AddStatementToConstructorFromTemplate Xaml Mapping Action

Description

Adds an statement to the constructor of the current XAML page. The statement is specified using a code template as with the ReplaceWithTemplate Code Action.

Properties

Property	​Usage	​Description
CodeTemplate	​Required / Content property	A C# code template for the statement to be added .

Predefined template variables

Variable name	​Description
​$propertyValue	the value of the Xaml property being mapped as a C# identifier​
​$propertyValueAsString	the value of the Xaml property being mapped as a C# string literal​
​$elementName	​the name of the current element as a C# identifier

Example

Example #1 Mapping for BackKeyPress

Say that we want to create a mapping that moves the PhoneApplicationPage.BackKeyPress event (https://msdn.microsoft.com/en-US/library/windows/apps/xaml/microsoft.phone.controls.phoneapplicationpage.backkeypress(v=vs.105).aspx) to the Windows.Phone.UI.Input.HardwareButtons.BackPressed event which can only be set in code. We can write the following code:

<MapUnit xmlns='clr-namespace:Mobilize.Mappers.Extensibility.Core;assembly=Mobilize.ExtensibleMappers'
         xmlns:xmap='clr-namespace:Mobilize.XamlMappers;assembly=Mobilize.XamlMapper'
         xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml' >
    <MapUnit.Elements>
        <xmap:XamlElementMapper ElementName="PhoneApplicationPage" ElementNamespace="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone">
            <xmap:XamlElementMapper.Maps>

              ...

              <xmap:XamlMap Kind="Property" PropertyName="BackKeyPress" >
                <xmap:XamlMap.Action>
                  <xmap:ActionSequence>
                    <xmap:AddStatementToConstructorFromTemplate>
                      <![CDATA[ Windows.Phone.UI.Input.HardwareButtons.BackPressed += $propertyValue;  ]]>
                    </xmap:AddStatementToConstructorFromTemplate>
                  <xmap:ChangeEventHandlerEventArgsType NewEventArgsTypeName="Windows.Phone.UI.Input.BackPressedEventArgs" />
                  <xmap:ReplaceEventHandlerParameterMember Position="1">
                    <xmap:ParameterMemberReplacement From="Cancel" To="Handled"/>
                  </xmap:ReplaceEventHandlerParameterMember>
                  </xmap:ActionSequence>
                </xmap:XamlMap.Action>
              </xmap:XamlMap>

            </xmap:XamlElementMapper.Maps>
            <xmap:XamlElementMapper.ReferencedPackages>
                <x:String>CommonAttributesToRemove</x:String>
                <x:String>CommonPostMappingActions</x:String>
            </xmap:XamlElementMapper.ReferencedPackages>
        </xmap:XamlElementMapper>
    </MapUnit.Elements>
</MapUnit>

Using this mapping will take the value of the BackKeyPress property and used to apply the code template to generate an statement.

For example for :

<phone:PhoneApplicationPage
    x:Class="PhoneApp1.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    shell:SystemTray.IsVisible="True"
    BackKeyPress="PhoneApplicationPage_BackKeyPress"
    >

...

</phone:PhoneApplicationPage>

This will generate the following change:

public MainPage()
{
   InitializeComponent();
   Windows.Phone.UI.Input.HardwareButtons.BackPressed += PhoneApplicationPage_BackKeyPress;
   // Sample code to localize the ApplicationBar
   //BuildLocalizedApplicationBar();
}

Example #2 Using the element name

The element name can be used in the code template. For example, say that we want set the value of a property in the constructor instead of using a Xaml element.

For example:

-- Windows Phone Silverlight --

<cntrls:DatePicker x:Name="datePicker" Value="1/1/2001" />

We can write a mapping for this property as follows:

<MapUnit xmlns='clr-namespace:Mobilize.Mappers.Extensibility.Core;assembly=Mobilize.ExtensibleMappers'
         xmlns:xmap='clr-namespace:Mobilize.XamlMappers;assembly=Mobilize.XamlMapper'
         xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml' >
    <MapUnit.Elements>
        <xmap:XamlElementMapper ElementName="DatePicker"
                                ElementNamespace="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls.Toolkit">
            <xmap:XamlElementMapper.Maps>
              ...

              <xmap:XamlMap Kind="Property" PropertyName="Value" >
                <xmap:XamlMap.Action>
                  <xmap:ActionSequence>
                    <xmap:AddStatementToConstructorFromTemplate>
                      <![CDATA[ $elementName.Date = System.DateTimeOffset.Parse($propertyValueAsString); ]]>
                    </xmap:AddStatementToConstructorFromTemplate>
                    <xmap:RemoveAttribute/>
                  </xmap:ActionSequence>
                </xmap:XamlMap.Action>
              </xmap:XamlMap>

            </xmap:XamlElementMapper.Maps>
        </xmap:XamlElementMapper>
    </MapUnit.Elements>
</MapUnit>

Now the constructor will have the following code:

--- UWP ---

...
public Form1()
{
     datePicker.Date = System.DateTimeOffset.Parse("1/1/2001");
}

Notes

• The statement must be a valid C# statement (see )
• The statement is added at the end of the constructor
• The '$elementName' template variable has a valid value if the current element has the x:Name property.
• The '$propertyValue' template variable has a valid value if the value of the current property can be represented as a C# indentifier (see https://msdn.microsoft.com/en-us/library/aa664670.aspx)