Interface IConfiguresValidator<TValidated>

A builder service which may be used to configure a validator as it is being built.

Namespace: CSF.Validation.ValidatorBuilding

Assembly: CSF.Validation.Abstractions.dll

Syntax

public interface IConfiguresValidator<TValidated>

Type Parameters

Name	Description
TValidated	The validated object type.

Methods

AddBaseRules<TBase, TBuilder>()

Adds/imports rules from an object that implements IBuildsValidator<TValidated>. These rules should be for validation of a type from which TValidated derives.

Declaration

IConfiguresValidator<TValidated> AddBaseRules<TBase, TBuilder>()
    where TBuilder : IBuildsValidator<TBase>

Returns

Type	Description
IConfiguresValidator<TValidated>	A reference to the same builder object, enabling chaining of calls if desired.

Type Parameters

Name	Description
TBase	The base type, for which validation rules are to be imported. The type TValidated must derive from the type specified in this generic type parameter.
TBuilder	The type of a class implementing IBuildsValidator<TValidated>, specifying how a validator for the base type should be built.

Remarks

This allows composition of validators and use of rules declared to validate a base type, reusing validation rules across differing validation scenarios. All of the rules specified in the selected builder-type will be imported and added to the current validator.

Exceptions

Type	Condition
System.InvalidCastException	If the type specified as TBase is not an ancestor type to TValidated.

AddRule<TRule>(Action<IConfiguresRule<TRule>>)

Adds a validation rule to validate the validated object instance. The rule type must be a class that implements IRule<TValidated> for the same (or a compatible contravariant) generic type TValidated.

Declaration

IConfiguresValidator<TValidated> AddRule<TRule>(Action<IConfiguresRule<TRule>> ruleDefinition = null)
    where TRule : IRule<TValidated>

Parameters

Type	Name	Description
System.Action<IConfiguresRule<TRule>>	ruleDefinition	An optional action which defines & configures the validation rule.

Returns

Type	Description
IConfiguresValidator<TValidated>	A reference to the same builder object, enabling chaining of calls if desired.

Type Parameters

Name	Description
TRule	The concrete type of the validation rule.

AddRules<TBuilder>()

Adds/imports rules from an object that implements IBuildsValidator<TValidated>.

Declaration

IConfiguresValidator<TValidated> AddRules<TBuilder>()
    where TBuilder : IBuildsValidator<TValidated>

Returns

Type	Description
IConfiguresValidator<TValidated>	A reference to the same builder object, enabling chaining of calls if desired.

Type Parameters

Name	Description
TBuilder	The type of a class implementing IBuildsValidator<TValidated>, specifying how a validator should be built.

Remarks

This allows composition of validators and reuse of validation rules across differing validation scenarios. All of the rules specified in the selected builder-type will be imported and added to the current validator.

ForMember<TValue>(Expression<Func<TValidated, TValue>>, Action<IConfiguresValueAccessor<TValidated, TValue>>)

Allows addition of validation which will work upon the value of a specific member of the validated object.

Declaration

IConfiguresValidator<TValidated> ForMember<TValue>(Expression<Func<TValidated, TValue>> memberAccessor, Action<IConfiguresValueAccessor<TValidated, TValue>> valueConfig)

Parameters

Type	Name	Description
System.Linq.Expressions.Expression<System.Func<TValidated, TValue>>	memberAccessor	An expression which describes the accessor for the member.
System.Action<IConfiguresValueAccessor<TValidated, TValue>>	valueConfig	Configuration which indicates what validation will be performed upon the member's value.

Returns

Type	Description
IConfiguresValidator<TValidated>	A reference to the same builder object, enabling chaining of calls if desired.

Type Parameters

Name	Description
TValue	The type (property/field/method-return-type) of the member which is being validated.

Remarks

Most commonly the member is a property, but it may also be a field or parameterless method (which has a non-void return value).

When it is possible to describe a validated value by a simple member access then this mechanism is preferred over ForValue<TValue>(Func<TValidated, TValue>, Action<IConfiguresValueAccessor<TValidated, TValue>>) because the member name will form a part of the validation rule's identifier.

