Class ContainsNoNullItems<T>

A rule which asserts that a collection or a queryable value contains no items that are null.

Inheritance

System.Object

ContainsNoNullItems<T>

Implements

IRuleWithMessage<System.Collections.Generic.IEnumerable<T>>

IRule<System.Collections.Generic.IEnumerable<T>>

IGetsFailureMessage<System.Collections.Generic.IEnumerable<T>>

IRuleWithMessage<System.Linq.IQueryable<T>>

IRule<System.Linq.IQueryable<T>>

IGetsFailureMessage<System.Linq.IQueryable<T>>

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: CSF.Validation.Rules

Assembly: CSF.Validation.StandardRules.dll

Syntax

public class ContainsNoNullItems<T> : IRuleWithMessage<IEnumerable<T>>, IRule<IEnumerable<T>>, IGetsFailureMessage<IEnumerable<T>>, IRuleWithMessage<IQueryable<T>>, IRule<IQueryable<T>>, IGetsFailureMessage<IQueryable<T>>

Type Parameters

Name	Description
T	The type of item contained within the collection.

Remarks

When validating an System.Collections.Generic.IEnumerable<T>, this rule will result in enumerating the enumerable once. However, this rule has an overload specifically for validating an System.Linq.IQueryable<T> which does not enumerate the query. This makes use of the Linq System.Linq.Queryable.All``1(System.Linq.IQueryable{``0},System.Linq.Expressions.Expression{System.Func{``0,System.Boolean}}) extension method, which gives the query provider an opportunity to avoid a full enumeration.

Using this rule to get a failure message does not result in eumerating the collection a second time. The number of null items is recorded and stored in Data, this is then reused when creating the message, if available.

Methods

GetFailureMessageAsync(IEnumerable<T>, ValidationRuleResult, CancellationToken)

Gets the validation failure message for the specified result.

Declaration

public ValueTask<string> GetFailureMessageAsync(IEnumerable<T> value, ValidationRuleResult result, CancellationToken token = default(CancellationToken))

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<T>	value
ValidationRuleResult	result	A validation result, typically indicating failure.
System.Threading.CancellationToken	token	An optional cancellation token.

Returns

Type	Description
System.Threading.Tasks.ValueTask<System.String>	A human-readable message.

GetFailureMessageAsync(IQueryable<T>, ValidationRuleResult, CancellationToken)

Gets the validation failure message for the specified result.

Declaration

public ValueTask<string> GetFailureMessageAsync(IQueryable<T> value, ValidationRuleResult result, CancellationToken token = default(CancellationToken))

Parameters

Type	Name	Description
System.Linq.IQueryable<T>	value
ValidationRuleResult	result	A validation result, typically indicating failure.
System.Threading.CancellationToken	token	An optional cancellation token.

Returns

Type	Description
System.Threading.Tasks.ValueTask<System.String>	A human-readable message.

GetResultAsync(IEnumerable<T>, RuleContext, CancellationToken)

Performs the validation logic asynchronously and returns a task of RuleResult.

Declaration

public ValueTask<RuleResult> GetResultAsync(IEnumerable<T> validated, RuleContext context, CancellationToken token = default(CancellationToken))

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<T>	validated
RuleContext	context	Contextual information about the validation
System.Threading.CancellationToken	token	An object which may be used to cancel the process

Returns

Type	Description
System.Threading.Tasks.ValueTask<RuleResult>	A task which provides a result object, indicating the result of validation

Remarks

This method receives the value to be validated as well as an object which represents the context in which this rule is running. It should return a task of RuleResult.

In order to create the result object, particularly if your rule logic will run synchronously, consider using the CommonResults class via using static CSF.Validation.Rules.CommonResults; in your rule logic. The common results class has helper methods such as PassAsync(IDictionary<String, Object>) and FailAsync(IDictionary<String, Object>) which include optimisations for flyweight task instances that avoid allocating additional resources needlessly.

It is acceptable to throw an uncaught exception from this method, as the validation framework will catch it and automatically convert it into an error result. Generally, developers do not need to manually return a result of outcome Errored manually. This would be appropriate only in an unusual scenario that is considered an error, but which does not involve the throwing of an exception. Error results are generally harder for the consumer to deal with than failure results.

The context parameter may be used, amongst other things, to access 'ancestor' values. However, if this rule only needs access to an immediate parent value then consider using IRule<TValue, TParent> instead.

Exceptions

Type	Condition
System.Exception	This method may raise any exception type

GetResultAsync(IQueryable<T>, RuleContext, CancellationToken)

Performs the validation logic asynchronously and returns a task of RuleResult.

Declaration

public ValueTask<RuleResult> GetResultAsync(IQueryable<T> validated, RuleContext context, CancellationToken token = default(CancellationToken))

Parameters

Type	Name	Description
System.Linq.IQueryable<T>	validated
RuleContext	context	Contextual information about the validation
System.Threading.CancellationToken	token	An object which may be used to cancel the process

Returns

Type	Description
System.Threading.Tasks.ValueTask<RuleResult>	A task which provides a result object, indicating the result of validation

Remarks

This method receives the value to be validated as well as an object which represents the context in which this rule is running. It should return a task of RuleResult.

In order to create the result object, particularly if your rule logic will run synchronously, consider using the CommonResults class via using static CSF.Validation.Rules.CommonResults; in your rule logic. The common results class has helper methods such as PassAsync(IDictionary<String, Object>) and FailAsync(IDictionary<String, Object>) which include optimisations for flyweight task instances that avoid allocating additional resources needlessly.

It is acceptable to throw an uncaught exception from this method, as the validation framework will catch it and automatically convert it into an error result. Generally, developers do not need to manually return a result of outcome Errored manually. This would be appropriate only in an unusual scenario that is considered an error, but which does not involve the throwing of an exception. Error results are generally harder for the consumer to deal with than failure results.

The context parameter may be used, amongst other things, to access 'ancestor' values. However, if this rule only needs access to an immediate parent value then consider using IRule<TValue, TParent> instead.

Exceptions

Type	Condition
System.Exception	This method may raise any exception type

Implements

IRuleWithMessage<TValidated>

IRule<TValidated>

IGetsFailureMessage<TValidated>

IRuleWithMessage<TValidated>

IRule<TValidated>

IGetsFailureMessage<TValidated>