Ayuda de ASP.NET MVC para acceder a las imágenes de Gravatar

Question

Si bien la API del servicio Gravatar (bueno, en realidad es solo una URL) es bastante sencilla, ¿hay un método de ayuda sencillo que refleje todas las opciones disponibles para Gravatar?

• Tamaño de imagen
• imagen predeterminada (cuando el usuario no ha especificado una)
• Valoración (G/PG/R/X)

Idealmente esto sería un método HtmlHelper extensión.

Estoy apuntando a MVC2 en .NET4, pero supongo que a otros también les interesarían las opciones de versiones anteriores.

EDIT Las implementaciones deben permitir proporcionar atributos adicionales para el elemento HTML generado también.

Answer 1

Gracias por sus respuestas. Al final, escribí mi propia solución, así que la publicaré aquí para cualquier otra persona que pueda encontrarla útil.

Proporciona todas las funciones que Gravatar admite en este momento, tal como se detalla en la pregunta.

utilizar de esta manera:

<%= Html.Gravatar(Model.User.EmailAddress) %> 

que proporcionan argumentos opcionales para cualquier, er, opciones. Estos se pueden combinar.

// Use a specific image size (the default is 80px) 
Html.Gravatar(Model.User.EmailAddress, size:64) 

// Specify what image should appear if the email address is not 
// associated with a Gravatar account 
Html.Gravatar(Model.User.EmailAddress, 
       defaultImage:GravatarDefaultImage.Identicon) 

// Specify the maximum rating allowed for images 
Html.Gravatar(Model.User.EmailAddress, rating:GravatarRating.Pg) 

// Add any additional HTML attributes for the <img /> tag 
Html.Gravatar(Model.User.EmailAddress, 
       htmlAttributes:new { @class = "gravatar" }) 

Aquí está el código:

using System; 
using System.Diagnostics; 
using System.Security.Cryptography; 
using System.Text; 
using System.Web.Mvc; 
using System.Web.Routing; 

namespace SampleNamespace 
{ 
    public static class HtmlHelperGravatar 
    { 
     /// <summary> 
     /// Creates HTML for an <c>img</c> element that presents a Gravatar icon. 
     /// </summary> 
     /// <param name="html">The <see cref="HtmlHelper"/> upon which this extension method is provided.</param> 
     /// <param name="email">The email address used to identify the icon.</param> 
     /// <param name="size">An optional parameter that specifies the size of the square image in pixels.</param> 
     /// <param name="rating">An optional parameter that specifies the safety level of allowed images.</param> 
     /// <param name="defaultImage">An optional parameter that controls what image is displayed for email addresses that don't have associated Gravatar icons.</param> 
     /// <param name="htmlAttributes">An optional parameter holding additional attributes to be included on the <c>img</c> element.</param> 
     /// <returns>An HTML string of the <c>img</c> element that presents a Gravatar icon.</returns> 
     public static string Gravatar(this HtmlHelper html, 
             string email, 
             int? size = null, 
             GravatarRating rating = GravatarRating.Default, 
             GravatarDefaultImage defaultImage = GravatarDefaultImage.MysteryMan, 
             object htmlAttributes = null) 
     { 
      var url = new StringBuilder("//www.gravatar.com/avatar/", 90); 
      url.Append(GetEmailHash(email)); 

      var isFirst = true; 
      Action<string,string> addParam = (p,v) => 
       { 
        url.Append(isFirst ? '?' : '&'); 
        isFirst = false; 
        url.Append(p); 
        url.Append('='); 
        url.Append(v); 
       }; 

      if (size != null) 
      { 
       if (size < 1 || size > 512) 
        throw new ArgumentOutOfRangeException("size", size, "Must be null or between 1 and 512, inclusive."); 
       addParam("s", size.Value.ToString()); 
      } 

      if (rating != GravatarRating.Default) 
       addParam("r", rating.ToString().ToLower()); 

