Best way to run a string as c# code

Question

Let's say I have:

@{
var str= "DateTime.Now";
}

I want to process this string as a c# code

@Html.Raw(App.ProcessAsCode(str));

The output should be the current date time.

"Best" would likely be to "don't do that" - this is asking how to "`eval`". Basically, unless you *need* to accept arbitrary code as text (which is potentially dangerous and generally only useful for things like online "fiddles"), *don't*. So .. what's the *real* problem being solved? xD — user2864740, Feb 06 '14 at 23:42
`run a string as c# code` Do you mean what the compiler does ? You **shouldn't** do something like this and I don't see any reason to do that. — Selman Genç, Feb 06 '14 at 23:43
@Selman22 Arbitrary code *can* be run, given the appropriate environment and context. Consider how a tool like LINQPad, or the Immediate Window in the debugger. — user2864740, Feb 06 '14 at 23:43
@user2864740 ofcourse it is possible if you think like that,what I mean by you can't is it's highly unnecessary in this case. — Selman Genç, Feb 06 '14 at 23:45
@Selman22: You're confusing the words "can't" and "probably shouldn't". — David, Feb 06 '14 at 23:46
Often when I use a CMS text editor to write html, I think of writing simple code like #DateTime.Now# in the html editor and the page will process it as c# code NOT html. This is just a question that keep coming into my mind sometimes. — eadam, Feb 06 '14 at 23:52
@Ibn-e-Adam If you are using this for a CMS based in .NET I would recommend looking into the .Liquid engine. See: https://github.com/formosatek/dotliquid/ — drew_w, Feb 06 '14 at 23:56

score 5 · Accepted Answer · edited May 23 '17 at 11:56

Final Edit:

Based on further information - if the goal here is to simply have a formatting engine there are lots of options out there. One such option is based around the .liquid syntax from shopify (see here). You can find a .NET port of this on gitHub here: https://github.com/formosatek/dotliquid/. The main purpose of this is to turn something like:

 <h2>{{product.name}}</h2>

Into something like:

 <h2>Beef Jerky</h2>

I would strongly recommend reading more about the liquid engine and syntax and I believe this will lead you in the right direction. Best of luck!

Initial Answer

This is definitely possible - although as others have said you will want to be careful in what you do. Using C# the key to compiling and running code generically is the "CSharpCodeProvider" class. Here is a brief example of how that looks:

        string[] references = { "System.dll" };
        CompilerParams.ReferencedAssemblies.AddRange(references);

        var provider = new CSharpCodeProvider();
        CompilerResults compile = provider.CompileAssemblyFromSource(CompilerParams, formattedCode);

In this example, "formattedCode" is a string with the C# code. Any references must be manually added. For the full example see this stack question (How to get a Type from a C# type name string?).

NOTE -- If all you are looking to do here is a format string or something simple like that you might have the user pass in a .NET format string (eg "MM/dd/yyyy"), then use that in a call to the "ToString" method. That would provide the user some configurability, while still making sure your system stays secure. In general running code on a server that hasn't been properly checked/escaped is really dangerous!

Reference - For your reference, the current msdn page for CSharpCodeProvider also has some examples.

Thanks for your answer, please see my comment above. Just looking for the fastest way to write html PLUS simple c# snippets in a text editor. — eadam, Feb 06 '14 at 23:55
@Ibn-e-Adam I believe my update (posted to the beginning of the question) is a good place to start. You are basically looking for a templating engine like .liquid. Best of luck! — drew_w, Feb 07 '14 at 00:01

score 0 · Answer 2 · answered Feb 06 '14 at 23:55

0

Another option would be using a dynamic language such as IronRuby or IronPython.

answered Feb 06 '14 at 23:55

mason

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Best way to run a string as c# code

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