Class

WebButton

Description

The standard button used for web apps.

Methods

Name

Parameters

Returns

Shared

Close

ExecuteJavaScript

script As String

GotoURL

URL As String, inNewWindow As Boolean = False

Press

SetFocus

UpdateBrowser

Events

Name

Parameters

Returns

Closed

ContextualMenuSelected

hitItem As WebMenuItem

Hidden

MenuSelected

item As WebMenuItem

Opening

Pressed

Shown

Property descriptions

WebButton.AllowAutoDisable

AllowAutoDisable As Boolean

When True, the button is automatically disabled after it is pressed. The Pressed event handler must be implemented for the button to disable. To re-enable the button set its Enabled property to True.

Me.AllowAutoDisable = True

WebButton.Cancel

Cancel As Boolean

If True, the Escape key and Command/Control-Period key sequence trigger the Pressed event.

The Cancel property can only be set to True for a single button each per page at any given moment.

When Cancel is True, the Indicator property is ignored as Cancel buttons have a default indicator.

This example makes the WebButton a cancel button. It is in the Opening event of the control.

Me.Cancel = True

WebButton.Caption

Caption As String

Gets or sets the text of the button.

Buttons can only have a single-line caption.

This code in the Pressed event handler changes the text of the button each time it is pressed:

If Me.Caption = "Blue" Then
  Me.Caption = "Red"
Else
  Me.Caption = "Blue"
End If

WebButton.ContextualMenu

ContextualMenu As WebMenuItem

If you assign a WebMenuItem to the control, it will be displayed when the user right-clicks the control.

On a WebPage, you can disable/remove the default contextual menu by an empty WebMenuItem class object to this property.

This code populates a contextual menu in the Shown event of the control.

Var menu As New WebMenuItem

menu.AddMenuItem("One")
menu.AddMenuItem("Two")
menu.AddMenuItem("Three")
Me.ContextualMenu = menu

The menu selection is then handled by the ContextualMenuSelected event when the user right-clicks on the control. For example, it can be of the form:

Select case hitItem.Text
Case "One"
  MessageBox("One")
Case "Two"
  MessageBox("Two")
Case "Three"
  MessageBox("Three")
End Select

WebButton.ControlID

ControlID As String

Identifies the control on a per session basis.

This property is read-only.

WebButton.Default

Default As Boolean

If True, the default button indicator is added to the button and the Return and Enter keys will trigger the Pressed event.

Because there can logically only be one default button per page, only the first WebButton on a page with the Default property set to True will be honored.

When Default is True, the Indicator property is ignored as Default buttons have a default indicator.

This code sets the WebButton as the default button. It is in the Opening event of the control.

Me.Default = True

WebButton.Enabled

Enabled As Boolean

When True the WebControl is drawn enabled and responds to user action. When False, the control appears as disabled and does not respond to user actions.

In the case of WebTimer, when set to False this disables and stops the WebTimer. When set to True, it starts the WebTimer.

Disable a button when a check box value changes:

If AllowSaveCheckBox.Value Then
  SaveButton.Enabled = True
Else
  AllowSaveButton.Enabled = False
End If

WebButton.Height

Height As Integer

The height (in pixels) of the control.

WebButton.Indicator

Indicator As Indicators

The color scheme for the control.

When a WebButton's Default or Cancel properties are True, the Indictor property is ignored as Default and Cancel buttons have a default indicator.

WebButton.Left

Left As Integer

The position of the left side of the WebUIControl in pixels, relative to the web page.

WebButton.LockBottom

LockBottom As Boolean

Determines whether the bottom edge of the control should stay at a set distance from the bottom edge of the parent control, if there is one, or the owning web page.

This property is read-only.

WebButton.LockHorizontal

LockHorizontal As Boolean

LockHorizontal overrides LockLeft and LockRight. It allows you to proportionally lock a control's position to the center of its parent control (or web page).

This property is read-only.

For example, if you place a control in the center of the page and sets both LockHorizontal and LockVertical, the control will stay in the center of the page.

