Best Practices For Using MVC With A Dictionary-like Model?
Feb 11, 2011
I'm about to begin an ASP.NET MVC project and I'm not sure how to approach an aspect of the design. Basically, there is a user site and an admin site. In the admin sites, administartors design a form and send an e-mail link out to a handful of people. When the users click on the link, they are sent to the form.
Essentially what I'm wondering is what are the best practices when the model resembles looks more like a dictionary than a table?
By picking MVC for developing our new site, I find myself in the midst of "best practices" being developed around me in apparent real time. Two weeks ago, NerdDinner was my guide but with the development of MVC 2, even it seems outdated. It's an thrilling experience and I feel privileged to be in close contact with intelligent programmers daily. Right now I've stumbled upon an issue I can't seem to get a straight answer on - from all the blogs anyway - and I'd like to get some insight from the community. It's about Editing (read: Edit action). The bulk of material out there, tutorials and blogs, deal with creating and view the model.
So while this question may not spell out a question, I hope to get some discussion going, contributing to my decision about the path of development I'm to take. My model represents a user with several fields like name, address and email. All the names, in fact, on field each for first name, last name and middle name. The Details view displays all these fields but you can change only one set of fields at a time, for instance, your names. The user expands a form while the other fields are still visible above and below. So the form that is posted back contains a subset of the fields representing the model. While this is appealing to us and our layout concerns, for various reasons, it is to be shunned by serious MVC-developers.
I've been reading about some patterns and best practices and it seems that this is not in key with the paradigm of viewmodel == view. Or have I got it wrong? Anyway, NerdDinner dictates using FormCollection och UpdateModel. All the null fields are happily ignored. Since then, the MVC-community has abandoned this approach to such a degree that a bug in MVC 2 was not discovered. UpdateModel does not work without a complete model in your formcollection. The view model pattern receiving most praise seems to be Dedicated view model that contains a custom view model entity and is the only one that my design issue could be made compatible with.
It entails a tedious amount of mapping, albeit lightened by the use of AutoMapper and the ideas of Jimmy Bogard, that may or may not be worthwhile. He also proposes a 1:1 relationship between view and view model. In keeping with these design paradigms, I am to create a view and associated view for each of my expanding sets of fields. The view models would each be nearly identical, differing only in the fields which are read-only, the views also containing much repeated markup. This seems absurd to me. In future I may want to be able to display two, more or all sets of fields open simultaneously.
Given the following view model and action using the DefaultModelBinder, it seems to ignore the dictionary, but bind all other properties correctly. Am I missing something here? Looking at the MVC source code this seems legit.
public class SomeViewModel { public SomeViewModel() {[code].....
i having error throw on View page and i think i am passing wrong type.
The model item passed into the dictionary is of type 'System.Collections.Generic.List1[App.Domain.Model.Interface.IPerson]' but this dictionary requires a model item of type 'System.Collections.Generic.IEnumerable1[App.Domain.Service.PersonService]'.
MyService looks like this....
namespace App.Domain.Service { public class PersonService : IPersonService [code].....
I have a asp.net mvc view which is strongly typed view and i have a controller which returnsthe ilist user based on the id provided. I am getting the following above error:
The model item passed into the dictionary is of type 'System.Collections.Generic.List`1[Data.User]', but this dictionary requires a model item of type 'Data.User'.
I am new on MVC and i trying to learn it. My project its about a e-store...
But i got this error:he model item passed into the dictionary is of type 'baraMjukis.ViewModels.ProductViewModel', but this dictionary requires a model item of type 'System.Collections.Generic.IEnumerable`1[baraMjukis.ViewModels.ProductViewModel]'. And here are my code:
Calling Index view is giving me this very very annoying error . Can anybody tell me what to do about it
Error:The model item passed into the dictionary is of type 'System.Collections.Generic.List1[MvcApplication13.Models.Groups]', but this dictionary requires a model item of type 'MvcApplication13.Helpers.PaginatedList1[MvcApplication13.Models.Groups]'.
public ActionResult Index(int? page) { const int pageSize = 10; [code].....
I have a class that maintains a static dictionary of cached lookup results from my domain controller - users' given names and e-mails.My code looks something like:
private static Dictionary<string, string> emailCache = new Dictionary<string, string>(); protected string GetUserEmail(string accountName) { if (emailCache.ContainsKey(accountName)) { return(emailCache[accountName]); } lock(/* something */) { if (emailCache.ContainsKey(accountName)) [code]...
I have a web application where users can upload the photo. I do have a windows service running which takes the uploaded photo and crops it to different sizes. This runs in a specified interval. Photo will be visible to the user once after it's cropped. So once user uploads the photo and photo cropper has not yet run, they wont be able to see the photo. Due to this behaviour user thinks that there was some error uploading the photo and they will upload it again and again.
where the photocropper runs immediately when the user uploads the photos which is queued.
I'm very new to MVC (just started 2 days ago), and I would like to know what the best practice is for outputing HTML.
I have a model named Tools.cs which contains the code below. It uses a stored procedure to return a recordset of menu items, and another to return a second level of menus for each first level menu. In another function, I then loop through the recordset and generate the HTML code to display the menu in a string, which is then returned.
I then have a controller MenuController.cs which calls the GetMenu method and puts the returned HTML string in the ViewData["RightMenu"].
I then have a view which displays the result.
