Add property and value to C# List

Question

The goal

Add property and value to List. I'm using C#/MVC 4/Razor.

The problem

I have the following:

return PartialView("_CategoriesList", db.bm_product_categories.ToList());

Ok, all good here. My list returns me multiple columns from database and one of them is Category_Name. I want to "slugify" each category name with C# and then pass to view. I was thinking in something like this:

foreach (var categorySlug in db.bm_product_categories)
{
    db.bm_product_categories
       .Add({
              "Category_Name_Slugged":
              Helpers.Slugify(db.bm_product_categories.Category_Name)
           });
}

But, obviously, this syntax is wrong — I do not know what to do.

Ideas?

score 2 · Answer 1 · edited Jun 14 '13 at 14:37

2

You can use something like this , if you can make a copy of the data and work

var sluggifiedList = (from category in db.bm_product_categories  
select category.CategoryName.Slugify()).ToList();

else

(from categoryName in db.bm_product_categories.CategoryName      
select categoryName).ToList().ForEach  
(category_Name => category_Name = category_Name.Slugigy());

edited Jun 14 '13 at 14:37

nawfal

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answered Jun 14 '13 at 14:34

srsyogesh

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Whoever downvoted this is pretty smart to decipher this in seconds. – nawfal Jun 14 '13 at 14:36
Hello. In my view my model was `@model IEnumerable` — And now, as it will be? – Guilherme Oderdenge Jun 14 '13 at 14:56
i think you dont have to too worry about where to place this internal class , u can create a new cs file and place this code or add this new class in any of the existing file , of course in the same project – srsyogesh Jun 14 '13 at 15:29
@srsyogesh My question is: what I have to put on the first line of my View? – Guilherme Oderdenge Jun 14 '13 at 16:57
I havent learned asp.net yet :( so i am not sure what to specify in the View. – srsyogesh Jun 17 '13 at 06:51

score 1 · Answer 2 · edited May 23 '17 at 11:50

1

You can project the altered model using LINQ, such as:

var sluggifiedProjection = 
  db.bm_product_categories
    .ToList() // Need to materialize here. Ensure any filters applied before this.
    .Select(cat => new 
      {
        CategoryNameSlugged = Helpers.Slugify(cat.Category_Name) 
        // .. + other fields of bm_product_categories needed by your view
      });

 return PartialView("_CategoriesList", sluggifiedProjection);

The creates a list of an anonymous class - you could obviously also create a new typed ViewModel class as well for CategoryNameSlugged and share this class with your View. See also Can I pass an anonymous type to my ASP.NET MVC view?

Update

As per the linked post, you can either leave the projection as anonymous, and then in the Razor View, use a dynamic or reflection to access the CategoryNameSlugged property from the list, or alternatively (and preferably), you can use a strongly typed ViewModel class:

internal class SluggedCategoriesViewModel
{
    public string CategoryNameSlugged {get; set; }
    // Add any other properties from bm_product_categories that your view needs, e.g.
    public int CategoryId {get; set; }
}

And the projection now uses the strongly typed ViewModel class:

  .Select(cat => new SluggedCategoriesViewModel
    {
      CategoryNameSlugged = Helpers.Slugify(cat.Category_Name),
      CategoryId = cat.Category_Id // etc
    });

edited May 23 '17 at 11:50

Community

1
1

answered Jun 14 '13 at 14:25

StuartLC

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`.Category_Name` from `db.bm_product_categories` was not found — what do I have to do? – Guilherme Oderdenge Jun 14 '13 at 14:29
Oh, Stuart, thanks! But my `Slugify()` method has a problem: `LINQ to Entities does not recognize the method 'System.String Slugify(System.String)' method, and this method cannot be translated into a store expression.`. What do you think about this? – Guilherme Oderdenge Jun 14 '13 at 14:34
My bad again ... you will need to materialize your db.bm_product_categories before projecting it. Updated. – StuartLC Jun 14 '13 at 14:35
No problem, Stuart. But, in my view, how will be the Model? – Guilherme Oderdenge Jun 14 '13 at 14:46
Oh, thanks! Thank you so much, really really! Just one last question: this internal classe — what is the best place to put it? – Guilherme Oderdenge Jun 14 '13 at 15:01
I would suggest you create a new folder in your MVC project called 'ViewModels' and put classes like this there (the namespace might change). – StuartLC Jun 14 '13 at 15:18
Okay! Oh, an unforeseen happened... I do not know how @model, at View, have to be — can you clarify this for me? Anyway, thank you very much again! – Guilherme Oderdenge Jun 14 '13 at 15:20

Sam Leach · Answer 3 · 2013-06-14T14:24:53.317

0

List<bm_product_categories> list = new List<bm_product_categories>();

foreach(string name in list.Select(x => x.Category_Name))
{ 
    slugifiedList.Add(name.Slugify()); // make extension method
}

or copy the List<bm_product_categories> and change the Category_Name property

edited Jun 14 '13 at 14:24

answered Jun 14 '13 at 14:19

Sam Leach

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Add property and value to C# List

The goal

The problem

3 Answers3