Class
WebContainer
Description
A WebContainer is a way to create a group of controls that are treated as a single control. A WebContainer is a great way to simplify complex web page layouts. In addition, with a WebContainer, you can create reusable controls to include on multiple web pages or on other web containers.
Properties
Name |
Type |
Read-Only |
Shared |
---|---|---|---|
✓ |
|||
✓ |
|||
✓ |
|||
✓ |
|||
✓ |
|||
✓ |
|||
Methods
Name |
Parameters |
Returns |
Shared |
---|---|---|---|
Child As WebControl |
|||
Index As Integer |
|||
View As WebView, X As Integer, Y As Integer, Width As Integer, Height As Integer |
|||
Script As String |
|||
control As WebUIControl |
|||
parentControl As WebUIControl, displaySide As WebContainer.DisplaySides = WebContainer.DisplaySides.Bottom |
|||
Events
Name |
Parameters |
Returns |
---|---|---|
hitItem As WebMenuItem |
||
Enumerations
WebContainer.DisplaySides
DisplaySides
Specifies where the popover will display relative to the control its popping over.
Enum |
Description |
---|---|
Bottom |
Below the parent control. |
Left |
To the left of the parent control. |
Top |
Above the parent control. |
Right |
To the right of the parent control. |
WebContainer.ScrollDirections
ScrollDirections
The various directions that can be assigned for scrolling.
Enum |
Description |
---|---|
None |
The WebContainer cannot be scrolled. |
Horizontal |
The WebContainer can only be scrolled horizontally. |
Vertical |
The WebContainer can only be scrolled vertically. |
Both |
The WebContainer can be scrolled both horizontally and vertically. |
Property descriptions
WebContainer.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
WebContainer.ControlCount
ControlCount As Integer
The number of controls on the WebContainer.
This property is read-only.
WebContainer.ControlID
ControlID As String
Identifies the control on a per session basis.
This property is read-only.
WebContainer.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
WebContainer.Height
Height As Integer
The height (in pixels) of the control.
WebContainer.Indicator
Indicator As WebUIControl.Indicators
The color scheme for the control.
WebContainer.LayoutDirection
LayoutDirection As WebView.LayoutDirections
The direction in which WebContainer will flow when added at runtime to a layout whose LayoutType is set to Flex.
WebContainer.LayoutType
LayoutType As WebView.LayoutTypes
The type of layout dictates whether controls are positioned at fixed locations or can move to accommodate changes to the bounds of the WebView, in the latter case, only for WebContainer that are added at runtime to a layout whose type is set to Flex.
WebContainer.Left
Left As Integer
The position of the left side of the WebUIControl in pixels, relative to the web page.
WebContainer.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.
WebContainer.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).
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.
WebContainer.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.
WebContainer.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.
WebContainer.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.
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.
WebContainer.Name
Name As String
The name of the control.
This property is read-only.
WebContainer.PanelIndex
PanelIndex As Integer
If the control has been placed on a WebTabPanel or WebPagePanel control, this is the panel (page/tab) that the control is on. If the control is not on a panel, it returns -1.
The first panel is numbered zero. If the control has been placed on a panel of a WebTabPanel or WebPagePanel control, it returns the panel number. If the control is not on a WebPagePanel or WebTabPanel, it returns -1. If you change the PanelIndex to a nonexistent panel, the control will disappear until you give it a PanelIndex value that corresponds to a panel that exists.
If you are looking to change the currently selected panel (page/tab), use SelectedPanelIndex.
This code displays the panel index of the control that is on the page.
MessageBox(Me.SelectedPanelIndex.ToString)
WebContainer.Page
Page As WebPage
Identifies the web page that contains the control.
This property is read-only.
WebContainer.Parent
Parent As WebView
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.
WebContainer.ScrollDirection
ScrollDirection As ScrollDirections
The direction or directions in which the user can scroll the WebContainer assuming that the bounds of the instance are smaller than bounds of the WebContainer itself.
This property is read-only.
WebContainer.TabIndex
TabIndex As Integer
The WebContainer'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
WebContainer.Tooltip
Tooltip As WebToolTip
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"
WebContainer.Top
Top As Integer
The top of the control in local coordinates relative to the web page.
WebContainer.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
WebContainer.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
WebContainer.AddControl
AddControl(Child As WebControl)
Adds the passed Control to the WebView.
This code adds a WebTextField to the page:
Var tf As New WebTextField
tf.Left = 100
tf.Top = 50
tf.Enabled = True
Self.AddControl(tf)
WebContainer.Close
Close
This removes the control from the page, but only if the control is part of a Control Set or is a WebContainer. Otherwise it does not do anything.
In general, if you want to add or remove controls from pages, use a WebContainer.
