How to pass rendering parameters for a static controller rendering

Question

There is need to load a controller rendering from the Razor view.
I'm doing it this way:

@Html.Sitecore().ControllerRendering("Captcha", "GoogleReCaptcha", new { RedisCacheKeyPrefix = "scans_", GoogleReCaptchaValidationMessage = "Please fill up the captcha" })

Here Captcha is the controller name, GoogleReCaptcha is the action name.

RedisCacheKeyPrefix & GoogleReCaptchaValidationMessage are the rendering parameters, i.e the exact field names of the rendering parameter template.

I'm assigning the default values here.

In the code, reading the values:

string prefix= RenderingContext.Current.Rendering.Parameters["RedisCacheKeyPrefix"]  
string message= RenderingContext.Current.Rendering.Parameters["GoogleReCaptchaValidationMessage"]

But they are always null.

What is the correct way to pass the rendering parameters in this case.

Answer 1

The naming of the 3rd parameter of @Html.Sitecore().ControllerRendering method is a bit unfortunate. It's called parameters, while in my opinion it should be called properties.

The reason for that is one can access what is passed via this parameter using

RenderingContext.Current.Rendering.Properties[...]

So in your example:

@Html.Sitecore().ControllerRendering("Captcha", "GoogleReCaptcha", new { RedisCacheKeyPrefix = "scans_", GoogleReCaptchaValidationMessage = "Please fill up the captcha" })

can be accessed using

string prefix = RenderingContext.Current.Rendering.Properties["RedisCacheKeyPrefix"]  
string message = RenderingContext.Current.Rendering.Properties["GoogleReCaptchaValidationMessage"]

Answer 2

I suggest that you create a setting item somewhere in Sitecore that contain's the two properties / fields, and then set the setting item as a DataSource:

@Html.Sitecore().ControllerRendering("Captcha", "GoogleReCaptcha", new
{
    DataSource = "{sitecore-id-of-setting-item}"
})

Something like this. Then your content is editable and you can request the DataSource item (with the two fields) in your controller as usual.