# Data Classes

Check Box Data Class |

When creating or editing a data class for a Check Box control type, Data Class Definitions maintenance displays the following:

#### Note:
Properties marked with an * (asterisk) can be dynamic. Expressions that come from a data class must be global variables. See Dynamic Control Properties.

The following tabbed panels are available: Display, Attributes, User Aids and Validation.

Class Name | Key to the data classes file (providex.dcl). When entering a new data class name, spaces are not allowed. Maximum length is 30 characters. Click the Query button (binoculars) for a list of defined data classes (if any). Click the Browse buttons to browse to existing data classes. Click the Copy Class button to copy an existing data class to a new data class. If unsaved changes are detected when selecting these buttons, a message will display to save the changes. (First/Last Class browse buttons were added in PxPlus 2019.)
(Add/Edit Notes) | (Available when a new or existing data Class Name is entered or selected) Button used to add (or edit) notes for a new or existing data class. Maximum 1024 characters. The button's appearance and tooltip change to indicate that a note was added for the data class. (The Add/Edit Notes button was added in PxPlus 2022.)
(Copy Class) | (Available when an existing data Class Name is selected) Button used to create a new data class by copying the settings from an existing data class. Once it is created, the new data class must be saved, as the Copy process does not do this. (The Copy Class button was added in PxPlus 2019.)
Last Class Change | This information is updated automatically whenever a change is made to the data class definition. (Last Class Change was added in PxPlus 2023.)
Control Type | Default control type used to represent the data that belongs to your defined data class. Click the drop-down arrow for a list of selections: Multi Line, Drop Box, List Box, Radio Buttons, Check Box. (Default is Multi Line.) The control type lets the NOMADS Panel Designer and File Maintenance Generator know which type of control to use for representing the data element.
Description | Generic description of the data class (Fixed value, Expression or Message Library Reference). This will be copied to the data dictionary when the data class is applied to an element. See Element Description.
*Dynamic | For new data classes created in PxPlus 2018, this check box is selected by default. For data classes created prior to PxPlus 2018, this check box is not selected by default. Select this check box to set dynamic control properties to Dynamic automatically when the data class is entered for a control in the Panel Designer. If Dynamic is not selected, dynamic control properties must be set to Dynamic manually after entering the data class for a control. See Dynamic Control Properties. (The Dynamic check box was added in PxPlus 2018.)
Internal Data Type | Internal format of the data when manipulated by a program, either String or Numeric. (Default is String.)
Internal Size | Maximum size of the stored data element. When the Control Type is Check Box, the Internal Size is 1.
Display ( * indicates a Dynamic property)
Properties |
Check Box Width | Width of the control in number of columns - numeric expression. Format mask is ##0.00 and valid entries are 0 to 255.
Bitmaps | Sets the button bitmap. Click the Bitmap Library button to select a bitmap from the Bitmaps dialogue for the state, if applicable.
*Off State | Bitmap shown when button is in the "Off" (normal) state.
*On State | Bitmap shown when button is in the "On" state.
*3rd State | (Applicable when Tri-State Check Box (Attributes tab) is selected) Bitmap shown when button is in an optional third state. See Tri-state Check Box below.
Alignment | Sets the bitmap alignment. Click the drop-down arrow for a list of selections: Left, Right, Top, Bottom, Center/Scale. Selecting Center/Scale alignment also forces the selection of the Scale bitmap option.
Scale bitmap | Scales the bitmap to fit the button size. Any button text is forced to be aligned Center/Scale. #### Note: Top, Bottom and Center/Scale alignments and the Scale bitmap option only work in 4D mode.
(Bitmaps definitions for up to three states was added in PxPlus 2018.) (The Center/Scale alignment and Scale bitmap options were added in PxPlus 2019 Update 1.)
*Image Options | (Available when Bitmaps for Off/On/3rd States are selected) Sets advanced image options for the bitmap. Click the Additional Image Options button to the right of the Image Options multi-line to invoke the Image Options dialogue. This dialogue consists of the following:
Options |
Image Transparency | Bitmap transparency option. Click the drop-down arrow for a list of selections: None, Pixel sets transparency or 'Light Gray' is transparent.
Flip Image | Flips the image. Click the drop-down arrow for a list of selections: None, Flip horizontally (left/right), Flip vertically (up/down) or Flip horizontally and vertically.
Rotation Angle | Counter clockwise rotation angle at which to display the image. Valid entries are 0 to 359.
Invert Image | Displays the image with inverted colors.
Gray Scale Image | Converts the image to gray scale.
Cropping (Pixels from Top/Left of Image (0,0)) | Define the cropped image in terms of Left, Right, Top and Bottom where these values are the number of pixels from the top left corner (0,0) of the image.
#### Note: Image Transparency and Cropping are not supported in iNomads. (The Image Options dialogue was added in PxPlus 2019.)
*Visual Class | Assign visual class to the control. See Visual Class Assignment. #### Note: Visual class names that begin with an "*" (asterisk) are pre-defined visual classes used by PVX Plus and may be subject to change without notice.
*iNomads Class | The iNomads class contains class attribute references used when defining the control in the HTML code generated in iNomads. An iNomads class reference must start with an alpha character (A-Z or a-z), followed by any combination of A-Z, a-z, 0-9, underscore or dash. Multiple references may be entered, separated by a space. For a list of pre-defined iNomads classes, see iNomads Classes.
Attributes ( * indicates a Dynamic property)
Attributes |
Auto Tab Skip | Control is skipped when tabbing forward but is still accessible via Shift - Tab or the mouse.
Initially Disabled | Control region is grayed out and is not accessible to the user for input. The control is accessible programmatically.
Initially Hidden | Control is not displayed but is accessible programmatically.
Button to the Right of Text | Bitmap will display after the text. This is only applicable if the Check Box does not contain a bitmap. (added in PxPlus 2018)
Numeric | Returns a value for the control in a numeric variable.
Signal Only (No Focus) | PxPlus generates a CTL value but does not shift focus to the button automatically (default) unless focus is explicitly passed. (added in PxPlus 2018)
Hover Cursor | Controls the type of cursor to display whenever the mouse moves over the control. Options are: Default, Arrow, Wait, Insert, Movement arrows, Sizing arrow, Hand, Crossed hand, Rabbit in hat, Happy face, Sad face, Up/Down arrow, Left/Right arrow and Not allowed. (added in PxPlus 2018)
Tri-State Check Box | Creates a Check Box that includes a third state. User will be able to toggle between three states: On, Off and an optional Third State.
Enable Scrolling | Allows the control to scroll in a resizable/scrollable dialogue box. See Panel Resizing.
Flat Button | Button shows no raised outline unless the mouse is over the button or the button is pressed. (added in PxPlus 2018)
Bitmap Button | Button has a bitmap whose width is divided into four images. Use this to custom design buttons with any color, style or shape by controlling the image that appears. (added in PxPlus 2018)
Sticky Button | 'Sticky' functionality, which means that the button remains in the "pressed" position until the next selection.(added in PxPlus 2018)
Hover Color | Text on the button is highlighted whenever the mouse is over the button area. The default color is controlled by the 'HC' system parameter that defaults to 'Light Blue'. (added in PxPlus 2018)
Flat - No Border | Button has no border and shows no raised outline unless the button is pressed. (added in PxPlus 2018)
Transparent | Button is transparent; i.e. the window contents behind the button show through. This style can be used to place buttons onto bitmaps. (added in PxPlus 2018)
Drop-List Button | Extra button with an arrow bitmap is attached to the right of the main button. When the arrow bitmap button is clicked, the associated popup menu is displayed. (added in PxPlus 2018)
Ignore Change Flag | Select this check box when you do not want the NOMADS CHANGE_FLG variable to be updated when the control value is changed. (added in PxPlus 2017)
