How to link to Home page from sub folder? - asp.net-core-2.0

I have the following in views/page2/index.cshtml:
#Html.ActionLink("Continue...", "Home");
I'd like the above to link to the root Home controller's view. What I get now is localhost/page2/home/ instead of localhost/.
Any ideas how to use the correct path?

In that case you do not need to use the html helper to generate the link. Use pure html.
Home
This link will link to the root of your web application.

The prototype for the ActionLink looks like this:
public Microsoft.AspNetCore.Html.IHtmlContent ActionLink (
string linkText,
string actionName,
string controllerName,
string protocol,
string hostname,
string fragment,
object routeValues,
object htmlAttributes);
So when you call #Html.ActionLink("Continue...", "Home"); you are passing in the linkText and the actionName. Since this is all the router has to work with, it assumes the actionName you want (Home) is within the same Controller as the current page.
In order to tell the router that you want to switch to another Controller, you need to pass that Controller name in as well.
#Html.ActionLink("Link Text", "Action", "Controller");
I'm going to assume that when you're passing in Home you actually wanted to reach the Index action from the Home controller. If so, this would look like this:
#Html.ActionLink("Continue...", "Index", "Home");

Related

Pass value from one controller to another

I have two controllers. One is login.js and the another one is home.js. I want to redirect to home controller from login controller with a value. To redirect to home controller, i wrote,
response.redirect('/home');
But, i cannot pass value here. When rendering a view with a value,
data = {'value':'hello'};
response.render('view_login',data);
I want to do the same thing. I can pass value while rendering to the view but not when changing controller. Can i do this?
response.redirect('/home',{data: data});
you can use query parameters for this.
When you are redirecting your home page or any other controller then you can write like this
res.redirect(/<some controller>?data=<some data>)
and in that controller where you want to use this value..you can write like this
function login(req,res){
var data = req.query.data;
}

MVC Action Link Issue

I have come across what appears to be an inconsistency in MVC 5 regarding the Html.Actionlink. In different cshtml files I can use the same code, but the url target that is generated is different.
For example, this line of code:
<td>#Html.ActionLink(item.Description, "Edit", new { item.ParentTableID }) </td>
generates this URL
localhost\MyControllerClass\Edit?ParentTableID=35
That then properly calls the ActionView method Edit and feeds the parameter with 35 as expected.
However, in another cshtml file, this line
<td>#Html.ActionLink("Edit", "EditChild", new { id = f.ApplicationTableFieldID})</td>
produces this url
localhost/MyControllerClass/Edit/7
and when it hits the EditChild Action View, the parameter is null.
I have seen this now a couple of times and not yet been able to understand what makes the difference. But I need the first result.
Thanks.
Ensure that your ID parameters are named correctly in both your Action method and your ActionLink Html helper. The visual difference comes from MVC default routing and how it can take a parameter named ID and put it in the URL without the query string (? followed by stuff)
If your action method looks like this
public ActionResult EditChild(int ParentTableID){}
Then you will need to have your ID parameter named ParentTableID when you pass it back in your URL
<td>#Html.ActionLink("Edit", "EditChild", new { ParentTableID = f.ApplicationTableFieldID})</td>
Should now produce the following URL
localhost\MyControllerClass\EditChild?ParentTableID=3

Can MVC Custom Error pages retain Route Values?

The MVC project that I am currently working on uses Regions so that we can localise pages etc.
I have spotted a problem with our Error page. We have turned the custom error pages on in the web.config file. If we are on a page lets say : /IT/News/Index and we get an error, when it redirects it will go to /Error and there will be no routevalue attached to it.
Is there away to ensure that the langauge routevalue is retained by the Error page?
I have searched around and cannot find a solution at the moment and was wondering if anyone else could help or point me in the right direction?
Hope that this all makes sense. Any help is much appreciated.
If you're getting physically redirected to /Error then it's not because of the MVC HandleErrorAttribute. It's probably due to your Web.Config having system.web/customErrors defined for error handling. Using the HandleErrorAttribute causes it to inject a specific view instead of the view you would have normally returned but does not redirect you to a different action by default. The problem is when redirected because of customErrors, there is no inherant information available to tell you where they came from. But using HandleErrorAttribute DOES cause some info to be populated for you. Specifically it creates a HandleErrorInfo to use as a view model and passes that to the view you specify. For example, here's one that is reigstered in the /App_Start/FilterConfig.cs file.
public class FilterConfig
{
public static void RegisterFilters(GlobalFilterCollection filters)
{
filters.Add(new HandleErrorAttribute {View = "Error"});
}
}
When you redirect to an error View using the HandleErrorAttribute, certain information is populated for you. The HandleErrorInfo view model will contain the ControllerName of the original controller requested, and the ActionName of the original action. Also, the ViewData and the TempData from the original request will be copied into the ViewData and Temp data for the request to the Error view. With that information it should have what you need. Be aware that not all errors happen inside of an Action however, and exceptions that don't happen in an action will not be caught by the HandleErrorAttribute. So you'll still need to use something like customErrors (or system.webServer/httpErrors if you're doing it inside of IIS7+) to handle exceptions that occur elsewhere in your app.
Here's a link to the HandleErrorAttribute file on CodePlex in case you're wondering what it does. HandleErrorAttribute.cs
I'm not sure if this solution meets you requirements. You can override in your base controller OnException and then redirect to a specific page.
protected override void OnException(ExceptionContext filterContext)
{
string controller = filterContext.RouteData.Values["controller"].ToString();
string action = filterContext.RouteData.Values["action"].ToString();
//get other stuff from routing
//here you can do redirect or other stuff
//if handled exception
//filterContext.ExceptionHandled = true;
base.OnException(filterContext);
}
It depends how you're getting to the error pages, really. If you're using an ActionFilter-based method to catch exceptions, then you can get route values from the context that gets passed into the OnException method. If you're using a redirect from a catch block, then you can push the relevant information into TempData or pass it directly as a parameter, depending on how you're doing that redirect.
You can add a custom HandleErrorAttribute or use a base controller to be inherited by all your controllers. Either way, you need to get the RouteData object, like this
var routeData = filterContext.RouteData;
with that object, you can get all the route values accordingly to your needs. Check the object definition in MSDN site for more detail
Say you have the following route
routes.MapRoute(
"Language", // Route name
"{language}/{controller}/{action}/{id}", // URL with parameters
new { language = "en", controller = "Sites", action = "Index", id = UrlParameter.Optional } // Parameter default
Then routeData.Values.Keys will tell you the name of the parameter and routeData.Values.Values the value itself
Then, wherever you handle the exception, you can store the route data in a TempData variable, like this
TempData["RouteData"]
And after that, it will be available on your error page
#model System.Web.Mvc.HandleErrorInfo
#{
ViewBag.Title = "Error";
}
<h2>
Sorry, an error occurred while processing your request.
</h2>
#TempData["RouteData"];