      if (defaultImage != GravatarDefaultImage.Default) 
      { 
       if (defaultImage==GravatarDefaultImage.Http404) 
        addParam("d", "404"); 
       else if (defaultImage==GravatarDefaultImage.Identicon) 
        addParam("d", "identicon"); 
       if (defaultImage==GravatarDefaultImage.MonsterId) 
        addParam("d", "monsterid"); 
       if (defaultImage==GravatarDefaultImage.MysteryMan) 
        addParam("d", "mm"); 
       if (defaultImage==GravatarDefaultImage.Wavatar) 
        addParam("d", "wavatar"); 
      } 

      var tag = new TagBuilder("img"); 
      tag.MergeAttributes(new RouteValueDictionary(htmlAttributes)); 
      tag.Attributes.Add("src", url.ToString()); 

      if (size!=null) 
      { 
       tag.Attributes.Add("width", size.ToString()); 
       tag.Attributes.Add("height", size.ToString()); 
      } 

      return tag.ToString(); 
     } 

     private static string GetEmailHash(string email) 
     { 
      if (email == null) 
       return new string('0', 32); 

      email = email.Trim().ToLower(); 

      var emailBytes = Encoding.ASCII.GetBytes(email); 
      var hashBytes = new MD5CryptoServiceProvider().ComputeHash(emailBytes); 

      Debug.Assert(hashBytes.Length == 16); 

      var hash = new StringBuilder(); 
      foreach (var b in hashBytes) 
       hash.Append(b.ToString("x2")); 
      return hash.ToString(); 
     } 
    } 

    public enum GravatarRating 
    { 
     /// <summary> 
     /// The default value as specified by the Gravatar service. That is, no rating value is specified 
     /// with the request. At the time of authoring, the default level was <see cref="G"/>. 
     /// </summary> 
     Default, 

     /// <summary> 
     /// Suitable for display on all websites with any audience type. This is the default. 
     /// </summary> 
     G, 

     /// <summary> 
     /// May contain rude gestures, provocatively dressed individuals, the lesser swear words, or mild violence. 
     /// </summary> 
     Pg, 

     /// <summary> 
     /// May contain such things as harsh profanity, intense violence, nudity, or hard drug use. 
     /// </summary> 
     R, 

     /// <summary> 
     /// May contain hardcore sexual imagery or extremely disturbing violence. 
     /// </summary> 
     X 
    } 

    public enum GravatarDefaultImage 
    { 
     /// <summary> 
     /// The default value image. That is, the image returned when no specific default value is included 
     /// with the request. At the time of authoring, this image is the Gravatar icon. 
     /// </summary> 
     Default, 

     /// <summary> 
     /// Do not load any image if none is associated with the email hash, instead return an HTTP 404 (File Not Found) response. 
     /// </summary> 
     Http404, 

     /// <summary> 
     /// A simple, cartoon-style silhouetted outline of a person (does not vary by email hash). 
     /// </summary> 
     MysteryMan, 

     /// <summary> 
     /// A geometric pattern based on an email hash. 
     /// </summary> 
     Identicon, 

     /// <summary> 
     /// A generated 'monster' with different colors, faces, etc. 
     /// </summary> 
     MonsterId, 

     /// <summary> 
     /// Generated faces with differing features and backgrounds. 
     /// </summary> 
     Wavatar 
    } 
} 

Answer 2

Necesitaba esto para un proyecto así que tomé: http://www.freshclickmedia.com/blog/2008/06/aspnet-gravatar-control-update-full-source-included/

y lo convirtió en esto:

public static class GravatarHtmlHelper 
{ 
    public static Gravatar Gravatar(this HtmlHelper htmlHelper, string email) 
    { 
     return new Gravatar() {Email = email, Size = 50, MaxAllowedRating = WebControls.Gravatar.RatingType.X}; 
    } 

    public static Gravatar Gravatar(this HtmlHelper htmlHelper, string email, bool outputSiteLink) 
    { 
     return new Gravatar() { Email = email, Size = 50, MaxAllowedRating = WebControls.Gravatar.RatingType.X, OutputGravatarSiteLink = outputSiteLink }; 
    } 

    public static Gravatar Gravatar(this HtmlHelper htmlHelper, string email, short size) 
    { 
     return new Gravatar() { Email = email, Size = size, MaxAllowedRating = WebControls.Gravatar.RatingType.X }; 
    } 

    public static Gravatar Gravatar(this HtmlHelper htmlHelper, string email, short size, bool outputSiteLink) 
    { 
     return new Gravatar() { Email = email, Size = size, MaxAllowedRating = WebControls.Gravatar.RatingType.X, OutputGravatarSiteLink = outputSiteLink}; 
    } 

