How do i use Blazor components in the code?

Question

I'm trying to accomplish something like the code below but I can't seem to figure out how to do it.

@page "/"

<div>@test</div>
@code {
[Parameter]
public string Animal { get; set; }

private BaseComponent test { get; set; }

protected override async Task OnInitializedAsync()
{
    switch (Animal)
    {
        case "Cat": test = <Cat>Fluffy</Cat>; break;
        case "Dog": test = <Dog>Woff</Dog>; break;
        default: test = <p>None</p>
    }
}

I also want to be able to put components in a dictionary like new Dictionary<string, BaseComponent> { {"cat", <Cat>test</Cat> }}

any ideas?

Answer 1

It is possible with RenderFragments:

private Dictionary<string, RenderFragment> switcher 
  = new Dictionary<string, RenderFragment>(StringComparer.CurrentCultureIgnoreCase)
{
    {  "cat" , __builder => { <Cat> It's a Cat </Cat> } },
    {  "dog" , __builder => { <Dog> It's a Dog </Dog> } },

};

and then outside of @code,

@switcher["Cat"]

---

But if this is the best solution depends very much on the exact use-case, and how much flexibility is desired in using the <Animal> tags.

You could for instance replace the above with a <ShowAnimal Animal="Cat" /> component and implement that with a (big) switch statement in the markup section.

Answer 2

A dictionary of render fragments:

@_content

@code {

    [Parameter]
    public string Animal { get; set; }

    RenderFragment _content => Animal switch
    {
        "Cat" => @:@{ <Cat>Fluffy</Cat> } 
,
        "Dog" => @:@{ <Dog>Woff</Dog> } 
,
           _  => @:@{ <p>None</p> } 
    };

}

Note:

Switch comma's currently must to be on the next line due to a parsing bug.