[feature] stdlib/apis: Adding API to Gravatar (http://gravatar.com)

stdlib/apis/gravatar/gravatar.opa

@@ -0,0 +1,110 @@
+/*
+    Copyright © 2012 MLstate
+
+    This file is part of OPA.
+
+    OPA is free software: you can redistribute it and/or modify it under the
+    terms of the GNU Affero General Public License, version 3, as published by
+    the Free Software Foundation.
+
+    OPA is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for
+    more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with OPA.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+import stdlib.{crypto, web.mail}
+
+/**
+ * Type of a default image to be served by the Gravatar service.
+ * Below descriptions taken from: http://en.gravatar.com/site/implement/images/
+ */
+type Gravatar.default_image =
+  { ret_404 } /       /** do not load any image if none is associated with the email
+                          hash, instead return an HTTP 404 (File Not Found) response */
+  { mystery_man } /   /** a simple, cartoon-style silhouetted outline of a person
+                          (does not vary by email hash) */
+  { identicon } /     /** a geometric pattern based on an email hash */
+  { monsterid } /     /** a generated 'monster' with different colors, faces, etc */
+  { wavatar } /       /** generated faces with differing features and backgrounds */
+  { retro } /         /** awesome generated, 8-bit arcade-style pixelated faces */
+  { custom: Uri.uri } /** Custom, user-supplied default */
+
+/**
+ * Filtering profile images by self-imposed ratings.
+ * Below descriptions taken from: http://en.gravatar.com/site/implement/images/
+ */
+type Gravatar.rating =
+  { G } /   /** suitable for display on all websites with any audience type. */
+  { PG } /  /** may contain rude gestures, provocatively dressed individuals,
+                the lesser swear words, or mild violence. */
+  { R } /   /** may contain such things as harsh profanity, intense violence,
+                nudity, or hard drug use. */
+  { X }     /** may contain hardcore sexual imagery or extremely disturbing violence. */
+
+/**
+ * Various options for an image request to the Gravatar service
+ */
+type Gravatar.option =
+  { size : int } /                            /** Image size (image is square) */
+  { default_img : Gravatar.default_image } /  /** Default image type */
+  { forceDefault } /                          /** Force default image */
+  { rating : Gravatar.rating } /              /** Filtering by image ratings */
+  { secure }                                  /** Forces serving via SSL */
+
+/**
+ * This module provides API for the Gravatar service, providing profile
+ * images that are easy to use across many different sites.
+ */
+Gravatar = {{
+
+  @stringifier(Gravatar.default_image) default_to_string(default) =
+    match default with
+    | {ret_404} -> "404"
+    | {mystery_man} -> "mm"
+    | {identicon} -> "identicon"
+    | {monsterid} -> "monsterid"
+    | {wavatar} -> "wavatar"
+    | {retro} -> "retro"
+    | {custom=uri} -> Uri.to_string(uri) |> Uri.encode_string
+
+  @stringifier(Gravatar.rating) rating_to_string(rating) =
+    match rating with
+    | {G} -> "g"
+    | {PG} -> "pg"
+    | {R} -> "r"
+    | {X} -> "x"
+
+  @private mk_option =
+  | ~{size} -> ("s", String.of_int(size))
+  | ~{default_img} -> ("d", "{default_img}")
+  | {forceDefault} -> ("f", "y")
+  | ~{rating} -> ("r", "{rating}")
+  | {secure} -> error("Should not happen; cannot make option of \{secure}")
+
+   /**
+    * Returns an URL to a Gravatar image.
+    *
+    * @param email User's email address
+    * @param options List of options for the generated image
+    * @return An URL to the profile image associated with [email] and with
+    *         the requested [options].
+    */
+  mk_url(email : Email.email, options : list(Gravatar.option)) : Uri.uri =
+    secure = List.mem({secure}, options)
+    email_hash =
+      Email.to_string_only_address(email)
+      |> String.trim |> String.to_lower |> Crypto.Hash.md5
+    uri =
+      { Uri.default_absolute with
+        schema = some(if secure then "https" else "http")
+        domain = if secure then "secure.gravatar.com" else "www.gravatar.com"
+        path = ["avatar", email_hash]
+        query = List.map(mk_option, List.remove({secure}, options))
+      }
+    Uri.of_absolute(uri)
+
+}}