My question is: would it be better practice to return my datareader to the controller into ViewData["RightMenu"], and then loop through it and construct my HTML in the View instead?How would I get that to work with that second level of menus?[Code]....
For WPF, there's the Microsoft Patterns & Practices's Prism project.
Prism provides guidance designed to you more easily design and build rich, flexible, and easy-to-maintain Windows Presentation Foundation (WPF) desktop applications, Silverlight Rich Internet Applications (RIAs), and Windows Phone 7 applications I was wondering whether a similar project (reference implementation) intended for software developers building WCF applications exists.
In our main internal project (a .Net WinForms rich client app), we don't talk directly with the database but instead fetch and update data with ASP.Net web-services that we also control. Our current setup is giving us some bottlenecks. For a new smallish project, we want to try WCF. Objective question: Where do I find a not-too-basic WCF reference project?
In my experience building web applications, I've always used a n-tier approach. A DAL that gets data from the db and populates the objects, and BLL that gets objects from the DAL and performs any business logic required on them, and the website that gets it's display data from the BLL.I've recently started learning LINQ, and most of the examples show the queries occurring right from the Web Application code-behinds(it's possible that I've only seen overly simplified examples). In the n-tier architectures, this was always seen as a big no-no.I'm a bit unsure of how to architect a new Web Application.
All too often I find myself being required to design pages that flow through a series of steps. 1) Select from a set of options. Submit.2) Populate a page with results. Make changes. Submit.3) Do something based on the previous results. Submit.4) Confirm previous actions. Submit.5) Goto 1.An ecommerce site with shopping cart would be a textbook example of this.Now, there are any number of ways to deal with this. My question is, what is the recommended way to do it in asp.net? In PHP or ISAPI I would just use standard html controls, get the post data and do stuff with it, each on a different page
We are working on a project which has lots of routes that can be changed on-the-fly or new routes can be added dynamically. What are the best practices about managing lots of routes and adding routes on-the-fly without recompiling? Reading-Writing from-to database or from Xml Document in Application_Start?
Here is the code of my Repository class:You see, I use singleton here. Also you see, there is a data context as class variable of Repository class.The main reason to use singleton here is a wish to avoid using 'using(NorthwindEntities context = new NorthwindEntities())' in every function.
[Code]....
This Repository is used in ASP.NET application. So only instance of NorthwindEntities (context) is used everywhere and that's why I never dispose it.So my question is: Won't this code cause connections to the DB that are not closed?
Possible Duplicate: Best practices for exception management in JAVA or C# I am using class libraries and I try to put maximum code in class libraries so that it can be reused in other projects.Please advice me where I should put try catch blocks in class library functions or in front end forms (aspx pages) ?
I'm building an MVC 2 RTM app, and I want to be able to share my model across applications. I'd *like* to be able to implement it like:ASP.NET MVC2 app (holds Views and Controllers)Class library to hold Model(s)WCF app to handle the data transactions with the models via different data stores across apps I had the MVC app working fine, but I wanted to abstract the data stuff and be able to work with the model across apps through the WCF site, so I created a class library project and moved all of the Models classes into that and set-up a WCF app, then added project references to the MVC and WCF apps that point at the class library. The idea was I can create services that take and return objects from the model via method calls across apps. It appears that everything's wired up correctly in the MVC project, so I'm passing the objects stored in the Models class library between controllers and views and everythig is compiling just fine, but for some reason the data is not being passed back from the views to the controller on POST -- all of the properties in the classes are null or empty.
When I debug the app, I can see that the values are stored in the model data dictionary but not the model object itself. What am I doing wrong? Am I on the wrong path, or missing something obvious (to some)?
I made a few changes to the DB in SQL server management studio then right clicked on the .edmx doc to get it to update. That seemed to work fine but when i compiled the app everything that referenced the EF seems to be broken.The Error list now contains the below error for all classes that used it.
The type or namespace name '' could not be found (are you missing a using directive or an assembly reference?)
I have an issue of static variable in an asp.net application. Let's say I have a server with 8 CPUs running windows 2008 R2 hosting an asp.net webbsite, nothing fancy here, no funny configuration.
Is the following statement true? at any single time, there's one and only one process is running and accepting requests, even in the recycling stage. The reason I am asking is: I have a static field in my class, and I want to make that's the only static instance in the website. I've heard in some circumstances, IIS is recylcing your application, and it will start a new process, but the old process is still working, thus I will have 2 static instances in memory, which defeat the purpose of static field.
One step further, let's assume there might be 2 instances in memory, can I assume there are at most 2 instances at any single time? And can I assume once the second instance is up, the first instance will NEVER accept new requests?
Another question: Recently I have a problem with an applicationdomain concept. Looks like if an application domain causes a memory leak, unload the domain will not release the memory (Umanaged leak). So to what extent Application Domain is isolated?
I would like to know what are the best practices in using Javascript in ASP.NET in a pre-AJAX and pre-jQuery era. What I meant by pre-era is not the time before AJAX/jQuery was created, but rather the time before it is popularized and widely adopted (by a significantly large number of programmers).i.e. Is it good thing to store the script in a string variable and register it on demand (RegisterClientScriptBlock) or on startup (RegisterStartUpScript)?Although in using Javascript in ASP.NET, its usage in PHP and JSP are also welcome.
best practices to be followed in deployment of asp.net web application & WCF service in IIS 7 regarding the IIS 7 configuration settings , Security setting, application access level settings..
