G4mvc 5.0.4-preview.104

G4mvc

G4mvc is a source generator for ASP.NET Core MVC apps that creates strongly typed helpers that eliminate the use of literal strings for routing.

It is an improved re-implementation of R4MVC using a C# Source Generator because R4MVC lacks support for many newer language - and MVC features.

Installation

Install the G4mvc and G4mvc.Generator NuGet packages.

To enable the use of the tag helpers for anchor and form tags, add the @addTagHelper *, G4mvc directive either in the view, or in the _ViewImports.cshtml to enable them globally.

If you want to use the IUrlHelper and IHtmlHelper Extension methods, add a using directive for G4mvc.Extensions either in the view, or in the _ViewImports.cshtml to enable them globally.

It might be necessary to restart Visual Studio for these changes to take affect.

Use

Source Generation

Controllers

In order for the code generation to work, the controller class has to derive from the Microsoft.AspNetCore.Mvc.Controller class. Abstract classes will also be ignored. All Methods for which a routing helper should be generated, have to return Microsoft.AspNetCore.Mvc.IActionResult, Microsoft.AspNetCore.Mvc.Infrastructure.IConvertToActionResult or an implementation of either of these interfaces. For asyncronous controller actions, the task has to return one of these.

Examples:

public IActionResult Edit(EditViewModel viewModel)
public JsonResult Edit(EditViewModel viewModel)
public Task<IActionResult> Edit(EditViewModel viewModel)
public Task<JsonResult> Edit(EditViewModel viewModel)
public IConvertToActionResult Edit(EditViewModel viewModel)
public ActionResult<IEnumerable<string>> Edit(EditViewModel viewModel)

Something like public IEnumerable<string> Edit(EditViewModel viewModel) would be ignored.

Links

To trigger the generation of the links class, it is necessary to manually build or rebuild the ASP.net core project or make change in the config file.
If you are using a StaticFilesPath different from the default wwwroot or add AdditionalStaticFilesPaths, you also have to add that path to the project file as AdditionalFiles.

<ItemGroup>
  <AdditionalFiles Include="mystaticfiles\**" />
</ItemGroup>

In case of ExcludedStaticFileExtensions or ExcludedStaticFileDirectories it's recommended to adjust the AdditionalFiles entry accordingly.

Extensions

The G4mvc package provides a number of extension methods that can make using the generated route helpers a bit easier. You do however not have to rely on these because the G4mvcRouteValues class derives from the standard Microsoft.AspNetCore.Routing.RouteValueDictionary, so you can use any of the methods provided by ASP.NET Core, that have an object routeValues parameter. An example would be the HtmlHelper.RouteLink Method. The provided extension methods are just wrappers for these methods.
For the generated G4mvcContentLink fields, you can use the IUrlHelper.Content extension method to get the virtual path.

Tag Helpers

g4-action

This tag helper can be used on anchor as well as form tags. It creates the href attribute for anchor tags or the action attribute for form tags.
<a g4-action="MVC.Home.Index()">Home</a>

g4-content

For static files, which are part of the generated Links, the g4-content tag helper can be applied to all html tags, that expect a file. It creates the attribute with the virtual path to the file.
<img g4-content="Links.images.sample_svg" />

Supported html tags:

• embed
• iframe
• img
• object
• script
• source
• link
• track
• video

Configuration

You can provide a JSON config file called g4mvc.json to change some of the defaults G4mvc uses.
The json schema is available under https://schemastore.af-styx.com/Schema/G4mvc.json (alternative: https://raw.githubusercontent.com/andref15/G4mvc/main/Json/schema.json)

{
  "$schema": "https://schemastore.af-styx.com/Schema/G4mvc.json",
  "HelperClassName": "MVC",
  "LinksClassName":  "Links",
  "StaticFilesPath": "wwwroot",
  "UseVirtualPathProcessor": false,
  "UseProcessedPathForContentLink": false,
  "MakeGeneratedClassesInternal": false,
  "GeneratedClassNamespace": "global",
  "EnableSubfoldersInViews": false,
  "ExcludedStaticFileExtensions": [],
  "ExcludedStaticFileDirectories": [],
  "AdditionalStaticFilesPaths": {},
  "CustomStaticFileDirectoryAlias": {}
}

HelperClassName

Allows you to change the MVC prefix (e.g. MVC.Home.Index()). Default is MVC.

LinksClassName

Allows you to chnage the name of the class in which the links for static files are generated in. Default is Links.

StaticFilesPath

The root path (relative to project dir) for which links will be generated. Default is wwwroot.

UseVirtualPathProcessor

Defines if you want to define a custom VirtualPathProcessor funcion. By default this is false. When this is set to true, a partial class VirtualPathProcessor with a partial method Process will be generated and you have to write the implementation of this partial method. An example of this can be seen here:

internal static partial class VirtualPathProcessor
{
    public static partial string Process(string path)
    {
        return path.ToUpper();
    }
}

UseProcessedPathForContentLink

Defines if the processed path from the VirtualPathProcessor should be used for UrlHelper.Content methods and the g4-content tag helper.
If this value is undefined and UseVirtualPathProcessor is set to true, this defaults to true.

MakeGeneratedClassesInternal

Defines if the generated route classes and the MVC and Links class will be public or internal. Default is false.

GeneratedClassNamespace

Defines in which namespace the generated MVC and Links class will exist. If this value is undefined, this defaults to global

• global defines that the files will exist in the global namespace (aka no namespace)'
• project defines that the files will exist in the root namespace of the web project
• any other value will be set as the namespace (eg. G4mvc.SampleMVC)
  • If the value starts with a . the namespace will be relative to the project root namespace (e.g. .Generated)

EnableSubfoldersInViews

Defines if subfolders in the controller's Views folder should be supported. Default is false.

ExcludedStaticFileExtensions

A list of file extensions that will be excluded from the Links generation.

ExcludedStaticFileDirectories

A list of directories (relative to project dir) that will be excluded from the Links generation. This can be useful if you, for example, want to exclude a directory of a library, because you never reference these files directly.

AdditionalStaticFilesPaths

A dictionary of additional static file paths for which links will be generated. This is useful when you use the UseStaticFiles method to serve files that are outside of the wwwroot folder. The key of this dictionary is the physical path relative to the project root and the value is the request path.

For the example provided in the Microsoft Documentation the AdditionalStaticFilesPaths configuration would look like this:

"AdditionalStaticFilesPaths": {
    "MyStaticFiles": "StaticFiles"
}

CustomStaticFileDirectoryAlias

A dictionary of aliases for certain directories (relative to project dir). This can be useful if the sanitized names of two or more subdirectories in a directory are the same and renaming them is not an option. E.g. if you had a directory called some-directory and another one called some.directory in the wwwroot directory, the sanitized name of both of these would be some_directory, therefore the same class name would be generated twice. To fix the situation described, a possible configuration would be the following:

"CustomStaticFileDirectoryAlias": {
    "wwwroot/some.directory": "SomeDotDirectory"
}