How to define view-level variables in ASP.NET MVC?

Question

I have a cshtml partial view (Razor engine) that is used to render something recursively. I have two declarative HTML helper functions defined in this view and I need to share a variable between them. In other words, I want a view-level variable (not function-level variable).

@using Backend.Models;
@* These variables should be shared among functions below *@    
@{
    List<Category> categories = new ThoughtResultsEntities().Categories.ToList();
    int level = 1;
}

@RenderCategoriesDropDown()

@* This is the first declarative HTML helper *@
@helper RenderCategoriesDropDown()
{
    List<Category> rootCategories = categories.Where(c => c.ParentId == null).ToList();
    <select id='parentCategoryId' name='parentCategoryId'>
    @foreach (Category rootCategory in rootCategories)
    {
        <option value='@rootCategory.Id' class='level-@level'>@rootCategory.Title</option>
        @RenderChildCategories(rootCategory.Id);
    }
</select>
}

@* This is the second declarative HTML helper *@
@helper RenderChildCategories(int parentCategoryId)
{
    List<Category> childCategories = categories.Where(c => c.ParentId == parentCategoryId).ToList();
    @foreach (Category childCategory in childCategories)
    {
        <option value='@childCategory.Id' class='level-@level'>@childCategory.Title</option>
        @RenderChildCategories(childCategory.Id);
    }
}

Darin Dimitrov · Accepted Answer · 2011-06-30 11:45:45Z

6

You can't do this. You will need to pass them as arguments to your helper functions:

@using Backend.Models;
@{
    List<Category> categories = new ThoughtResultsEntities().Categories.ToList();
    int level = 1;
}

@RenderCategoriesDropDown(categories, level)

@helper RenderCategoriesDropDown(List<Category> categories, int level)
{
    List<Category> rootCategories = categories.Where(c => c.ParentId == null).ToList();
    <select id='parentCategoryId' name='parentCategoryId'>
    @foreach (Category rootCategory in rootCategories)
    {
        <option value='@rootCategory.Id' class='level-@level'>@rootCategory.Title</option>
        @RenderChildCategories(categories, level, rootCategory.Id);
    }
    </select>
}

@helper RenderChildCategories(List<Category> categories, int level, int parentCategoryId)
{
    List<Category> childCategories = categories.Where(c => c.ParentId == parentCategoryId).ToList();
    @foreach (Category childCategory in childCategories)
    {
        <option value='@childCategory.Id' class='level-@level'>@childCategory.Title</option>
        @RenderChildCategories(categories, level, childCategory.Id);
    }
}

edited Jun 30, 2011 at 11:45

answered Jun 30, 2011 at 11:33

Darin Dimitrov

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1 Comment

Saeed Neamati Over a year ago

Are you sure? I mean, it's really ridiculous if we can't share variables. I think of Razor views as a scope and I think that variables could be defined in this scope. Though this answer helped me to do what I wanted to do, but I'm not sure about it. Thank you anyway for helping. :)

lorond · Accepted Answer · 2017-01-12 12:31:23Z

1

You can do this. View is just a class. You can easily declare a new field onto this class and use it anywhere in the code of your view:

@functions
{
    private int level = 0;
}

edited Jan 12, 2017 at 12:31

answered Jan 12, 2017 at 12:09

lorond

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1 Comment

Suraj Jain Over a year ago

Done. Deleted Comment.

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