CREATE PAGE

Synopsis

CREATE [ OR REPLACE ] PAGE module.Name [ FOLDER 'path' ]
(
    [ Params: ( $param : Module.Entity | Type [optional] [, ...] ), ]
    Title: 'title',
    Layout: Module.LayoutName
    [, Variables: ( $name : type = <expression> [, ...] ) ]
)
{
    widget_tree
}

Description

Creates a new page in the specified module. A page defines a user interface screen with a title, a layout, optional parameters, and a hierarchical widget tree.

If OR REPLACE is specified and a page with the same qualified name already exists, it is replaced. Otherwise, creating a page with an existing name is an error.

A replace (OR REPLACE or OR MODIFY) is refused when the stored page holds a widget MDL cannot author — a classic data grid, a reference selector, a drop-down, a reference set selector — that the statement does not declare by name, because the rebuilt page would not contain it. DESCRIBE PAGE marks each such widget with a -- NOT re-executable comment, and the error lists them. Change the page with ALTER PAGE, which keeps them, or remove them on purpose first (ALTER PAGE M.P { DROP grid1; };). The same applies to snippets and layouts, and mxcli check -p reports it before anything is written.

Page Properties

The page declaration block ( ... ) contains comma-separated key-value properties:

• Params – Page parameters. Each parameter has a $-prefixed name and a type — either an entity (Module.Entity) or a primitive (String, Integer, Decimal, Boolean, DateTime). Parameters are passed when the page is opened (e.g., from a microflow SHOW PAGE or from a data view). Primitive parameters require Mendix 11.6+. A parameter is required unless it says optional ($Sale: Shop.Sale optional, Studio Pro’s unticked Required, Mendix 11.5+): an optional parameter lets the page be opened with no argument, from a menu item for example, where a required one is CE1571. describe page prints it, and a snippet parameter cannot be optional. A parameter cannot be named with a platform-reserved word — Context, Type, Id, Owner, Object, CurrentUser or a Java keyword, in any case and even quoted: Mendix reports CE7247 “The name ‘Context’ is a reserved word.”, and mxcli check refuses it (MDL-PARAM01). The same holds for snippet, Java action and JavaScript action parameters.
• Title – The page title displayed in the browser tab or page header.
• Layout – The layout the page is based on. Must be a qualified name referring to an existing layout (e.g., Atlas_Core.Atlas_Default, Atlas_Core.PopupLayout).
• Folder – Optional folder path within the module. Nested folders use / separator.
• Variables – Optional page-level variables with default expressions. Variables can be used for conditional visibility and dynamic behavior.

Widget Tree

The widget tree inside { ... } defines the page content. Widgets are nested hierarchically. Each widget has:

• A type keyword (e.g., DATAVIEW, TEXTBOX, ACTIONBUTTON)
• A name (unique within the page, used for ALTER PAGE references)
• Properties in parentheses (Key: value, ...)
• Optional children in braces { ... }

Widget Types

Layout Widgets

Data Widgets

Input Widgets

Display Widgets

Action Widgets

Structure Widgets

DataSource Types

The DataSource property determines how a data widget obtains its data:

Action Types

The Action property determines what happens when the widget is clicked. It is not a button-only property: a CONTAINER is clickable too and takes the same values, including the argument list.

The set is closed. Anything else in an action slot is an error (MDL-WIDGET28), and that includes a real action keyword missing its argument — Action: OPEN LINK with no URL, Action: SHOW PAGE with no page. Such a widget used to be written with no action at all: it rendered, carried its caption, and did nothing, while mxcli check, exec and mxbuild all reported success, because a no-action widget is perfectly legal Mendix. Write NOTHING when a control is genuinely meant to be inert, so that a dead one always means a mistake.

The same values serve OnClick: (an alias of Action:), OnChange: and a text box’s OnEnterKeyPress: — Studio Pro’s On enter key press, which runs when the user presses Enter in the box (a search field that searches on Enter):

TEXTBOX tbSearch (Label: 'Search', Attribute: SearchText,
  OnEnterKeyPress: CALL MICROFLOW Module.ACT_Search(Query = $currentObject))

Only a text box has that action — Mendix stores it on no other widget, a text area included — so on any other widget the key is refused with that reason.

Every input widget (text box, text area, date picker, check box, radio buttons, drop-down) also has Studio Pro’s On enter and On leave — focus moving into and out of the widget, not the Enter key — spelled OnEnter: and OnLeave:, with the same values. The stored names OnEnterAction:, OnLeaveAction: and OnEnterKeyPressAction: are accepted as the same properties; DESCRIBE prints the short ones.

A flow or page that takes no parameters may be called with an empty argument list, as a flow body writes it: Action: CALL MICROFLOW Module.Name() stores exactly what Action: CALL MICROFLOW Module.Name stores, and DESCRIBE writes it without the brackets. The same holds for a microflow or nanoflow data source and for USE FRAGMENT Name().