WebButton.LockLeft

LockLeft As Boolean

Determines whether the left edge of the control should stay at a set distance from the left edge of the parent control, if there is one, or the owning web page.

This property is read-only.

WebButton.LockRight

LockRight As Boolean

Determines whether the right edge of the control should stay at a set distance from the right edge of the parent control, if there is one, or the owning web page.

This property is read-only.

WebButton.LockVertical

LockVertical As Boolean

LockVertical overrides LockTop and LockBottom. It allows you to proportionally lock a control's position to keep it centered within the parent control or web page.

This property is read-only.

For example, if you place a control in the center of the page, and sets both LockHorizontal and LockVertical, the control will stay in the center of the page.

WebButton.Menu

Menu As WebMenuItem

The Menu associated with this button. When a menu is associated with the button, it appears in a section separate from the rest of the button which includes an indicator that a menu is available.

Selecting an item from the menu will cause the MenuSelected event to execute.

This code (in the control's Opening event) adds a menu to the button:

Var theMenu As New WebMenuItem
theMenu.AddMenuItem("Yes")
theMenu.AddMenuItem("No")
theMenu.AddMenuItem("Maybe")
Me.Menu = theMenu

WebButton.Name

Name As String

The name of the control.

This property is read-only.

WebButton.Page

Page As WebPage

Identifies the web page that contains the control.

This property is read-only.

WebButton.Parent

Parent As WebControl

Used to get the control's parent control or page. If the parent control is a WebContainer, then it returns the WebContainer. If it is on a WebPage, it returns the WebPage.

This property is read-only.

WebButton.Style

Style As WebStyle

The WebStyle for the control.

In the Pressed event of a WebButton, set the text to bold:

Var style As New WebStyle
style.Bold = True
Me.Style = style

WebButton.TabIndex

TabIndex As Integer

The WebUIControl's control's position in the Tab Order. The control with a TabIndex of 0 is the first WebUIControl to get the focus when the page opens in the browser.

This example sets the control's TabIndex.

Me.TabIndex = 2

WebButton.Tooltip

Tooltip As String

Text of a message displayed as a tooltip.

The tip is displayed when the user places the mouse on the control and leaves it there.

This code in the Shown event of a Button sets the tooltip:

Me.Tooltip = "Save changes"

WebButton.Top

Top As Integer

The top of the control in local coordinates relative to the web page.

WebButton.Visible

Visible As Boolean

If True, the control is drawn. If False, it's not.

Hide a control based on a checkbox setting:

If ShowEmailCheckbox.Value Then
  EmailField.Visible = True
Else
  EmailField.Visible = False
End If

WebButton.Width

Width As Integer

The width (in pixels) of the web control.

This code in the Shown event handler increases the size of the control:

Me.Width = Me.Width + 50

Method descriptions

WebButton.Close

Close

Removes the control from the page.

WebButton.ExecuteJavaScript

ExecuteJavaScript(script As String)

Executes the JavaScript passed. The JavaScript passed can call a JavaScript function in a WebPageSource control.

The Xojo web framework uses EcmaScript 6 which is more strict than previous versions of JavaScript. For more details, see the EcmaScript 6 documentation.

This code in the Pressed event of a Button displays an alert using JavaScript:

Me.ExecuteJavaScript("alert('Hello!');")

This code will select the text in a WebTextField (or WebTextArea):

WebTextField1.ExecuteJavascript("document.getElementById('" + _
  WebTextField1.ControlID + "_inner').select();")

WebButton.GotoURL

GotoURL(URL As String, inNewWindow As Boolean = False)

Opens the passed URL in place of the current web page or downloads a file. If InNewWindow is True, the browser is asked to open the URL in a new window.

If the browser has popup windows disabled and InNewWindow is True, the method silently fails and the page is not shown.

If InNewWindow is False, the running web app is replaced with the specified URL. If you want to display an external web site within your web app, use the WebHTMLViewer control.

