How to store join query data and retrieve using foreach loop from master layout page in asp.net mvc - linq

Question

I am new in asp.net mvc. I am trying to build role wise dynamic menu show in the view page. Each user can have multiple role.
I have a join query like:
My Controller looks like with join query:
var query= (from rMPageMap in db.RoleModulePageMaps
join userRole in db.UserRoleMaps
on rMPageMap.RoleId equals
join roleMaster in db.RoleMasters
on rMPageMap.RoleId equals roleMaster.Id
join modMaster in db.ModuleMaster
on rMPageMap.ModuleId equals modMaster.Id
join sModMaster in db.SubModuleMasters
on rMPageMap.SubModuleId equals sModMaster.Id
join pMaster in db.PageMasters
on rMPageMap.PageId equals pMaster.Id
where (userRole.UserId == appuser.Id &)
select new
{
rMPageMap.RoleId,
rMPageMap.PageMaster.Name,
roleMaster.Id,
roleName = roleMaster.Name,
modId = modMaster.Id,
moduleName = modMaster.Name,
subModuleId = sModMaster.Id,
subModuleName = sModMaster.Name,
pageId = pMaster.Id,
pageName = pMaster.Name,
parentPageId = pMaster.ParentPageId,
rMPageMap.AddData,
rMPageMap.EditData,
rMPageMap.ViewData,
rMPageMap.DeleteData,
rMPageMap.ShowInDashBoard,
rMPageMap.ShowInMenu
});
Session["rolemodulepage"] = query;
I find the values in the session while debugging. but i can not retrieve data from this using foreach loop in layout page.
Here is my view page that i try ro retrieve but does not work.
View Page:
#if (Request.IsAuthenticated)
{
var sessionVar = System.Web.HttpContext.Current.Session["rolemodulepage"];
foreach(var i in sessionVar) // error
{
#i.... // error
}
// So here how to retrieve data from session using foreach loop. I tried but does not work. Pls help. If you have some resource for dynamically mane show in view page pls share with me.
Can anyone explain that how to do it using showing dynamic menu by role based user in master layout page. Wihout login none can enter the site, pls explain with examples so that i can understand. Thanks in advance.

Answer 1

You query is generating a collection of anonymous objects which you cannot access in the view. Create a view model containing the properties you need and project your query into it, for example
public class MenuVM
{
public int RoleId { get; set; }
public string PageMasterName { get; set; }
....
}
and then modify the query to
var query = (from rMPageMap in db.RoleModulePageMaps
....
where (userRole.UserId == appuser.Id &)
select(new MenuVM()
{
RoleId = rMPageMap.RoleId,
PageMasterName = rMPageMap.PageMaster.Name,
....
}).AsEnumerable()
;
and then in the view you can cast the Session value and loop through it
var sessionVar = HttpContext.Current.Session["rolemodulepage"] as IEnumerable<MenuVM>;
if (sessionVar null)
{
foreach(var i in sessionVar)
{
....
However, as this is for generating a menu in a layout, I suggest you create move the code to a child action only method that returns a strongly typed partial view, for example in say CommonController
[ChildActionOnly]
public PartialViewResult Menu()
{
if (!Request.IsAuthenticated)
{
return null;
}
// Check if the session variable exists and if not, generate the query
// and add the result to session
return PartialView("_Menu", query);
}
and the _Menu.cshtml view would be
#model IEnumerable<MenuVM>
#foreach (var i in Model)
{
....
}
and in the layout, use
#{ Html.RenderAction("Menu", "Common"); }
to generate the html for the menu.