Exceptions

Type	Condition
System.ArgumentNullException	If either memberAccessor or valueConfig are null.

ForMemberItems<TValue>(Expression<Func<TValidated, IEnumerable<TValue>>>, Action<IConfiguresValueAccessor<TValidated, TValue>>)

Allows addition of validation which will work upon each of the items exposed by a specific member of the validated object, where that member's type implements System.Collections.Generic.IEnumerable<T>.

Declaration

IConfiguresValidator<TValidated> ForMemberItems<TValue>(Expression<Func<TValidated, IEnumerable<TValue>>> memberAccessor, Action<IConfiguresValueAccessor<TValidated, TValue>> valueConfig)

Parameters

Type	Name	Description
System.Linq.Expressions.Expression<System.Func<TValidated, System.Collections.Generic.IEnumerable<TValue>>>	memberAccessor	An expression which describes the accessor for the collection member.
System.Action<IConfiguresValueAccessor<TValidated, TValue>>	valueConfig	Configuration which indicates what validation will be performed upon the collection items.

Returns

Type	Description
IConfiguresValidator<TValidated>	A reference to the same builder object, enabling chaining of calls if desired.

Type Parameters

Name	Description
TValue	The type of the items within the collection which shall be validated, where the type (property/field/method-return-type) of the member implements System.Collections.Generic.IEnumerable<T> of this generic type.

Remarks

Most commonly the member is a property, but it may also be a field or parameterless method (which has a non-void return value).

When it is possible to describe the collection which should have its items validated by using a simple member access then this mechanism is preferred over ForValues<TValue>(Func<TValidated, IEnumerable<TValue>>, Action<IConfiguresValueAccessor<TValidated, TValue>>) because the member name will form a part of the validation rule's identifier.

Exceptions

Type	Condition
System.ArgumentNullException	If either memberAccessor or valueConfig are null.

ForValue<TValue>(Func<TValidated, TValue>, Action<IConfiguresValueAccessor<TValidated, TValue>>)

Allows addition of validation which will work upon an arbitrary value derived from the validated object.

Declaration

IConfiguresValidator<TValidated> ForValue<TValue>(Func<TValidated, TValue> valueAccessor, Action<IConfiguresValueAccessor<TValidated, TValue>> valueConfig)

Parameters

Type	Name	Description
System.Func<TValidated, TValue>	valueAccessor	A function which gets the value to be validated.
System.Action<IConfiguresValueAccessor<TValidated, TValue>>	valueConfig	Configuration which indicates what validation will be performed upon the value.

Returns

Type	Description
IConfiguresValidator<TValidated>	A reference to the same builder object, enabling chaining of calls if desired.

Type Parameters

Name	Description
TValue	The type of the value which is to be validated.

Remarks

When it is possible to describe/acces the derived value by a simple member access then please prefer ForMember<TValue>(Expression<Func<TValidated, TValue>>, Action<IConfiguresValueAccessor<TValidated, TValue>>) over this method.

Exceptions

Type	Condition
System.ArgumentNullException	If either valueAccessor or valueConfig are null.

ForValues<TValue>(Func<TValidated, IEnumerable<TValue>>, Action<IConfiguresValueAccessor<TValidated, TValue>>)

Allows addition of validation which will work upon each of the items exposed by an arbitrary collection, derived from the validated object, which implements System.Collections.Generic.IEnumerable<T>.

Declaration

IConfiguresValidator<TValidated> ForValues<TValue>(Func<TValidated, IEnumerable<TValue>> valuesAccessor, Action<IConfiguresValueAccessor<TValidated, TValue>> valueConfig)

Parameters

Type	Name	Description
System.Func<TValidated, System.Collections.Generic.IEnumerable<TValue>>	valuesAccessor	A function which gets the collection, for which its items should be validated.
System.Action<IConfiguresValueAccessor<TValidated, TValue>>	valueConfig	Configuration which indicates what validation will be performed upon the collection items.