Action settings

Any action but NOTHING takes a with ( … ) list of the settings Studio Pro shows under the event:

ACTIONBUTTON btnDelete (Caption: 'Delete',
  Action: CALL MICROFLOW Shop.ACT_Order_Delete(Order = $currentObject) with (
    ProgressBar: Blocking, ProgressMessage: 'Deleting…',
    Confirmation: 'Delete this order?', ProceedCaption: 'Delete', CancelCaption: 'Keep'))

A setting left out keeps its default, and DESCRIBE prints only the settings that differ from it. An unknown key, or a setting the action does not have, is an error. For CREATE OBJECT … THEN SHOW PAGE … the list goes at the end and belongs to the create action.

Return value mappings

A microflow or nanoflow call can map what the flow returns back onto the page — Studio Pro’s Return value mappings (Mendix 11.5+). The returns ( … ) list goes after the arguments and before with ( … ), one target = source per row:

DATAVIEW dvVehicle (DataSource: $Vehicle) {
  ACTIONBUTTON btnRefresh (Caption: 'Refresh',
    Action: CALL MICROFLOW Shop.ACT_Vehicle_Get returns (
      Brand = $ActionReturnValue/Brand,     -- an attribute of the returned object
      $stringResult = $ActionReturnValue,   -- the return value itself
      Brand = 'Demo brand'))                -- any expression
}

The source is $ActionReturnValue, $ActionReturnValue/Attr (the flow must return an object that has Attr), or any expression. DESCRIBE prints the stored mappings, and re-running a statement without the list removes them — the statement is the authority. A mapping DESCRIBE cannot spell (a path over an association) is printed as a comment under the widget, saying a re-run drops it.

A microflow or nanoflow action is a call: every parameter the flow declares needs an argument, or Mendix rejects the page with CE1571. An enclosing data container of the parameter’s type supplies it without one — but a data grid’s control bar does not, because it is not row-scoped. Pass the grid’s selection there, addressed by the widget’s own name:

DATAGRID dgOrders (DataSource: DATABASE FROM Sales.Order, Selection: Single) {
  COLUMN (Attribute: Number, Caption: 'Order #')
  CONTROLBAR {
    CONTAINER cShip (Class: 'command',
      Action: CALL NANOFLOW Sales.ACT_Ship(Order = $dgOrders)) {
      ACTIONBUTTON btnShip (Caption: 'Ship')
    }
  }
}

A SHOW PAGE in the control bar takes the selection the same way — Action: SHOW PAGE Sales.Order_Detail(Order = $dgOrders) opens the page with the selected row, and the button is disabled until a row is selected. In a grid with Selection, a SHOW PAGE in a column’s custom content may pass the grid’s selection by name as well, which is what Studio Pro stores there; $currentObject is the row.

A control bar takes its object from above its grid, but sits inside the grid, so the data view around the grid is an outer one there: $dvOrder from the control bar of a grid in data view dvOrder is valid.

mxcli check -p <app.mpr> reports a missing argument before mxbuild does.

ButtonStyle Values

Primary, Default, Success, Danger, Warning, Info.

DataGrid Columns

Inside a DATAGRID, child widgets define columns. Each column widget specifies:

Common Widget Properties

These properties are available on most widget types:

Attributes of a Page or Snippet Parameter

A bare attribute name binds to the enclosing data container’s object. To bind an attribute of a page or snippet parameter instead, whatever container the widget is in, write $Param.Attr. This works for a pluggable widget’s attribute property set by its own key too, such as a Custom chart’s eventDataAttribute: $Ctx.EventData. The qualified name of another entity’s attribute (Module.Other.Attr) is refused, because stored without the parameter it is mx check CE7247.

An enclosing data view is named the same way: inside a data view nested in dvOuter, $dvOuter.Attr reads the outer data view’s object, and $dvOuter/Assoc/Attr reads over an association from it. This works on input widgets, on a pluggable widget’s attribute property (markdown md (stringAttribute: $dvOuter.Output)) and in an attribute-based visibility condition (Visible: $dvOuter.HasError in (true)). It is the form Studio Pro stores for these bindings.

Parameters

module.Name

The qualified name of the page (Module.PageName). The module must already exist.

Params: ( ... )

Optional page parameters. Each parameter has a $-prefixed name and an entity type.

Title: 'title'

The display title of the page. Required.

Layout: Module.LayoutName

The page layout. Must reference an existing layout. Required.

FOLDER 'path'

Optional folder within the module, as a clause after the name. Nested folders use /. The Folder: 'path' property is its deprecated alias (MDL-DEPR105).

Variables: ( ... )

Optional page variables with type and default expression.