Display a web site in a new popup window:

Me.GotoURL("http://www.wikipedia.org", True)

WebButton.Press

Press

Causes the button's Pressed event to execute.

WebButton.SetFocus

SetFocus

Sets the focus to the Control.

This code checks for a required value when a button is pressed:

If UserNameField.Text = "" Then
  MessageBox("Please enter your UserName.")
  UserNameField.SetFocus
  Return
End If

WebButton.UpdateBrowser

UpdateBrowser

Forces the current values of the control to be sent to the browser.

This method is useful when you are computing values in a loop and wish to update the browser immediately rather than wait until the current method ends.

This code iterates through a RowSet of database rows, updates a ProgressBar and then forces the updated ProgressBar to be sent to the browser via UpdateBrowser.

ProgressBar1.Maximum = SalesData.RowCount
For Each row As DatabaseRow in SalesData
 AnalyzeSales(row)
 ProgressBar1.Value = ProgressBar1.Value + 1
 ProgressBar1.UpdateBrowser
Next

Event descriptions

WebButton.Closed

Closed

The control has been removed from the browser either because the page has closed or the control's Close method was called.

WebButton.ContextualMenuSelected

ContextualMenuSelected(hitItem As WebMenuItem)

Called when a contextual menu item is selected. This selected item is contained in hitItem.

This code populates a contextual menu in the Opening event of a WebToolbar:

Var menu As New WebMenuItem

menu.AddMenuItem("One")
menu.AddMenuItem("Two")
menu.AddMenuItem("Three")
Me.ContextualMenu = menu

The menu selection is then handled by the ContextualMenuSelected event when the user right-clicks on the control. For example, it can be of the form:

Select case hitItem.Text
Case "One"
  MessageBox("One")
Case "Two"
  MessageBox("Two")
Case "Three"
  MessageBox("Three")
End Select

WebButton.Hidden

Hidden

The control is about to become no longer visible. This could be because the page is being closed, is being replaced as the foreground page by another page or because the control or a parent control's Visible property has been set to False.

Note

This event is equivalent to the DesktopWindow.Deactivated event in a desktop app.

WebButton.MenuSelected

MenuSelected(item As WebMenuItem)

The WebMenuItem passed was selected from the WebButton's menu.

WebButton.Opening

Opening

The control has been created and the page is opening but has not been sent to the browser yet.

The Opening event handler can be used to initialize non-visual properties and settings for controls.

In most cases, you should use the Shown event to initialize controls.

WebButton.Pressed

Pressed

The WebButton was pressed by the user, the Pressed method was called, if the Default property is True then the Return key was pressed or if the Cancel property is True then the user pressed Command/Control-period.

WebButton.Shown

Shown

The control has appeared on the currently displayed page. This could be because its parent page just finished loading, its parent page has come to the foreground or the control is now visible having been previously invisible because it or its parent control's Visible property has been set to True.

Use the Shown event for initializing your controls or doing anything that would interact with other controls or user interface elements on the web page instead of the Opening event.

Note

This event is the web equivalent to the DesktopWindow.Activated event.

This code in the Shown event of a WebListBox adds 2 rows with 3 columns:

Me.RemoveAllRows
Me.AddRow("Row 1", "Bob", "Roberts")
Me.AddRow("Row 2", "Barb", "Reynolds")

This example sets the text of a label:

If Session.LoggedIn Then
  Me.Text = "Welcome!"
Else
  Me.Text = "Welcome, " + Session.UserName
End If

Notes

When the button is pressed or the Press method is called, the Pressed event is called.

The Default and Cancel properties can only be set to True for a single button each per page at any given moment. When either of these properties is True, the Indicator property is ignored as Default and Cancel buttons have a default indicator.

Sample code

This code changes the Caption of a button between Start/Stop when you click it:

If Button1.Caption = "Start" Then
  Button1.Caption = "Stop"
Else
  Button1.Caption = "Start"
End If

Compatibility

Web projects on all supported operating systems.

See also

WebUIControl parent class; WebSegmentedButton, WebToolbar classes