Check Box Corner Radius | (Available for Standard Check Boxes - Without Bitmap) Sets the corner radius for a check box that looks like a check box (no bitmap defined), not for a check box that looks like a normal button. Works only in 4D mode. See CbCornerRadius$ property. When a bitmap is added, this option is replaced by the Button Corner Radius option. Possible values are Null (blank), Round, Square or a value from 0 to 255 inclusive. Example: (Check Box Corner Radius was added in PxPlus 2026.)
Button Corner Radius | (Available for Check Box Buttons - With Bitmap) Sets the corner radius for a check box only when it is drawn as a button, which occurs when a bitmap is added. Works only in 4D mode. See CornerRadius$ property. When no bitmap is added, this option is replaced by the Check Box Corner Radius option. Possible values are Null (blank), Round, Square or a value from 0 to 255 inclusive. Example: (Button Corner Radius was added in PxPlus 2026.)
*User Tag Field | For controls, data/tag field which can be used to pass information on such things as formatting, error messages or validation rules. Field contents are placed in a variable using the control name with a .TAG$ extension.
User Aids ( * indicates a Dynamic property)
*Help Reference |
Type | Click the drop-down arrow to select either Internal or External help reference:
Internal | Application supplied message text (Fixed value, string Expression or Message Library Reference).
External | Standard Windows help system consisting of a help file name and an optional keyword or reference number (Fixed or Expression).
*Floating Tip | Mouse pointer message for the control (Fixed value, string Expression or Message Library Reference). You can customize the floating tip by adding a tip title, descriptive tip text and a hyperlink. These features enhance the visual display and functionality of the tip by providing users with much needed information at their fingertips. You can define either a Standard tip or an HTML tip that provides a simplified HTML Editor for customizing the tip text. To do this, click the button to the right of the Floating Tip multi-Line input to invoke the Define Info Tip dialogue. See Defining an Info Tip. #### Note: The Floating Tip drop box and multi-line input cannot be changed once an HTML tip has been defined.
*Message Bar | Text to be displayed in the panel's status bar when focus is on the control (Fixed value, string Expression or Message Library Reference).
Validation ( * indicates a Dynamic property)
*Default Setting | Initial value to be applied when the Check Box is drawn.
*Values |
Value in 'Off' State | Value to return when the Check Box is turned Off. Can be a numeric value or a single character translation value.
Value in 'On' State | Value to return when the Check Box is turned On. Value can be a numeric value or a single character translation value.
Tri-State Check Box | Creates a Check Box that includes a third state. User will be able to toggle between three states: On, Off and an optional Third State. See Value in '3rd' State below.
Value in '3rd' State | Value to return for the 3rd State. Can be a numeric or a single character translation value. Requires Tri-state Check Box to be selected. See Attributes above.
Popup Menu | Button that is used to assign a popup menu to a data class (Fixed value or Expression, to be evaluated at run time when the popup signal occurs). A check mark displayed on the button indicates that a popup menu is currently assigned to the data class. This button invokes the Assign Popup Menu window for assigning Prior Popup logic, a pre-defined popup object or user-defined program. If selected, Prior Popup logic will be executed before the popup menu is displayed. If On Select logic exists for the control with the popup menu, this will be triggered before the popup event. Select the Panel option in the Assign Popup Menu window to display a pre-set list of popup objects available for the highlighted library. The Program option is used to add a user-defined program. This can be either a Fixed value or Expression to be evaluated at run time when the popup signal occurs.
Write | Adds a new data class definition or updates an existing definition.
Delete | (Available when an existing data class is selected) Removes the selected data class definition. Before proceeding, a message asks to confirm the deletion, as deleting a data class in use may cause issues.
Clear | Clears the current data class definition to allow you to define a new data class or select an existing definition.
Exit | Closes Data Class Definitions maintenance without saving any changes.

(The Display and User Aids tabs were added in PxPlus 2018.)