来自路径/路由的ASP.NET Core API搜索参数

我正在移植一个使用$params = $this->uri->uri_to_assoc()的PHP/CI API，以便它可以接受具有许多组合的GET请求，例如:

https://server/properties/search/beds/3/page/1/sort/price_desc

https://server/properties/search/page/2/lat/34.1/lon/-119.1

https://server/properties/search

等

有很多类似的代码:

$page = 1;
if (!empty($params['page'])) {
    $page = (int)$params['page'];
}

我尝试过的两种ASP.NET Core 2.1技术似乎都太过复杂了，因此，我希望对更好的解决方案提供任何指导:

1)具有包罗万象的常规路由:

app.UseMvc(routes => {
                routes.MapRoute(
                    name: "default",
                    template: "{controller=Properties}/{action=Search}/{*params}"
                );
            });

2)属性路由:

    [HttpGet("properties/search")]
    [HttpGet("properties/search/beds/{beds}")]
    [HttpGet("properties/search/beds/{beds}/page/{page}")]
    [HttpGet("properties/search/page/{page}/beds/{beds}")]
    public IActionResult Search(int beds, double lat, double lon, int page = 1, int limit = 10) {
}

不能更改这些端点的签名。

最佳答案

FromPath值提供者

您想要的是将一个复杂的模型绑定(bind)到URL路径的一部分。不幸的是，ASP.NET Core没有内置的FromPath绑定(bind)器。不过，幸运的是，我们可以构建自己的。

这是一个example FromPathValueProvider in GitHub，其结果如下:



基本上，它绑定(bind)domain.com/controller/action/key/value/key/value/key/value。这与FromRoute或FromQuery值提供程序所做的不同。

使用FromPath值提供程序

创建这样的路线:

routes.MapRoute(
    name: "properties-search",
    template: "{controller=Properties}/{action=Search}/{*path}"
);

将[FromPath]属性添加到您的操作中:

public IActionResult Search([FromPath]BedsEtCetera model)
{
    return Json(model);
}

神奇的是它将*path绑定(bind)到一个复杂的模型:

public class BedsEtCetera
{
    public int Beds { get; set; }
    public int Page { get; set; }
    public string Sort { get; set; }
}

创建FromPath值提供程序

基于 FromRoute 创建一个新属性。

[AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Property,
    AllowMultiple = false, Inherited = true)]
public class FromPath : Attribute, IBindingSourceMetadata, IModelNameProvider
{
    /// <inheritdoc />
    public BindingSource BindingSource => BindingSource.Custom;

    /// <inheritdoc />
    public string Name { get; set; }
}

在 RouteValueProviderFactory .上创建一个新的IValueProviderFactory

public class PathValueProviderFactory : IValueProviderFactory
{
    public Task CreateValueProviderAsync(ValueProviderFactoryContext context)
    {
        var provider = new PathValueProvider(
            BindingSource.Custom,
            context.ActionContext.RouteData.Values);

        context.ValueProviders.Add(provider);

        return Task.CompletedTask;
    }
}

在 RouteValueProvider 上创建一个新的IValueProvider。

public class PathValueProvider : IValueProvider
{
    public Dictionary<string, string> _values { get; }

    public PathValueProvider(BindingSource bindingSource, RouteValueDictionary values)
    {
        if(!values.TryGetValue("path", out var path))
        {
            var msg = "Route value 'path' was not present in the route.";
            throw new InvalidOperationException(msg);
        }

        _values = (path as string).ToDictionaryFromUriPath();
    }

    public bool ContainsPrefix(string prefix) => _values.ContainsKey(prefix);

    public ValueProviderResult GetValue(string key)
    {
        key = key.ToLower(); // case insensitive model binding
        if(!_values.TryGetValue(key, out var value)) {
            return ValueProviderResult.None;
        }

        return new ValueProviderResult(value);
    }
}

PathValueProvider使用ToDictionaryFromUriPath扩展方法。

public static class StringExtensions {
    public static Dictionary<string, string> ToDictionaryFromUriPath(this string path) {
        var parts = path.Split('/');
        var dictionary = new Dictionary<string, string>();
        for(var i = 0; i < parts.Length; i++)
        {
            if(i % 2 != 0) continue;
            var key = parts[i].ToLower(); // case insensitive model binding
            var value = parts[i + 1];
            dictionary.Add(key, value);
        }

        return dictionary;
    }
}

在Startup类中将所有内容连接在一起。

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc()
            .AddMvcOptions(options =>
                options.ValueProviderFactories.Add(new PathValueProviderFactory()));
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        app.UseMvc(routes => {
            routes.MapRoute(
                name: "properties-search",
                template: "{controller=Properties}/{action=Search}/{*path}"
            );
        });
    }
}

这是a working sample on GitHub。

关于来自路径/路由的ASP.NET Core API搜索参数，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/51092342/