false);
    	end
    end

end
</syntaxhighlight>

* In EGL, code is organized in packages (like [[Java (programming language)]])
* The first function, ''getEmployees'', returns an array of records populated from the records in a database.
* The second function, ''addEmployee'' adds a new record to the database and returns a true or false depending on whether the record was added successfully.

=== RUIHandler ===
The main component of a Rich UI application is a Rich UI handler part. These parts are generated into JavaScript.

<syntaxhighlight lang="javascript" line highlight="8">
package com.mycompany.ui;

import com.mycompany.services.Employee;
import com.mycompany.services.EmployeeService;
import dojo.widgets.DojoGrid;
import dojo.widgets.DojoGridColumn;

handler EmployeeView type RUIhandler { initialUI = [ grid ], 
                                       onConstructionFunction = start, 
                                       cssFile = "main.css" }

    grid DojoGrid { behaviors = [ ], headerBehaviors = [ ], columns = [
                    new DojoGridColumn { displayName = "First Name", name = "FIRSTNAME" },
                    new DojoGridColumn { displayName = "Last Name", name = "LASTNAME" },
                    new DojoGridColumn { displayName = "Salary", name = "SALARY" }
            ] };

    function start()
        svc EmployeeService { };
        call svc.getEmployees () returning to displayEmployees;
    end

    function displayEmployees(retResult Employee [ ] in)
        grid.data = retResult as any [ ];
    end
    
end
</syntaxhighlight>