Designing DataWindow objects for the Web DataWindow

The Web DataWindow supports most PowerBuilder DataWindow functionality. This section describes what features to use to take full advantage of the Web DataWindow.

Use default properties of DataWindow column edit styles The properties of DataWindow column edit styles default to values that optimize their appearance—for example, radio buttons are left aligned. If you must change these style properties, the appearance of a column in the Web DataWindow might differ from its appearance in the DataWindow painter because the browser manages the rendering of HTML controls. You can adjust the appearance of the Web DataWindow by repositioning the control or resizing the column.

Using existing DataWindow objects

Many existing DataWindow objects work in the Web DataWindow. If a DataWindow object uses features that the Web DataWindow does not support, then the features are ignored. You can still use the DataWindow object if the remaining functionality is acceptable for your application. For example: if the DataWindow includes a graph control, the graph is ignored; if the DataWindow uses the Graph presentation style, the DataWindow object will not be useful.

Supported and unsupported features

**Table 6-3: Web DataWindow supported and unsupported features**
DataWindow feature	Supported and unsupported features
Presentation styles	All presentation styles except OLE, Graph, and RichText are supported. Unsupported presentation styles retrieve data but display nothing. The Grid presentation style is rendered as an HTML table if you use the HTML format, and as a result absolute positioning is not supported and the display characteristics differ from those of XML and XHTML Web DataWindows.
Nested and composite reports	Supported for the XHTML format only.
Controls	Supported controls: Column, Computed Field, Graph, Text, Picture, Button, GroupBox, Rectangle. These controls are ignored: OLE Object, OLE Database Blob, RoundRectangle, Oval, InkPicture. Report controls are supported in XHTML Web DataWindows only. Rectangles cannot be rendered in a Label DataWindow with any rendering format when the layer of the Rectangle is foreground, unless the height of the DataWindow control is set to a fixed value. The following Rectangle properties are not supported: moveable, pointer, resizeable, slideleft, slideup, brush.hatch, pen.style GroupBoxes cannot be rendered in Crosstab and Grid style DataWindows. The following GroupBox properties are not supported: moveable, pointer, resizeable, slideleft, slideup, font.charset, font.width. Only horizontal Line controls are supported. The line’s color property is always rendered, and the width property is rendered if the line is solid. Other line styles are displayed as solid lines with the default width. Vertical and slanted lines are ignored. For information on: Expressions for computed fields, see “Using expressions”. Images for Picture controls, see “Using Picture controls”. Including valid HTML in a control, see “Including HTML in a control” Button controls and supported actions, see “Using Button controls”.
Retrieving data	Up to 16 retrieval arguments are supported. Filtering and sorting are supported by setting properties with the Modify method or calling methods on the server component. Sorting can also be specified by using a client control method. User-specified queries using the QueryMode property are not supported.
Updating data	Same as the PowerBuilder DataWindow control. The DataWindow object must contain editable columns.
Edit styles	All edit styles are supported except InkEdit and EditMask, with the exception of the DDCalendar EditMask. If the DataWindow uses the EditMask edit style, the styles specified are treated as though they were specified as a display format.
DDCalendar EditMask property	The DDCalendar EditMask property option allows for separate selections of the calendar month, year, and date. This option can be set in a check box on the Edit tab of the DataWindow painter Properties view when a Date or DateTime column with the EditMask edit style is selected. It can also be set in code, as in this example for the birth_date column: dwEmp.Modify("birth_date.EditMask.DDCalendar='Yes'") For more information, see “Using a drop-down calendar”.
DropDownDataWindows	A drop-down DataWindow must be in the same PBL as the DataWindow in which it is used. Data for drop-down DataWindows is retrieved on the server. See “Using drop-down DataWindows”. The dddw.lines property is not supported in Web pages because the browser controls how the DropDownDataWindow displays.
Display formats	Supported, including the use of color.
Validation rules	The expression might be evaluated on the client or the server, depending on the expression. For information, see “Using expressions”.
Property expressions	Evaluated on the server.
Layout	Properties that specify autosizing of height and width or allow the user to resize or move controls, such as SlideLeft and SlideRight, are ignored.
Properties	The following properties are not supported: EditMask.Spin DataWindow object property Sparse (Suppress Repeating Values) DataWindow object property RightToLeft DataWindow control property The ShowConnectLines and ShowLeafNodeConnectLines properties of the TreeView Web DataWindow The Limit property is not supported in multiline edit columns in a Web DataWindow. In JavaScript, the multiline edit column maps to a textarea object, and the limit property maps to a maxlength attribute, which the textarea object does not support.
Tab order	Supported in HTML 4 and later browsers.

Using a drop-down calendar

The drop-down calendar DataWindow option is available for use on any DataWindow column with an EditMask, and a Date, DateTime, or TimeStamp datatype. The DDCalendar EditMask property option allows for separate selections of the calendar month, year, and date. This option can be set in a check box on the Edit tab of the DataWindow painter Properties view when a column with the EditMask edit style is selected. It can also be set in code, as in this example for the birth_date column:

dw_1.Modify("birth_date.EditMask.DDCalendar='Yes'")

You can set the following properties to control the display of the calendar in a script or on the Other page in the Properties view for the column:

Painter option	Property
Drop Align Right	Column.Editmask.ddcal_alignright
CalendarBackColor	Column.Editmask.ddcal_backcolor
CalendarTextColor	Column.Editmask.ddcal_textcolor
CalendarTitleBackColor	Column.Editmask.ddcal_titlebackcolor
CalendarTitleTextColor	Column.Editmask.ddcal_titletextcolor
CalendarTrailingTextColor	Column.Editmask.ddcal_trailingtextcolor

To make sure that dates selected with the drop-down calendar option are displayed with the desired edit mask for Web DataWindows, you should specify that the Client Formatting option be included with the static JavaScript generated and deployed for the DataWindow. To conserve bandwidth, JavaScript for client formatting is not included by default. To include this script, you can select the Client Formatting check box on the Web Generation page of the DataWindow Properties view. If you do not include script for client formatting, the drop-down calendar will use a default edit mask to display the column data based on the client machine’s default localization settings.

To navigate in the drop-down calendar, a user can:

Click the arrows in the top corners to move from month to month.
Click the month to display a list of months, then click a month to select it.
Click the year to display a spin control, then use the spin control’s arrows to select a year.
Click a date to select the date and close the calendar.
Press the Esc key to close the calendar without changing the selection.