program basicConsole type BasicProgram
function main()
myWindow Window {name = "My Window",
position = [1,1]};
myConsoleRec CustomerConsoleRecord{name = "myForm"};
ConsoleLib.openWindow(myWindow);
ConsoleLib.displayForm(myConsoleRec);
end
end
Record CustomerConsoleRecord type consoleForm
{formSize = [10,40],name = "Customer Record"}
* consoleField {position = [1,4],
value = "Welcome to my console."};
ID consoleField {fieldLen = 5, position = [3,4],
name="customer_id"};
Fname consoleField {fieldLen = 20, position = [4,4],
name="first_name"};
Lname consoleField {fieldLen = 20, position = [5,4],
name="last_name"};
PhoneNum consoleField {fieldLen = 20, position = [6,4],
name="phone"};
end
However, this interface is not very useful because it does not enable the user to interact with the form or window at all. Because this form does not enable any interaction, the window closes as soon as it opens. You need to bind EGL variables to the fields with the openUI statement to make the fields on the interface meaningful and keep the window open while the user works with the interface.
Like many other types of applications with user interfaces, Console UI applications separate the interface from the data being managed by the interface. When you create a Console UI in EGL, you create the interface with parts like consoleForms and then use the openUI statement to connect, or bind, those parts to variables in your program. Then, when the person using the interface changes a value in the consoleForm, the value of the variable changes to match. Conversely, when your code changes the value of the variable, the value in the form changes to match.
program basicConsole type BasicProgram
function main()
myWindow Window {name = "My Window", position = [1,1]};
myConsoleRec CustomerConsoleRecord{name = "myForm"};
ConsoleLib.openWindow(myWindow);
ConsoleLib.displayForm(myConsoleRec);
customer_id int;
first_name, last_name, phone char(30);
openUI myConsoleRec
bind customer_id, first_name, last_name, phone
end
end
end
Record CustomerConsoleRecord type consoleForm
{formSize = [10,40],name = "Customer Record"}
* consoleField {position = [1,4],
value = "Welcome to my console."};
ID consoleField {fieldLen = 5, position = [3,4],
name="customer_id"};
Fname consoleField {fieldLen = 20, position = [4,4],
name="first_name"};
Lname consoleField {fieldLen = 20, position = [5,4],
name="last_name"};
PhoneNum consoleField {fieldLen = 20, position = [6,4],
name="phone"};
end
Now when you run this program, the window stays open so the user can tab through the fields and type values. The line of code that begins openUI myConsoleRec bind customer_id... specifies that the fields in the myConsoleRec are bound to the variables listed in the bind clause.
For your Console UI to react to actions that the user performs in the form, you must define event handlers that tell EGL what to do in response to the action. An event handler contains EGL statements like a function, but it begins with a description of an event, such as a key being pressed or a value being typed in a field. When the user presses a key or types a value in a field, the event handler that is associated with that action is called.
program basicConsole type BasicProgram
function main()
myWindow Window {name = "My Window", position = [1,1]};
myConsoleRec CustomerConsoleRecord{name = "myForm"};
ConsoleLib.openWindow(myWindow);
ConsoleLib.displayForm(myConsoleRec);
customer_id int;
first_name, last_name, phone char(30);
openUI myConsoleRec
bind customer_id, first_name, last_name, phone
onEvent(AFTER_FIELD:"customer_id")
if (customer_id == 3)
first_name = "John";
end
end
end
end
Record CustomerConsoleRecord type consoleForm
{formSize = [10,40],name = "Customer Record"}
* consoleField {position = [1,4],
value = "Welcome to my console."};
ID consoleField {fieldLen = 5, position = [3,4],
name="customer_id"};
Fname consoleField {fieldLen = 20, position = [4,4],
name="first_name"};
Lname consoleField {fieldLen = 20, position = [5,4],
name="last_name"};
PhoneNum consoleField {fieldLen = 20, position = [6,4],
name="phone"};
end
program menuTest type BasicProgram
function main()
openUI
new Menu {labelText = "Choose an option",
menuItems = [
new MenuItem{name = "One",labelText = "Option One"},
new MenuItem{name = "Two",labelText = "Option Two"},
new MenuItem{name = "Exit",labelText = "Exit"}
]}
onEvent(MENU_ACTION:("Exit"))
exit openUI;
onEvent(MENU_ACTION:("One"))
consolelib.displayAtLine("You chose option One", 5);
onEvent(MENU_ACTION:("Two"))
consolelib.displayAtLine("You chose option Two", 5);
end
end
end
In this example, the window provides a feedback message when the user selects one of the first two options and closes when the user selects the "Exit" menu option.
For other kinds of event handlers, see openUI.