So the ASP.NET MVC 3 RTM is out and the real icon of this release is the Razor View Engine. The best thing of Razor is that unlike its predecessor(webforms) it is not tied with the web environment, we can easily host it outside the web and use it as template engine for various purpose. The project that I am currently working on needs to send bulk emails at various point of the application, since the numbers can be hundreds or literary thousands I want to host it outside the web application so that it does add unnecessary overheads to the web application. In this post, I will show you you the code that I am using to generate these mails, you can download the complete code with MSpec specs from the bottom of the post.
Lets say, in your application you want to send a welcome mail to user, whenever s/he registers. To send the mail you can use the following code:
And here is the template that it will use to generate the actual mail content:
The code is very simple, first we are creating an anonymous object as model, you can also use strongly typed as well as the new dynamic object, next we are using the template engine to generate the output and at last the mail object is passed to the mail sender for dispatching it. In the template the model is that we passed from the method is exposed as the dynamic object. Behind the scene the template uses a base class which has some of the common properties that we often use for setting the mail:
It is also possible to compose a mail which contains both text and html format, so that the mail client which supports html should use the html version and the unsupported client could use the plain version. To compose a multi formatted mail you will have to use three templates the shared template will contain the common properties like From/To/Subject etc. and the other two will contain the actually body. For example, to use the above mail in multi format we will create the following templates:
Now, when the mail is sent it should look like the following:
Currently it uses templates which are stored in the file system, but it is extensible enough to store the templates in other mediums like database. Like ASP.NET it compiles the templates to .NET types when first time it is requested, but it does not have the cache invalidation support like asp.net, may be I will add it in future.