} 

public class Gravatar 
{ 
    public enum RatingType { G, PG, R, X } 

    private string _email; 

    // outut gravatar site link true by default: 

    // customise the link title: 

    public Gravatar() 
    { 
     OutputGravatarSiteLink = true; 
     LinkTitle = "Get your avatar"; 
    } 

    /// <summary> 
    /// The Email for the user 
    /// </summary> 

    public string Email 
    { 
     get 
     { 
      return _email; 
     } 

     set 
     { 
      _email = value.ToLower(); 
     } 
    } 

    /// <summary> 
    /// Size of Gravatar image. Must be between 1 and 512. 
    /// </summary> 
    public short Size { get; set; } 

    /// <summary> 
    /// An optional "rating" parameter may follow with a value of [ G | PG | R | X ] that determines the highest rating (inclusive) that will be returned. 
    /// </summary> 
    public RatingType MaxAllowedRating { get; set; } 

    /// <summary> 
    /// Determines whether the image is wrapped in an anchor tag linking to the Gravatar sit 
    /// </summary> 
    public bool OutputGravatarSiteLink { get; set; } 

    /// <summary> 
    /// Optional property for link title for gravatar website link 
    /// </summary> 
    public string LinkTitle { get; set; } 

    /// <summary> 
    /// An optional "default" parameter may follow that specifies the full, URL encoded URL, protocol included, of a GIF, JPEG, or PNG image that should be returned if either the requested email address has no associated gravatar, or that gravatar has a rating higher than is allowed by the "rating" parameter. 
    /// </summary> 
    public string DefaultImage { get; set; } 

    public override string ToString() 
    { 

     // if the size property has been specified, ensure it is a short, and in the range 
     // 1..512: 
     try 
     { 
      // if it's not in the allowed range, throw an exception: 
      if (Size < 1 || Size > 512) 
       throw new ArgumentOutOfRangeException(); 
     } 
     catch 
     { 
      Size = 80; 
     } 

     // default the image url: 
     string imageUrl = "http://www.gravatar.com/avatar.php?"; 

     if (!string.IsNullOrEmpty(Email)) 
     { 
      // build up image url, including MD5 hash for supplied email: 
      MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider(); 

      UTF8Encoding encoder = new UTF8Encoding(); 
      MD5CryptoServiceProvider md5Hasher = new MD5CryptoServiceProvider(); 

      byte[] hashedBytes = md5Hasher.ComputeHash(encoder.GetBytes(Email)); 

      StringBuilder sb = new StringBuilder(hashedBytes.Length * 2); 
      for (int i = 0; i < hashedBytes.Length; i++) 
      { 
       sb.Append(hashedBytes[i].ToString("X2")); 
      } 

      // output parameters: 
      imageUrl += "gravatar_id=" + sb.ToString().ToLower(); 
      imageUrl += "&rating=" + MaxAllowedRating.ToString(); 
      imageUrl += "&size=" + Size.ToString(); 
     } 

     // output default parameter if specified 
     if (!string.IsNullOrEmpty(DefaultImage)) 
     { 
      imageUrl += "&default=" + HttpUtility.UrlEncode(DefaultImage); 
     } 



     var linkBuilder = new TagBuilder("a"); 
     // if we need to output the site link: 
     if (OutputGravatarSiteLink) 
     { 
      linkBuilder.MergeAttribute("href", "http://www.gravatar.com"); 
      linkBuilder.MergeAttribute("title", LinkTitle); 
     } 

     // output required attributes/img tag: 
     var builder = new TagBuilder("img"); 
     builder.MergeAttribute("width", Size.ToString()); 
     builder.MergeAttribute("height", Size.ToString()); 
     builder.MergeAttribute("src", imageUrl); 
     builder.MergeAttribute("alt", "Gravatar"); 

     string output = builder.ToString(TagRenderMode.Normal); 
     // if we need to output the site link:) 
     if (OutputGravatarSiteLink) 
     { 
      linkBuilder.InnerHtml = builder.ToString(); 
      output = linkBuilder.ToString(TagRenderMode.Normal); 
     } 

     return output; 

    } 
} 

Uso:

<%= Html.Gravatar("john.e.farrell@gmail.com", true)%> 

que tendrá que añadir las sobrecargas al helper html cuando los necesite. No puedo hacer todo el trabajo. ;) No está mal durante 5 minutos eh?

