Set up C# project

Let's start with a fresh ASP.NET project by executing dotnet new webapidotnet new webapi in a new directory. The starter project has a single endpoint defined in Program.csProgram.cs. We can try that endpoint out in the swagger UI. Start up the service (dotnet rundotnet run) and follow the link printed in the terminal. If the page is empty, navigate to /swagger/swagger. In the swagger UI, expand the /weatherforecast/weatherforecast endpoint, press "Try it out", then "Execute". This will send an HTTP request to the running ASP.NET service and return made up weather data.

We will define a new endpoint to compile our Oicana template to a PDF and return the PDF file to the user.

1. Create a new directory in the .NET project called templatestemplates and copy example-0.1.0.zipexample-0.1.0.zip into that directory.
2. Add the OicanaOicana NuGet package as a dependency with dotnet add package Oicana --prereleasedotnet add package Oicana --prerelease.

3. Read the template file and prepare it for compilation at the beginning of Program.csProgram.cs:

   
   

   using Oicana.Config;

   using Oicana.Template;

   var templateFile =

       await File.ReadAllBytesAsync("templates/example-0.1.0.zip");

   var template = new Template(templateFile);

   using Oicana.Config;

   using Oicana.Template;

   var templateFile =

       await File.ReadAllBytesAsync("templates/example-0.1.0.zip");

   var template = new Template(templateFile);

   using Oicana.Config;

   using Oicana.Template;

   var templateFile =

       await File.ReadAllBytesAsync("templates/example-0.1.0.zip");

   var template = new Template(templateFile);

   using Oicana.Config;

   using Oicana.Template;

   var templateFile =

       await File.ReadAllBytesAsync("templates/example-0.1.0.zip");

   var template = new Template(templateFile);

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4. Replace the generated /weatherforecast/weatherforecast endpoint with the following:

   app.MapPost("compile", () =>

   {

       var stream = template.Compile([], [], CompilationOptions.Pdf());

       var now = DateTimeOffset.Now;

       return Results.File(

           fileStream: stream,

           contentType: "application/pdf",

           fileDownloadName: $"example_{now:yyyy_MM_dd_HH_mm_ss_ffff}.pdf"

       );

   })

   .WithOpenApi();

   app.MapPost("compile", () =>

   {

       var stream = template.Compile([], [], CompilationOptions.Pdf());

       var now = DateTimeOffset.Now;

       return Results.File(

           fileStream: stream,

           contentType: "application/pdf",

           fileDownloadName: $"example_{now:yyyy_MM_dd_HH_mm_ss_ffff}.pdf"

       );

   })

   .WithOpenApi();

   app.MapPost("compile", () =>

   {

       var stream = template.Compile([], [], CompilationOptions.Pdf());

       var now = DateTimeOffset.Now;

       return Results.File(

           fileStream: stream,

           contentType: "application/pdf",

           fileDownloadName: $"example_{now:yyyy_MM_dd_HH_mm_ss_ffff}.pdf"

       );

   })

   .WithOpenApi();

   app.MapPost("compile", () =>

   {

       var stream = template.Compile([], [], CompilationOptions.Pdf());

       var now = DateTimeOffset.Now;

       return Results.File(

           fileStream: stream,

           contentType: "application/pdf",

           fileDownloadName: $"example_{now:yyyy_MM_dd_HH_mm_ss_ffff}.pdf"

       );

   })

   .WithOpenApi();

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   This code defines a new POST endpoint at /compile/compile. For every request, it compiles the template to PDF with two empty input lists and returns the file.

After restarting the service and refreshing the swagger UI, you should see the new endpoint. Open up the endpoint description and click "Try it out" and "Execute" to send a request to the server. You should see a successful response with a download button for the PDF file.

The PDF generation should not take longer than a couple of milliseconds. You can look at the request duration in the network tab of your browser's debugging tools for an estimation. The first request to an APS.NET service can be significantly slower than later ones, because ASP.NET does some preparation during the first request.

For a better measurement of the compilation speed on your machine, you can use a StopwatchStopwatch in the endpoint code.

Next up: add dynamic inputs to the Oicana template.