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How to filter model data via query string params in asp.net mvc 4 ?

I am creating a view which initially pulls/display all the records on the page and later there are filters(textbox and checkbox) on left where user can filter the results from.
This is my first mvc app, so I have followed the below mentioned approach:
// GET: /Search/
public ActionResult Home(int page = 1)
{
SearchController have a Home method which is default and pushes the data to view to display in grid.
Controls to filter the data is wrapped under:
#using (Html.BeginForm("Home", "Search", FormMethod.Post))
{
for that I have
[HttpPost]
public ActionResult Home(Partner partner)
My QUESTION is :
a) The search needs to be a query string based so that users can share the filtered result so what we be the best way to filter the Model data (partner here) via QS, I know I can either pass the whole model to the ActionResult or I can accept each field name in the AcitionResult.
b) How do you protect the QS params, the best practice ?
Thanks a lot in advance.

First of all, you shouldn't use HttpPost to query filtered data! POST is for performing commands (typically adding new data, but can be used for other functions as well), while GET is used for queries.
Your Home action should be slightly modified:
public ActionResult Home(int page = 1, Person person)
{
// get the initial data - i assume that you using some context for it (you can use service as well)
using(var context = new DbContext())
{
var data = context.... //get the data here
if(person != null)
{
data = data.Where(p => p.id == person.id).ToList(); //filter by id for example
}
//assuming your view gets a List as a model
return View(data)
}
}
I know I can either pass the whole model to the ActionResult or I can accept each field name in the AcitionResult
I wouldn't use your display model as a filter. I would rather create new filter model that will include only the properties that you can filter by them. For example your display model is a list of Person objects and you allow to filter them by name, age, id. I would create something like:
public class PersonFilterModel
{
public int Page //the one from your example
public string Name {get;set;}
public int? age {get;set;}
public int? id {get;set;}
//you can add properties for filter type (starts with, less than, bigger than)
}
so your action will be
public ActionResult Home(PersonFilterModel filter)
If number of filtered properties in not too big you can specify them as action arguments one by one without creating a model:
public ActionResult Home(int page, string name, int? age, int? id)
Regarding the protection of query string: https and ssl are the standard ways that are used in most of the cases.

You could create two methods: One for GET and the other for POST.
[HttpPost]
public ActionResult Home(Partner partner)
[ActionName("Home")]
[HttpGet]
public ActionResult GetHome(Partner partner)
When you searching and passing parameters in the query string, it will go to the GetHome method, but the URL will still be the same.

I would like to first answer question b. I am assuming you want to prevent users from using a query string that will filter data in a way that shows data they should not be seeing. I don't think you need to secure the query string. Security should be handled server side. You shouldn't put anything in a query string that needs to be secured, for example a password.
Providing the ability to filter based on a query string is pretty powerful, especially if you do this in a dynamic way. I recently did this in a framework I wrote called Dynamic MVC (http://dynamicmvc.com). If you interested in using that you can install through nuget. It would provide the functionality your asking for with almost no coding on your part. However, if your not interested in Dynamic MVC you could take a look at how I did it on CodePlex (https://dynamicmvc.codeplex.com)
If you just want a quick summary, here is how I did it:
Parse the query string for any relevant properties for your model. You could use reflection to get the property names.
Once you have the relevant properties you can use dynamic linq to filter the data with a linq to entities query.

What is the most standard way to persist data between MVC views?

I'm creating a system using ASP.NET MVC for filling out online job applications. It's really just an experiment to familiarize myself with the MVC framework. I'm definitely not a security expert so I just wanted to get some advice here since this web app will be dealing with sensitive information.
The system has a wizard-like set of views. You go from one view to the next filling out the relevant information until the end when you finally submit it.
Each job application is stored in the database with a GUID primary key. Right now I am simply storing that GUID in a hidden field in the view of each page. This makes it easy to update the model in the controller like so:
[HttpPost]
public ActionResult ExampleAction(FormCollection formValues)
{
Guid appId = new Guid(Request.Form["ModelId"]); // the GUID stored in the hidden field
ExampleModel example = db.Entities.Single(e => e.ModelId == appId);
UpdateModel(example, formValues);
db.SaveChanges();
return RedirectToAction("ExampleAction2", new { appId = appId.ToString() });
}
I know this is not secure because anyone with any kind of development experience knows you can edit the values of hidden fields in any browser's developer tools. So what's the recommended way to securely get the same results?