Answer 3

La extensión del asistente de gravatar de Rob Conery vinculada a continuación sería un buen comienzo.

My Favorite Helpers For ASP.NET MVC

El código del sitio:

public static class GravatarHelper { 

    public static string Gravatar(this HtmlHelper helper, string email, int size) { 
     var result = "<img src=\"{0}\" alt=\"Gravatar\" class=\"gravatar\" />"; 
     var url = GetGravatarURL(email, size); 
     return string.Format(result, url); 
    } 

    static string GetGravatarURL(string email, int size) { 
     return (string.Format("http://www.gravatar.com/avatar/{0}?s={1}&r=PG", 
        EncryptMD5(email), size.ToString())); 
    } 

    static string GetGravatarURL(string email, int size, string defaultImagePath) { 
     return GetGravatarURL(email, size) + string.Format("&default={0}", 
        defaultImagePath); 
    } 

    static string EncryptMD5(string Value) { 
     var md5 = new MD5CryptoServiceProvider(); 
     var valueArray = System.Text.Encoding.ASCII.GetBytes(Value); 
     valueArray = md5.ComputeHash(valueArray); 
     var encrypted = ""; 
     for (var i = 0; i < valueArray.Length; i++) 
      encrypted += valueArray[i].ToString("x2").ToLower(); 
     return encrypted; 
    } 
} 

HTHS,
Charles

Answer 4

Por desgracia, no he visto tu pregunta anterior o te habría recomienda el uso de mi biblioteca Gravatar.NET he construido para proporcionar un envoltorio de .NET para el toda la API de Gravatar.

Si está interesado, echa un vistazo aquí: http://gravatarnet.codeplex.com/

Answer 5

Aquí es una etiqueta ayudante .Net Core si alguien está interesado:

uso

using System.Security.Cryptography; 
using System.Text; 
using Microsoft.AspNetCore.Razor.TagHelpers; 

namespace App.Web.TagHelpers 
{ 
    public class GravatarTagHelper : TagHelper 
    { 
     public string Id { get; set; } 

     public string Email { get; set; } 

     public int? Size { get; set; } 

     public string Class { get; set; } 

     public string Alt { get; set; } 

     public override void Process(TagHelperContext context, TagHelperOutput output) 
     { 
      output.TagName = "img"; 
      if (!string.IsNullOrWhiteSpace(Id)) 
      { 
       output.Attributes.SetAttribute("id", Id); 
      } 
      output.Attributes.SetAttribute("alt", Alt); 
      output.Attributes.SetAttribute("src", GenerateGravatarUrl(Email)); 
      if (!string.IsNullOrWhiteSpace(Class)) 
      { 
       output.Attributes.SetAttribute("class", GenerateGravatarUrl(Class)); 
      } 
      if (Size.HasValue) 
      { 
       output.Attributes.SetAttribute("width", Size.ToString()); 
       output.Attributes.SetAttribute("height", Size.ToString()); 
      } 
     } 

     private static string GenerateGravatarUrl(string email) 
     { 
      var md5 = MD5.Create(); 
      var encoder = new UTF8Encoding(); 
      var md5Hash = md5.ComputeHash(encoder.GetBytes(email.Trim().ToLower())); 
      var md5String = new StringBuilder(md5Hash.Length * 2); 
      foreach (var character in md5Hash) 
      { 
       md5String.Append(character.ToString("X2")); 
      } 
      return $"https://www.gravatar.com/avatar/{md5String.ToString().ToLower()}?d=mm"; 
     } 
    } 
} 

aquí:

https://gravatartaghelper.codeplex.com/