*This rule is deprecated, and will eventually be removed.*

Component parameters can only receive query parameter values in routable components with an @page directive.

== Why is this an issue?

https://learn.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.components.supplyparameterfromqueryattribute[SupplyParameterFromQuery] attribute is used to specify that a component parameter of a routable component comes from the https://en.wikipedia.org/wiki/Query_string[query string].

In the case of non-routable components, the `SupplyParameterFromQuery` does not contribute to the functionality, and removing it will not affect the behavior.

== How to fix it

Either make the component routable or remove the `SupplyParameterFromQuery` attribute.

=== Code examples

==== Noncompliant code example

[source,csharp,diff-id=1,diff-type=noncompliant]
----
<h3>Component</h3>

@code {
    [Parameter]
    [SupplyParameterFromQuery]  // Noncompliant
    public bool Param { get; set; }
}
----

==== Compliant solution

[source,csharp,diff-id=1,diff-type=compliant]
----
@page "/component"

<h3>Component</h3>

@code {
    [Parameter]
    [SupplyParameterFromQuery]  // Compliant
    public bool Param { get; set; }
}
----

== Resources

=== Documentation

* Microsoft Learn - https://learn.microsoft.com/en-us/aspnet/core/blazor/fundamentals/routing#query-strings[Query strings]
* Microsoft Learn - https://learn.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.components.supplyparameterfromqueryattribute[SupplyParameterFromQueryAttribute Class]
* Wikipedia - https://en.wikipedia.org/wiki/Query_string[query string]