How to create a RenderURL during action phase in a portlet?

In the method processAction(ActionRequest request, ActionResponse response), I insert a record into database and get the ID and then
I want to redirect to the view page of this record. So I need to create a RenderURL with a parameter value for that ID.
ActionResponse doesn't provide method to create a renderURL. Some codes in Liferay do similar things like:
create renderURL before accessing the actionURL
pass the renderURL as a parameter in the actionURL
However, at that time, I don't know the value of ID.
Other codes also use new PortletURLImpl() directly. My portlet cannot see that class.
Other codes also use new PortletURLImpl() directly. My portlet cannot see that class.
Because this class is in portal-impl.jar and also it is not recommended to use classes from this jar. Starting from Liferay 6.1, you won't be able to build your portlet from plugins-sdk if you classes point to portal-impl.jar.
Now to answer your question:
Any jsp is rendered by the render method or doView method (if using liferay's MVCPortlet) and this method would be called as part of the normal life-cycle of portlets.
Here are the steps you would need to take:
set a render parameter (using response.setRenderParameter() method) in your `processAction' method at the last which would be available in your render method, as follows:
actionResponse.setRenderParameter("myID", 1201);
Just for info: After using setRenderParameter you cannot use sendRedirect method
fetch this "myID" in your render method as you fetch any other request parameter:
//assuming your ID is a long
long myUserName = ParamUtil.getLong(renderRequest, "myID");
or
String strMyID = renderRequest.getParameter("myID");
long myID = Long.parseLong(strMyID);
After this, just use
include(renderPage, renderRequest, renderResponse);
were renderPage is nothing but a string containing the path to your jsp within docroot like /html/yourportlet/view.jsp
Just as an afterthought:
If you are using a Liferay IDE, then you can try creating a simple portlet project with MVCPortlet and then look at the generated portlet.xml's <init-param>
So basically you need to pass information from action-phase to render-phase, the development guide is a good place for explaining this in detail.
That's it.
Hope this helps.
Let me know if you have any confusion regarding this.
In action phase do the following:
ThemeDisplay themeDisplay = (ThemeDisplay)request.getAttribute (WebKeys.THEME_DISPLAY);
PortletURL url = PortletURLFactoryUtil.create(request, this.getPortletName(), themeDisplay.getPlid(), PortletRequest.RENDER_PHASE);
For example, if you want to redirect to the login page and back, you can do the following:
response.sendRedirect("/c/portal/login?redirect=" + HttpUtil.encodeURL(url.toString()));
Definitely you can add or copy the parameters as required.
Instead of creating the renderURL you can include the view page include(viewTemplate,actionRequest,actionResponse). Or if you want to sent any parameter any want's to get it in doView then use actionResponse.setParameter(name,value) method
I create a RenderURL with a place holder as parameter value, like this:
<portlet:renderURL var="redirect">
<portlet:param name="ID" value="__ID__" />
</portlet:renderURL>`
In processAction:
String redirect = redirectParam.replace("__ID__", "123213");
actionResponse.sendRedirect(redirect) ;

How to render a template by name?

I am trying to get my head around ServiceStack self-hosted app and the new API.
Adding two views of the same name in separate folders results in an error at startup. Is this not allowed?
Foo\
Index.cshtml
Bar\
Index.cshtml
Is there a way to specify a template via a decorator on a method or directly as a return value? I know about the convention of naming views after DTOs. I prefer to be more explicit or follow a convention closer to Sinatra/Express.
return Render(typeof(Views.Foo.Index), new { Name = "Nelly" });
The ServiceStack's Razor Rockstars website which holds the documentation for Razor support in ServiceStack lists some options for selecting a different template:
If it doesn't follow the convention (i.e. Request or Response DTO name) then you can dynamically specify which view or layout template gets used by returning a decorated HttpResult like:
return new HttpResult(dto) {
View = {viewName},
Template = {layoutName},
};
If you're using a static view (i.e. service always uses the same view) then you can specify what view to use by decorating it with the [DefaultView] attribute
[DefaultView("Rockstars")]
public object Get(Rockstars request) {
...
return responseDto;
}
In either case, if you want it strong-typed you can use something like typeof(RequestDto).Name.
View names must be unique
Unlike MVC, heirachy's does not influence view selection in ServiceStack and because each View Page (i.e. razor pages in the /Views folder) must be unique, you're free to lay them out in any flat or nested folder structure you wish.

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