expressappframework-devexpress-dot-persistent-dot-validation.md
Declares members that custom Validation Rule Sources implement.
Namespace : DevExpress.Persistent.Validation
Assembly : DevExpress.Persistent.Base.v25.2.dll
NuGet Package : DevExpress.Persistent.Base
public interface IRuleSource
Public Interface IRuleSource
Implement the IRuleSource interface in your business class to create a custom Validation Rule Source. Custom Validation Rule Sources allow you to store Validation Rules in the database. We recommend that you use this technique if you need to frequently customize Validation Rules in a deployed application, but you cannot redeploy the application or customize its Application Model.
Note
Persistent validation rules are in action only if the application’s database has been created and initialized. In debug mode, a new XAF application creates its database on the first login attempt (when a user clicks the Log In button for the first time). For these reasons, if you define a persistent validation rule that affects the login form, this rule will not work until you complete the login process at least once.
Refer to the following help topic for information on other techniques to declare Validation Rules: Declare Validation Rules.
The IRuleSource interface declares the following members:
IRuleSource.Name propertyReturns the unique name of the custom Validation Rule Source.IRuleSource.CreateRules methodInstantiates custom Validation Rules.
The Validation Module automatically collects persistent Validation Rule Sources and Rules when you start an application. Persistent Validation Rule Sources and Rules are persistent classes that implement the IRuleSource and IRule interfaces accordingly. Built-in Rule Sources query the database each time before validation occurs. Use the EnableRuntimeRuleCache property to enable Rule caching for all persistent Rule Sources. You can also disable automatic collection of persistent Rules and Rule Sources and add custom proxy Rule Sources with different behavior. To see the example of how to do this, refer to the following property description: EnableRuntimeRuleDiscovery.
The following example demonstrates how to create a custom persistent Validation Rule Source:
using DevExpress.Persistent.Base;
using DevExpress.Persistent.BaseImpl.EF;
using DevExpress.Persistent.Validation;
using System;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Reflection;
namespace YourSolutionName.Module.BusinessObjects;
[DefaultClassOptions]
public class RuleRequiredFieldPersistent : BaseObject, IRuleSource {
public virtual string RuleName { get; set; }
public virtual string CustomMessageTemplate { get; set; }
public virtual bool SkipNullOrEmptyValues { get; set; }
public virtual bool InvertResult { get; set; }
public virtual string ContextIDs { get; set; }
public virtual string Property { get; set; }
public virtual string ObjectType {
get {
if(ObjectTypeCore != null) {
return ObjectTypeCore.FullName;
}
return "";
}
set { ObjectTypeCore = ReflectionHelper.FindType(value); }
}
[NotMapped]
[TypeConverter(typeof(LocalizedClassInfoTypeConverter))]
public virtual Type ObjectTypeCore { get; set; }
#region IRuleSource Members
public ICollection<IRule> CreateRules() {
List<IRule> list = new List<IRule>();
RuleRequiredField rule = new RuleRequiredField();
rule.Properties.SkipNullOrEmptyValues = SkipNullOrEmptyValues;
rule.Properties.Id = ID.ToString();
rule.Properties.InvertResult = InvertResult;
rule.Properties.CustomMessageTemplate = CustomMessageTemplate;
rule.Properties.TargetContextIDs = ContextIDs;
rule.Properties.TargetType = ObjectTypeCore;
if(rule.Properties.TargetType != null) {
foreach(PropertyInfo pi in rule.Properties.TargetType.GetProperties()) {
if(pi.Name == Property) {
rule.Properties.TargetPropertyName = pi.Name;
}
}
}
for(int i = Validator.RuleSet.RegisteredRules.Count - 1; i >= 0; i--) {
if(Validator.RuleSet.RegisteredRules[i].Id == ID.ToString()) {
Validator.RuleSet.RegisteredRules.RemoveAt(i);
}
}
list.Add(rule);
return list;
}
[Browsable(false)]
public string Name {
get { return RuleName; }
}
#endregion
}
// Make sure that you use options.UseChangeTrackingProxies() in your DbContext settings.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Reflection;
using DevExpress.Persistent.Base;
using DevExpress.Persistent.BaseImpl;
using DevExpress.Persistent.Validation;
using DevExpress.Xpo;
// ...
[DefaultClassOptions]
public class RuleRequiredFieldPersistent : BaseObject, IRuleSource {
public RuleRequiredFieldPersistent(Session session) : base(session) { }
public string RuleName {
get { return GetPropertyValue<string>(nameof(RuleName)); }
set { SetPropertyValue(nameof(RuleName), value); }
}
public string CustomMessageTemplate {
get { return GetPropertyValue<string>(nameof(CustomMessageTemplate)); }
set { SetPropertyValue(nameof(CustomMessageTemplate), value); }
}
public bool SkipNullOrEmptyValues {
get { return GetPropertyValue<bool>(nameof(SkipNullOrEmptyValues)); }
set { SetPropertyValue(nameof(SkipNullOrEmptyValues), value); }
}
public string Id {
get { return GetPropertyValue<string>(nameof(Id)); }
set { SetPropertyValue(nameof(Id), value); }
}
public bool InvertResult {
get { return GetPropertyValue<bool>(nameof(InvertResult)); }
set { SetPropertyValue(nameof(InvertResult), value); }
}
public string ContextIDs {
get { return GetPropertyValue<string>(nameof(ContextIDs)); }
set { SetPropertyValue(nameof(ContextIDs), value); }
}
public string Property {
get { return GetPropertyValue<string>(nameof(Property)); }
set { SetPropertyValue(nameof(Property), value); }
}
[Persistent("ObjectType")]
protected string ObjectType {
get {
if (ObjectTypeCore != null) {
return ObjectTypeCore.FullName;
}
return "";
}
set { ObjectTypeCore = ReflectionHelper.FindType(value); }
}
[NonPersistent]
[TypeConverter(typeof(LocalizedClassInfoTypeConverter))]
public Type ObjectTypeCore {
get { return GetPropertyValue<Type>(nameof(ObjectTypeCore)); }
set { SetPropertyValue(nameof(ObjectTypeCore), value); }
}
#region IRuleSource Members
public ICollection<IRule> CreateRules() {
List<IRule> list = new List<IRule>();
RuleRequiredField rule = new RuleRequiredField();
rule.Properties.SkipNullOrEmptyValues = this.SkipNullOrEmptyValues;
rule.Properties.Id = this.Id;
rule.Properties.InvertResult = this.InvertResult;
rule.Properties.CustomMessageTemplate = this.CustomMessageTemplate;
rule.Properties.TargetContextIDs = this.ContextIDs;
rule.Properties.TargetType = this.ObjectTypeCore;
if (rule.Properties.TargetType != null) {
foreach (PropertyInfo pi in rule.Properties.TargetType.GetProperties()) {
if (pi.Name == this.Property) {
rule.Properties.TargetPropertyName = pi.Name;
}
}
}
for (int i = Validator.RuleSet.RegisteredRules.Count - 1; i >= 0; i--) {
if (Validator.RuleSet.RegisteredRules[i].Id == this.Id) {
Validator.RuleSet.RegisteredRules.RemoveAt(i);
}
}
list.Add(rule);
return list;
}
[Browsable(false)]
public string Name {
get { return this.RuleName; }
}
#endregion
}
See Also