You should store it in the Session object. That way, you can call it at anytime from anywhere and it will never display on any of your views.
The doc: http://msdn.microsoft.com/en-us/library/ms178581.aspx

I know this has been answered, just for interest sake I want to leave another option. How you could go about it is parsing the information you get from the first view as a JSON string that you can store in a cookie and then later serialize it when you need it.
This is asuming that the information is safe to store client side. Otherwise it could be an encrypted cookie I suppose. This would address the concerns for cloud computing and load balancers etc.

Why not post to each step instead of using RedirectToAction? That way you can create a model that contains each step.. for example:
class JobApplicationViewModel
{
public Guid ApplicationGuid { get; set; }
public StepOne Step1 { get; set; }
public StepTwo Step2 { get; set; }
public int CurrentStep { get; set; }
}
The step 1 view can post to step 2.. for example:
[HttpPost]
public ViewResult StepTwo(JobApplicationViewModel viewModel)
{
ServiceLayer.Update(viewModel);
return View(viewModel);
}
Then, the StepTwo view posts to StepThree, StepThree posts to Step4, etc. This makes sense logically, as you're only allowing people to get to any step beyond step 1 by posting the form.

Reusing a view in another view with parameters in ASP.NET MVC

Being rather new to ASP.NET MVC, I am already seeing some benefits of it for code reuse and maintainability. When asking a previous question on routing, I had another idea for my example, but unsure how to implement it.
Question: How can I reuse my issue view and controller in separate pages, as well as having parameters for certain things (like how many issues to display)?
Example: Say in my web application I want to show a list of issues. These issues are grouped by projects. So if you go to www.example.com/projectname/issues, you would see a list of issues for that project, and if you went to www.example.com/issues, you would see all issues for all projects. What I would like to do is that if you go to www.example.com/projectname, you would see some info about that project, including the last 10 issues submitted.
How can I reuse this issue code? I see I have the option for Partial View, but when I implemented it, I was unsure how to route any code to it. In Web Forms, you could make a ASP.net control, set some parameters in the code behind, and then embed this control elsewhere.
Some of the examples I have found so far either lack a complete implementation (goiing beyond just adding some HTMl in other pages), look like older MVC code that doesn't seem to work for me in ASP.NET MVC 3, and lack allowing me to set paramaters and showing this type of reuse.
My terminology may not be entirely correct here. If anything, I am trying to find the best (read MVC) way to replicate something like ASP.net Web Forms User Controls. As in, reusing my 'issues' code (HTML and C#) on both a 'master' issues list, as well as an issues 'widget' if you will

Skip the temptation write code in the view that goes out and accesses data on it's own. That includes using built-in functions like RenderAction. Even though RenderAction "goes back" to execute another controller it doesn't mean the view isn't taking an action on its own, which arguably breaks the MVC approach where views are supposed to do nothing and the model is supposed to contain everything the view needs.
Instead what you could do is send back a model for your issue list page(s) which contains a property containing the issues list:
public class IssueListModel {
public List<Issue> Issues { get; set; }
}
Populate it in your issue list action:
public ActionResult IssueList(string projectName) // projectName may be null
{
var issueListModel = new IssueListModel();
issueListModel.Issues = SomeRepository.GetIssues(projectName); // whatever you need to send...
return View(issueListModel);
}
Then on your list pages you could loop through it:
#foreach (var issue in Model.Issues) {
<div>#issue.IssueName</div>
}
Or you could send the Issues collection down to a partial view:
#Html.RenderPartial("IssueList", Model.Issues)
You can type your partial view to expect List as the model:
#model List<MyProject.Models.Issue>
... and then loop through it in the partial view, this time doing a foreach on the model itself:
#foreach (var issue in Model) {
<div>#issue.IssueName</div>
}
Then what you can do is make a separate model for your project detail view which also contains a property containing Issues:
public class ProjectDetailModel {
public Project Project { get; set; }
public List<Issue> Issues { get; set; }
public string Whatever { get; set; }
}
In the controller you can populate this List using the same function that you would populate in your lists controller:
public ActionResult ProjectDetail(string projectName)
{
var projectDetailModel = new ProjectDetailModel();
projectDetailModel.Issues = SomeRepository.GetIssues(projectName, 10); // whatever you need to send
return View(projectDetailModel);
}
Then you can re-use the same exact partial view on your ProjectDetail view:
#Html.RenderPartial("IssueList", Model.Issues)
A long answer but I hope this is what you were looking for!

