TagHelper for passing route values as part of a link

Question

When specifying asp-controller and asp-action on a link, what's the syntax for also passing an id attribute?

E.g. If I wanted to link to the edit URL for a given object, the required URL would be /user/edit/5 for example.

Is there a method to achieve this using TagHelpers, or do we still have to fall back to @Html.ActionLink()?

Bioecology

Answer 1

You can use the attribute prefix asp-route- to prefix your route variable names.

Example: <a asp-action="Edit" asp-route-id="10" asp-route-foo="bar">Edit</a>

Wreckage

I couldn't get this to work, because my "asp-route-foobar" didn't match my route: "routes.MapRoute("yearNoCombo", template: "{controller=Home}/{action=Index}/{foobar?}/{whatever1}/{whatever2}"); - the route-names must match. HTH others. – Regular

In addition to the above comment you do need to ensure that your routes are setup correctly to avoid the route bit appearing as a parameter in the HTML Either using MapRoute or route annotations on your methods – Accretion

@Wreckage can I pass object in asp-route dynamic – Riddell

@Riddell This can be done with a Dictionary<string, string> passed to the all-route-data parameter. – Nonexistence

Answer 2

I'd like to suggest a combination of the other two answers, but with a bit of extra clarification.

You will use an attribute prefix asp-route-{name} where {name} is the name of the route parameter you want to use. In other words, if the number 5 in your route is passed into the controller as an ID value, you could have:

<a asp-controller="User" asp-action="Edit" asp-route-id="@item.ID">Edit</a>

or if the parameter you wanted to pass to the route was item.UserName then

<a asp-controller="User" asp-action="Edit" asp-route-username="@item.UserName">Edit</a>

And if you had both parameters then

<a asp-controller="User" asp-action="Edit" asp-route-id="@item.Id" asp-route-username="@item.UserName">Edit</a>

Fully

This definitely made more sense to me than the others. Can you also have multiple asp-route-{parameter name} in the same <a></a> ? This helped my issue with it Not binding properly trying to send a foreign key CompanyId back as it was using Id and placing it in the Order primary key Id instead. – Debbee

Yes, you can. According to davepaquette.com/archive/2015/06/01/… You can specify values for as many parameters as you need using attributes with the asp-route- prefix. I don't think you can have two parameters with the same name - there is a feature request/issue about that here github.com/aspnet/Mvc/issues/4560 – Fully

So if I read that right, currently there is a way to pass lists only in the action helper method and not in the anchor tag helpers. – Debbee

I've updated my answer to show passing two parameters in the anchor taghelper. Is that better? – Fully

Didn't really need to. I of course didn't know of the terminology used in your links when I was seeking answers to my question about passing lists back. – Debbee

Worked for me. I implemented for pagination – Candida

Worked for me after banging my head trying to figure it out. This is great. – Schacker

Answer 3

you can pass custom ID using below code:

<a asp-controller="User" asp-action="Edit" asp-route-id="@item.ID">Edit</a>

Boresome

Answer 4

I would suggest one more way for Razor view to use model value using @Html.actionlink in jsp

var URLvalue='@Html.ActionLink("UserString", "action", new { routeValueName1 = "__value1__", routeValueName2="__value2__" }, htmlAttributes: new { @class = "btn btn-default", @role = "button" })'
     .replace('__value1__', Model.somevalue).replace('__value2__',  Model.somevalue);

you can use URLvalue where ever you want to in jsp or jquery.

Placebo