Using Action Return Values in Javascript

This is really basic code, and if you do improve on it, please contribute back!

Add this to your controller:

protected override void InvokeMethod(MethodInfo method, IRequest request, IDictionary actionArgs)
{
	ParameterInfo[] parameters = method.GetParameters();

	object[] methodArgs = BuildMethodArguments(parameters, request, actionArgs);

	object result = method.Invoke (this, methodArgs);

	bool isAjaxAction = method.GetCustomAttributes(typeof(AjaxActionAttribute), false).Length > 0;

	if(result != null)
	{
		if (isAjaxAction)
		{
		    if (typeof(bool).IsAssignableFrom(result.GetType()))
                    {
                        RenderText(
                            (bool)result
                                ? Newtonsoft.Json.JavaScriptConvert.True
                                : Newtonsoft.Json.JavaScriptConvert.False
                        );
                    }
                    else
                    {
                        RenderText(Newtonsoft.Json.JavaScriptConvert.SerializeObject(result));
                    }
		}
		else
		{
			RenderText(result.ToString());
		}
	}
}

Then create an action method which returns something:

[AjaxAction]
public Post AjaxWithParams(int number, string text)
{
	Post post = new Post();

	post.Body = number.ToString();
	post.Subject = text;

	return post;
}

Now create a new Helper:

public class MyAjaxHelper : AbstractHelper
{
	public string GetRemoteValue(string controller, string action, string callback, IDictionary parameters)
	{
		return GetRemoteValue("", controller, action, callback, parameters);
	}

	public string GetRemoteValue(string area, string controller, string action, string callback, IDictionary parameters)
	{
		string url = (area == "" ? "" : "/" + area) + "/" + controller + "/" + action + ".rails";

		return "new Ajax.Request('" + url + "', { parameters:'" + BuildQueryString(parameters) + "', onSuccess: function(r) { " + callback + "(eval('(' + r.responseText + ')')); }});";
	}
}

DON'T FORGET: ensure you set up your controller to use this helper! Now, from some view:

<script type="text/javascript" src="/MonoRail/Files/AjaxScripts.rails"></script>

<script type="text/javascript">

$MyAjaxHelper.GetRemoteValue("area", "thread", "AjaxWithParams", "callback", "%{number=5, text='howdy'}")

function callback(serverObject) {
	alert(serverObject.Body);
}

</script>

You call GetRemoteValue with the area (optional), controller, action, name of a JS callback function, and Dictionary of parameters. The callback function must have one parameter, and this is the object returned from the server. In this case we'll get a Post object back and we alert the Body property on it.

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Using Action Return Values in Javascript