Returns

Type	Description
IConfiguresValidator<TValidated>	A reference to the same builder object, enabling chaining of calls if desired.

Type Parameters

Name	Description
TValue	The type of the items within the collection which shall be validated, where the collection itself implements System.Collections.Generic.IEnumerable<T> of this generic type.

Remarks

When it is possible to describe/access the collection by a simple member access then please prefer ForMemberItems<TValue>(Expression<Func<TValidated, IEnumerable<TValue>>>, Action<IConfiguresValueAccessor<TValidated, TValue>>) over this method.

Exceptions

Type	Condition
System.ArgumentNullException	If either valuesAccessor or valueConfig are null.

UseObjectIdentity(Func<TValidated, Object>)

Specifies an accessor function which should be used to get the identity of the validated object.

Declaration

IConfiguresValidator<TValidated> UseObjectIdentity(Func<TValidated, object> identityAccessor)

Parameters

Type	Name	Description
System.Func<TValidated, System.Object>	identityAccessor	The accessor function.

Returns

Type	Description
IConfiguresValidator<TValidated>	A reference to the same builder object, enabling chaining of calls if desired.

Remarks

Object identities are useful & important when validating complex object models which include object graphs (tree-structures) of related/connected objects. This is particularly true where collections are child objects are involved. The identity is used to differentiate object instances. For example, so that the validation rule results may be matched back to the object to which they relate.

Examples

For example, if validating an instance of the following object:

using System;
using System.Collections.Generic;
public class HumanBeing
{
public Guid Identity { get; set; } = new Guid();
public string Name { get; set; }
public List<HumanBeing> Children { get; } = new List<HumanBeing>();
}

Without any kind of identity, if we had a validation rule that validated the Name property is not null or whitespace-only, then what if more than one child failed this same rule? In our feedback (for example some user interface), how would we indicate which children failed the validation and which children did not.

By using (for example) the Identity property to uniquely identity each instance of HumanBeing we will recieve the related identities back with the validation rule results, allowing us to associate the results back to the appropriate object within the object graph.

ValidateAsAncestor(Int32)

Configures the current value to be validated in the same manner as an ancestor value which already has validation configuration.

Declaration

IConfiguresValidator<TValidated> ValidateAsAncestor(int depth)

Parameters

Type	Name	Description
System.Int32	depth	The ancestor number to use when validating the current value.

Returns

Type	Description
IConfiguresValidator<TValidated>	A reference to the same builder object, enabling chaining of calls if desired.

Remarks

If this method is used then the current value will be configured for recursive (or re-entrant) validation. It will be converted as a ManifestItem that is recursive rather than a normal value.

The numeric value of depth must be a positive integer & indicates the level of ancestor value is used to provide the recursive validation. For example a value of 1 indicates that the immediate parent value should be used as the wrapped value for the recursive manifest value. A value of 2 would indicate the grandparent value.

When recursive validation is configured, no other methods upon this builder may be called. Doing so will raise an exception. The validation of the current value will be treated in the same way as the indicated ancestor value.

WhenValueIs<TDerived>(Action<IConfiguresValidator<TDerived>>)

Adds validation configuration for polymorphic validatation when the runtime type of the validated value is TDerived.

Declaration

IConfiguresValidator<TValidated> WhenValueIs<TDerived>(Action<IConfiguresValidator<TDerived>> derivedConfig)
    where TDerived : TValidated

Parameters

Type	Name	Description
System.Action<IConfiguresValidator<TDerived>>	derivedConfig	Configuration which indicates what validation will be performed upon the value if its runtime type is TDerived.

Returns

Type	Description
IConfiguresValidator<TValidated>	A reference to the same builder object, enabling chaining of calls if desired.

Type Parameters

Name	Description
TDerived	The derived (child) type to be configured for validation in this polymorphic validation configuration.

Remarks

Where the current validator configuration works to validate an object of type TValidated, the value being validated might be a derived type of TValidated at runtime. Polymorphic validation allows a developer to specify how a derived type should be validated, if that is the runtime type of the value to be validated.

This method may be used multiple times, each time for a different type that is derived from TValidated.