SHOW operator

The SHOW operator creates an action that opens a form in interactive view.

Syntax

SHOW [formId =] target
    [formActionOptions]
    [{initActionOperator}]

Where target is one of two forms — the named-form opens a previously declared form:

formName [OBJECTS objName1 = expr1 [NULL], ..., objNameN = exprN [NULL]]

and the class-form opens the list or edit form of a class:

classFormType className = expr [NULL]

And formActionOptions is any combination of the following options, in any order:

FILTERS filterExpr1, ..., filterExprM
syncType
windowType
manageSessionType
sessionScopeType
cancelType
READONLY
CHECK

Where windowType is one of:

FLOAT
DOCKED
EMBEDDED
POPUP
IN containerName

Description

The SHOW operator creates an action that opens the specified form. The OBJECTS block sets initial values for the form's objects (in the class-form, the single = expr plays the same role for the form's only object, which is implicitly named object and can be referenced by that name inside FILTERS expressions). Inside formActionOptions, the FILTERS clause attaches additional filters computed from the calling context; the remaining options control the form-opening behavior — flow, layout, session, system-action visibility, and other modifiers. The trailing block {initActionOperator} runs once when the form is opened.

Parameters

• formId

  String literal that uniquely identifies the opened form instance for later form-management actions (for example, to close that exact form). By default, the opened form has no such identifier.

• formName

  Form name. Composite ID.

• classFormType

  Type of the class form to open. It is specified by one of the keywords:

  • LIST — the selection (list) form
  • EDIT — the editing form

• className

  Name of the custom class whose list or edit form is opened. Composite ID.

• objName1, ..., objNameN

  Names of form objects for which initial values are specified. Simple IDs.

• expr, expr1, ..., exprN

  Expressions whose values are used as the initial values of the corresponding form objects.

• NULL after the initial value

  Keyword. Allows the passed initial value to be NULL. By default, if any passed value is NULL, the action is skipped and control passes to the next action.

• initActionOperator

  Context-dependent action operator that runs on form opening, after the form's EVENTS ON INIT handlers.

Options

• filterExpr1, ..., filterExprM

  Non-empty list of expressions that define additional filters applied to the form. Each expression can use both the calling context parameters and the form's own objects.

• syncType

  The flow-control mode. One of:

  • WAIT — synchronous (wait for the form to close)
  • NOWAIT — asynchronous (continue immediately after opening)

  By default, the platform picks WAIT when the call is itself made from a modal form, when more session usages will follow in the same call, or when the chosen window-type is itself modal (FLOAT, EMBEDDED, POPUP); otherwise NOWAIT.

• windowType

  The form layout: FLOAT shows the form as a floating window, DOCKED as a tab in the system forms window, EMBEDDED and POPUP as in-place editors, and IN places the form inside containerName — a form-qualified design component (the form's name followed by the component's path within that form's design) that must be a container. By default, FLOAT is used in synchronous mode and DOCKED in asynchronous mode.

• manageSessionType

  Overrides whether the opened form is the session owner. One of:

  • MANAGESESSION — force ownership
  • NOMANAGESESSION — force non-ownership

  By default, the form is the session owner only if the session has no other owner at opening time.

• sessionScopeType

  The session in which the form is opened. One of:

  • NEWSESSION — a new top-level session
  • NESTEDSESSION — a new nested session
  • THISSESSION — the current session (default)

• cancelType

  Overrides whether the Cancel system action (System.formCancel[]) is shown on the form. One of:

  • CANCEL — force visible
  • NOCANCEL — force hidden

  By default, it is shown if the form is the session owner and the form contains actions that can change the session.

• READONLY

  Keyword. If specified, the form is opened in read-only mode.

• CHECK

  Keyword. If specified, when the user presses the OK system action (System.formOk[]), the platform first validates the pending session changes (runs the apply pass — constraints, aggregations, event handlers — without committing); the form closes only if the validation passes, otherwise it stays open.

Examples

date = DATA DATE (Order);
FORM showForm
    OBJECTS dateFrom = DATE, dateTo = DATE PANEL
    PROPERTIES VALUE(dateFrom), VALUE(dateTo)

    OBJECTS o = Order
    FILTERS date(o) >= dateFrom, date(o) <= dateTo
;

testShow ()  {
    // initial values for two objects, init action after opening
    SHOW showForm OBJECTS dateFrom = 2010_01_01, dateTo = 2010_12_31 { MESSAGE 'On init'; };

    // open in a new session as a floating window, with the new object as the current one
    NEWSESSION {
        NEW s = Sku {
            SHOW sku OBJECTS s = s FLOAT;
        }
    }

    // open the named form with panel values, an additional filter, and an instance identifier
    SHOW 'recentOrders' = showForm OBJECTS dateFrom = 2024_01_01, dateTo = 2024_12_31 FILTERS number(o) > 1000 NOWAIT;

    // open the list form of the Sku class, focused on a specific sku
    NEW s = Sku { SHOW LIST Sku = s; }
}