ObjectFormatter.Format(String, Object, EmptyEntriesMode) Method

Replaces format items in the specified string with the values of the specified object’s properties. Allows you to specify the EmptyEntriesMode mode of processing the passed string.

Namespace: DevExpress.Persistent.Base

Assembly: DevExpress.ExpressApp.v23.2.dll

NuGet Package: DevExpress.ExpressApp

Declaration

C#

public static string Format(
    string format,
    object obj,
    EmptyEntriesMode mode
)

VB.NET

Public Shared Function Format(
    format As String,
    obj As Object,
    mode As EmptyEntriesMode
) As String

Parameters

Name	Type	Description
format	String	A string that contains zero or more format items.
obj	Object	An object whose property values are used in the formatting of the passed string.
mode	EmptyEntriesMode	An EmptyEntriesMode enumeration value that specifies the mode of processing the passed string.

Returns

Type	Description
String	A string in which the format items have been replaced by the string representations of the specified object’s property values.

Remarks

The Format method treats all the format items in the passed string as the property names of the passed object. It replaces all the format items in the passed string with the corresponding property values of the passed object.

This method can be used to create calculated properties in persistent classes. The following code snippet illustrates how to define the non-persistent read-only FullName property. This property’s value is calculated from the FirstName and LastName properties using the Format method.

C# (EF Core)

using DevExpress.Persistent.Base;
using DevExpress.Persistent.BaseImpl.EF;
using System.ComponentModel.DataAnnotations;

//...

[DefaultClassOptions]
public class Contact : BaseObject {
    public virtual string FirstName { get; set; }
    public virtual string LastName { get; set; }
    public string FullName {
        get {
            return ObjectFormatter.Format(
                "{LastName}, {FirstName}", this,
                EmptyEntriesMode.RemoveDelimiterWhenEntryIsEmpty );
        }
    }
}

// Make sure that you use options.UseChangeTrackingProxies() in your DbContext settings.

C# (XPO)

using DevExpress.Xpo;
using DevExpress.Persistent.Base;
using DevExpress.Persistent.BaseImpl;

//...

[DefaultClassOptions]
public class Contact : BaseObject {
    public Contact(Session session) : base(session) { }

    public string FirstName {
        get { return GetPropertyValue<string>(nameof(FirstName)); }
        set { SetPropertyValue<string>(nameof(FirstName), value); }
    }

    public string LastName {
        get { return GetPropertyValue<string>(nameof(LastName)); }
        set { SetPropertyValue<string>(nameof(LastName), value); }
    }

    public string FullName {
        get {
            return ObjectFormatter.Format(
                "{LastName}, {FirstName}", this,
                EmptyEntriesMode.RemoveDelimiterWhenEntryIsEmpty );
        }
    }
}

VB.NET (XPO)

Imports DevExpress.Xpo
Imports DevExpress.Persistent.Base
Imports DevExpress.Persistent.BaseImpl

'...

<DefaultClassOptions> _
Public Class Contact
  Inherits BaseObject
    Public Sub New(ByVal session As Session)
        MyBase.New(session)
    End Sub

    Public Property FirstName() As String
        Get
            Return GetPropertyValue(Of String)(NameOf(FirstName))
        End Get
        Set(ByVal value As String)
            SetPropertyValue(Of String)(NameOf(FirstName), value)
        End Set
    End Property

    Public Property LastName() As String
        Get
            Return GetPropertyValue(Of String)(NameOf(LastName))
        End Get
        Set(ByVal value As String)
            SetPropertyValue(Of String)(NameOf(LastName), value)
        End Set
    End Property

    Public ReadOnly Property FullName() As String
        Get
            Return ObjectFormatter.Format( _
            "{LastName}, {FirstName}", Me, _
            EmptyEntriesMode.RemoveDelimiterWhenEntryIsEmpty )
        End Get
    End Property
End Class

The following image illustrates a Detail View for the implemented Contact class.

If custom processing of the strings passed to the Format method is required, handle the ObjectFormatter.CustomFormatObject event.