66 lines
1.5 KiB
Plaintext
66 lines
1.5 KiB
Plaintext
== Why is this an issue?
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A writable collection property can be replaced by a completely different collection. Making it ``++readonly++`` prevents that while still allowing individual members to be set. If you want to allow the replacement of the whole collection the recommended pattern is to implement a method to remove all the elements (e.g. ``++System.Collections.List<T>.Clear++``) and a method to populate the collection (e.g. ``++System.Collections.List<T>.AddRange++``).
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This rule raises an issue when an externally visible writable property is of a type that implements ``++System.Collections.ICollection++`` or ``++System.Collections.Generic.ICollection<T>++``.
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=== Noncompliant code example
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[source,text]
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----
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using System;
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using System.Collections;
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namespace MyLibrary
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{
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public class Foo
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{
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List<string> strings;
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public List<string> SomeStrings
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{
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get { return strings; }
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set { strings = value; } // Noncompliant
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}
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}
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}
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----
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=== Compliant solution
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[source,text]
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----
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using System;
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using System.Collections;
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namespace MyLibrary
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{
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public class Foo
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{
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List<string> strings;
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public readonly List<string> SomeStrings
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{
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get { return strings; }
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}
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}
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}
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----
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=== Exceptions
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This rule does not raise issues for
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* ``++string++``, ``++Array++`` and ``++PermissionSet,++``
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* properties marked as ``++DataMemberAttribute++``
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* classes marked as ``++Serializable++``
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* properties overriding a base class member
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* properties implementing interface
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