WebContainer.ControlAt
ControlAt(Index As Integer) As WebControl
Returns the WebControl at the index passed.
WebContainer.Controls
Controls As Iterable
Allows you to iterate through the controls on the layout.
Note
This does not include non-control object instances. For that, use the Objects method.
WebContainer.EmbedWithin
EmbedWithin(webView As WebView, Width As Integer, Height As Integer)
Embeds the WebView in the current page without drawing the window frame, title bar, title bar widgets, grow handle, and so forth. Use this set of parameters with webpages whose LayoutType is Flex.
EmbedWithin(webView As WebView, X As Integer, Y As Integer, Width As Integer, Height As Integer)
Embeds the WebView in the current page without drawing the window frame, title bar, title bar widgets, grow handle, and so forth. Use this set of parameters with webpages whose LayoutType is Fixed.
The X and Y parameters determine the location of the top-left corner, relative to the containing page. The parameters Width and Height determine the size of the embedded view.
You can use EmbedWithin in to dynamically add controls to a page. Add the control (or controls) you want to add to a WebContainer and then use EmbedWithin to add the container to the page at runtime.
The locking properties of the WebContainer are not carried over when you use EmbedWithin. Instead, set these values accordingly before calling EmbedWithin. For example:
Var c As New MyContainer
c.LockLeft = True
c.LockTop = True
c.LockRight = True
c.EmbedWithin(Self, 0, 0, c.Width, c.Height)
This code adds a WebContainer, called LoginContainer, to a web page at runtime:
Var login As New LoginContainer
login.LockLeft = True
login.LockTop = True
login.EmbedWithin(Self, 0, 0, login.Width, login.Height)
WebContainer.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();")
WebContainer.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)
WebContainer.LastControlIndex
LastControlIndex As Integer
The index of the last WebControl on the WebView.
WebContainer.Objects
Objects As Iterable
Allows you to iterate through all the non-control object instances on the container.
Note
This does not include controls. For that, use the Controls method.
WebContainer.RemoveControl
RemoveControl(control As WebUIControl)
Removes the control from the WebContainer.
WebContainer.SetFocus
SetFocus
Sets the focus to the Control.
This code checks for a required value when a button is pressed:
If UserNameField.Text.IsEmpty Then
MessageBox("Please enter your UserName.")
UserNameField.SetFocus
Return
End If
WebContainer.ShowPopover
ShowPopover(parentControl As WebUIControl, displaySide As WebContainer.DisplaySides = WebContainer.DisplaySides.Bottom)
Displays the container as a popover next to the parentControl based upon the parameters passed.
This example from a button's Pressed event displays the container named MyPopover below (the default) the button:
Var c As New MyPopover
c.ShowPopover(Me)
WebContainer.Style
Style As WebStyle
Style(Assigns value 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
WebContainer.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.MaximumValue = SalesData.RowCount
For Each row As DatabaseRow in SalesData
AnalyzeSales(row)
ProgressBar1.Value = ProgressBar1.Value + 1
ProgressBar1.UpdateBrowser
Next
Event descriptions
WebContainer.Closed
Closed
The control has been removed from the browser either because the page has closed or the control's Close method was called.
WebContainer.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
WebContainer.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.
The event is similar to the Window.Deactivate event in a desktop app.
WebContainer.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.
WebContainer.Overflowed
Overflowed(width As Integer, height As Integer)
The area (in pixels) by which WebContainer have overflowed the bounds of a WebView whose LayoutType is set to WebView.LayoutTypes.
WebContainer.Resized
Resized
The WebView has been resized either because the user resized the browser window or the WebView was resized at runtime via code.
WebContainer.Scrolled
Scrolled
The WebContainer has been scrolled.
WebContainer.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
This class is useful for creating reusable sets of controls. Itʼs also useful for creating scrollable views. You can create a scrollable view by creating a WebContainer and then after placing it on a webpage or other WebContainer, make the WebContainer on the page smaller than it would normally appear. The ScrollDirection property controls which directions the user can scroll the WebContainer if any.
You can also use a WebContainer to center your page contents in the browser window. To do so, put all your controls on a WebContainer and then add the WebContainer to a WebPage. For the properties of the WebContainer, select LockVertical and LockHorizontal to ensure that the WebContainer always stays centered in the page displayed in the browser.
WebContainers can only contain controls that are subclasses of WebUIControl.
Sample code
This code adds a WebContainer, called LoginContainer, to a web page at runtime:
Var login As New LoginContainer
login.EmbedWithin(Self, 100, 100, login.Width, login.Height)
Compatibility
Web projects on all supported operating systems.
See also
WebView parent class; WebUIControl, WebPage, WebView