Use JavaScript Variable in Asp.net MVC Razor syntax

Question

How to use JavaScript variables inside ASP.NET MVC Razor instructions?

Example:

function updChart(_IndId) {

    @foreach (var d in Model.Where(p => p.IndId.Equals(_IndId)))

...
}

I can't use _IndId variable. Any idea how to use it?

Doesn't work Div. Where should I declare that function? Inside my updChart function or outside? — Richasantos, Oct 06 '16 at 16:06
Possible duplicate of [How to pass a value to razor variable from javascript variable?](http://stackoverflow.com/questions/28317182/how-to-pass-a-value-to-razor-variable-from-javascript-variable) — Heretic Monkey, Oct 06 '16 at 16:31

score 5 · Answer 1 · answered Oct 06 '16 at 16:06

You can not use Javascript variables in C#, because javascript code is available only after C# / Razor is rendered.

What you can do, is to save the Model in a Javascript array, and then do the foreach loop in Javascript:

var model = [];
@foreach (var item in Model)
{
    @:model.push({
        @:ID: '@item.ID',
        @:Property1: '@item.Property1',
        @:Property2: '@item.Property2',
        @:Property3: '@item.Property3',
    @:});
}

console.log(model);
// here you can filter and do the foreach in Javascript, because your model is available as a Javascript array

Alexey Andrushkevich · Accepted Answer · 2016-10-06T16:03:57.040

2

You cannot do this. The Razor view is compiled and executed on server and its result is HTML page which is then returned to a client(browser). JavaScript runs in browser and allows you to work with the DOM of HTML page which is already returned from the server.

edited Oct 06 '16 at 16:03

answered Oct 06 '16 at 16:02

Alexey Andrushkevich

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So whats my alternative here? – Richasantos Oct 06 '16 at 16:03
If you need to partially update something on your page you have to make AJAX request to the server, get data and apply it to a specific part of your page. – Alexey Andrushkevich Oct 06 '16 at 16:08
Razor is a generic templating engine and *could* be adapted to return JavaScript. I see this as an area that will probably be addressed in the future. I suppose there's nothing stopping you from creating an MVC endpoint that pre-processes the JavaScript files. – mark gamache Feb 20 '17 at 16:04

Use JavaScript Variable in Asp.net MVC Razor syntax

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