If you want to re-use presentation logic only, you can use partial view. If you want to re-use also controller's logic, you have to use child action combined with partial view.
Create a controller
public class IssuesController : Controller
{
[ChildActionOnly]
public PartialViewResult List(string projectName, int issueCount = 0)
{
IEnumerable<Issue> issueList = new List<Issue>();
// Here load appropriate issues into issueList
return PartialView(issueList);
}
}
Do not forget also to create appropriate partial view named List within the folder Issues.
Finally use this line within your project view
#{ Html.RenderAction("List", "Issues", new { projectName = "Px", issueCount = 10 } ); }
and this line within your issue list view
#{ Html.RenderAction("List", "Issues", new { projectName = "Px" } ); }

In your controller method return the view as named rather than just View()
ie...
public ViewResult IssueView1()
{ return View("Issue");}
public ViewResult IssueView2()
{return View("Issue");}

MVC3 Partial Views

Still Learning MVC3, EF. For now I am connecting to MySql but I believe that will not be relevant. For simplicity, I decided to use one database for my test application and I have included a category to differentiate the data. For eg I have a news, events,info and pages categories. Now when it comes to listing contents in views for example at the homepage, I want to list latest 5 news items(news category), latest 5 events(events category), welcome text(info category). i have been able to create partialViews to list these at the different sections of the homepage. But I feel am doing this wrongly since in each of these PartialViews I am querying the same table over and over and just filtering with where cat=....in the LINQ query.
Can you please confirm if that should be the practice or there is a better way to do this.

You could do the following:
Controller:
public ActionResult Home()
{
IEnumerable<MyDateRecords> myData = LinqQueryToGetAllTheDataUnFiltered();
ViewData.Model = new MyViewData { MyData = myData; }
return View();
}
ViewModel class:
public class MyViewData
{
List<MyDataRecords> MyData { get; set; }
List<MyDataRecords> News { get { return MyData.Where(m => m.Category = "News"); } }
List<MyDataRecords> Events { get { return MyData.Where(m => m.Category = "Events"); } }
}
View:
#model MyViewModel
#Html.Partial("NewsPartial", Model.News)
#Html.Partial("EventsPartial", Model.Events)
Partial:
#model IEnumerable<MyDataRecord>
This way we only queried for the data once and just passed a different set to each partial

For an uncomplicated way of presenting this type of data, what you are doing is fine. You should look at the OutputCacheAttribute for any PartialView Method you use on your Controller.

This is pretty inefficient. But it's good that you noticed this because querying that database is often the bottleneck in any given request.
For starters you should retrieve that data into a dictionary or model and then pass it to the partial views to render similar to what Bassam outlined. Ideally, this should be taken care of in the Controller to stick to the MVC paradigm and then passed to the main view, which would then pass the appropriate data to the partial views.
Once you get more advanced/familiar with ASP.NET MVC, you can start looking into caching. I'd stay away from caching for right now since it get somewhat tricky if you have data that is rapidly changing since you need to start worrying about updating/synchronizing/etc.

MVC Dynamic Views From Url Slug

I am building my first .NET MVC web application and loving the simplicity and flexibility. I have however come to my first stumbling block.
I have a list of items and if you are not logged in you will see a preview link I would like the link to direct to something like below:
/preview/unique-slug
The view should then allow me to display the contents from the database (essentially a details page)
I am not sure how to approach this nor what I should be Google'ing as the results I got were poor.
Any pointers please?

This is the way I've done this in the past:
You need to store in the database a column with the slug that each item is referred to by. Then, create a route like the following:
routes.MapRoute("PreviewLink",
"/preview/{slug}",
new { controller = "Preview", action = "Details" }
);
So this will call the Details method on the PreviewController like so:
class PreviewController : Controller
{
public ActionResult Details(string slug)
{
var model = db.GetItemBySlug(slug);
return View("Details", model);
}
}
Basically, you'll get the slug as a string in your action method, query the database for the item with the corresponding slug, and display it. Essentially, we just replace an integer id with a string slug.
Hopefully that clears things up for you!