Examples

Edit page with a data view and form fields:

CREATE PAGE MyModule.Customer_Edit
(
    Params: ( $Customer: MyModule.Customer ),
    Title: 'Edit Customer',
    Layout: Atlas_Core.PopupLayout
)
{
    DATAVIEW dvCustomer (DataSource: $Customer) {
        TEXTBOX txtName (Label: 'Name', Attribute: Name)
        TEXTBOX txtEmail (Label: 'Email', Attribute: Email)
        COMBOBOX cbStatus (Label: 'Status', Attribute: Status)

        FOOTER {
            ACTIONBUTTON btnSave (Caption: 'Save', Action: SAVE CHANGES, ButtonStyle: Primary)
            ACTIONBUTTON btnCancel (Caption: 'Cancel', Action: CANCEL CHANGES)
        }
    }
};

Overview page with a data grid:

CREATE PAGE Sales.Order_Overview FOLDER 'Orders'
(
    Title: 'Orders',
    Layout: Atlas_Core.Atlas_Default
)
{
    DATAGRID dgOrders (DataSource: DATABASE Sales.Order, PageSize: 20) {
        COLUMN (Attribute: OrderId, Caption: 'Order #')
        COLUMN (Attribute: OrderDate, Caption: 'Date')
        COLUMN (Attribute: Status, Caption: 'Status')
        COLUMN (Attribute: TotalAmount, Caption: 'Amount', Alignment: right)
        CONTROLBAR {
            ACTIONBUTTON btnNew (Caption: 'New Order', Action: SHOW PAGE Sales.Order_Edit, ButtonStyle: Primary)
        }
    }
};

Page with layout grid and containers:

CREATE PAGE MyModule.Dashboard
(
    Title: 'Dashboard',
    Layout: Atlas_Core.Atlas_Default
)
{
    LAYOUTGRID lgMain {
        ROW {
            COLUMN (Class: 'col-md-8') {
                CONTAINER cntRecent (Class: 'card') {
                    LISTVIEW lvRecent (DataSource: DATABASE MyModule.RecentActivity, PageSize: 5) {
                        DYNAMICTEXT txtDesc (Attribute: Description)
                    }
                }
            }
            COLUMN (Class: 'col-md-4') {
                CONTAINER cntStats (Class: 'card') {
                    DATAVIEW dvStats (DataSource: MICROFLOW MyModule.DS_DashboardStats) {
                        DYNAMICTEXT txtCount (Attribute: TotalCount)
                    }
                }
            }
        }
    }
};

Page with snippet call:

CREATE PAGE MyModule.Customer_Detail
(
    Params: ( $Customer: MyModule.Customer ),
    Title: 'Customer Detail',
    Layout: Atlas_Core.Atlas_Default
)
{
    DATAVIEW dvCustomer (DataSource: $Customer) {
        SNIPPETCALL snpHeader (Snippet: MyModule.CustomerHeader)
        TEXTBOX txtName (Label: 'Name', Attribute: Name)
        TEXTBOX txtEmail (Label: 'Email', Attribute: Email)
    }
};

Page with a gallery and selection-driven detail:

CREATE PAGE Sales.Product_Gallery
(
    Title: 'Products',
    Layout: Atlas_Core.Atlas_Default
)
{
    LAYOUTGRID lgMain {
        ROW {
            COLUMN (Class: 'col-md-6') {
                GALLERY galProducts (DataSource: DATABASE Sales.Product, PageSize: 12) {
                    DYNAMICTEXT txtName (Attribute: Name)
                    DYNAMICTEXT txtPrice (Attribute: Price)
                }
            }
            COLUMN (Class: 'col-md-6') {
                DATAVIEW dvDetail (DataSource: SELECTION galProducts) {
                    TEXTBOX txtName (Label: 'Product', Attribute: Name)
                    TEXTBOX txtDesc (Label: 'Description', Attribute: Description)
                }
            }
        }
    }
};

Page with page variables and conditional visibility:

CREATE PAGE MyModule.AdvancedForm
(
    Params: ( $Item: MyModule.Item ),
    Title: 'Advanced Form',
    Layout: Atlas_Core.Atlas_Default,
    Variables: ( $showAdvanced: Boolean = false )
)
{
    DATAVIEW dvItem (DataSource: $Item) {
        TEXTBOX txtName (Label: 'Name', Attribute: Name)
        ACTIONBUTTON btnToggle (Caption: 'Show Advanced', Action: CALL NANOFLOW MyModule.NAV_Toggle)
        CONTAINER cntAdvanced (Visible: '$showAdvanced') {
            TEXTAREA taNotes (Label: 'Notes', Attribute: Notes)
        }
        FOOTER {
            ACTIONBUTTON btnSave (Caption: 'Save', Action: SAVE CHANGES, ButtonStyle: Primary)
            ACTIONBUTTON btnCancel (Caption: 'Cancel', Action: CANCEL CHANGES)
        }
    }
};

Page with microflow data source:

CREATE PAGE Reports.MonthlySummary
(
    Title: 'Monthly Summary',
    Layout: Atlas_Core.Atlas_Default
)
{
    DATAVIEW dvReport (DataSource: MICROFLOW Reports.DS_GetMonthlySummary) {
        DYNAMICTEXT txtPeriod (Attribute: Period)
        DYNAMICTEXT txtRevenue (Attribute: TotalRevenue)
        DYNAMICTEXT txtOrders (Attribute: OrderCount)
    }
};

See Also

CREATE SNIPPET, ALTER PAGE, DROP PAGE, DESCRIBE PAGE, GRANT VIEW ON PAGE