Better json management

source/ap/activity_stream.d

@@ -9,10 +9,13 @@ import util;
  * https://www.w3.org/TR/activitypub/#obj
  +/
 class ASObject {
+  // Required fields (for root objects)
   string context; /// Must be activitystream context
   string id; /// AP requirement for unique identifier
   string type; /// AP requirement for type of object
 
+  // Optional fields
+
   JSONValue raw;
 
   /++ 
@@ -25,24 +28,23 @@ class ASObject {
     with (this) {
       const(JSONValue)* ascontext = "@context" in json;
 
-      if (ascontext == null)
-        throw new Exception("No context in ActivityStream Object");
+      if (ascontext) {
+        switch ((*ascontext).type) {
+        case JSONType.ARRAY:
+          context = (*ascontext)[0].str;
+          break;
 
-      switch ((*ascontext).type) {
-      case JSONType.ARRAY:
-        context = (*ascontext)[0].str;
-        break;
+        case JSONType.STRING:
+          context = (*ascontext).str;
+          break;
 
-      case JSONType.STRING:
-        context = (*ascontext).str;
-        break;
-
-      default:
-        throw new Exception("Invalid @context type for ActivityStream Object");
+        default:
+          throw new Exception("Invalid @context type for ActivityStream Object");
+        }
       }
 
-      id = json.requiredKey!"id".str;
-      type = json.requiredKey!"type".str;
+      optional(json, "id", id);
+      optional(json, "type", type);
 
       raw = json;
     }

source/ap/actor.d

@@ -33,19 +33,16 @@ class Actor : ASObject {
     super(json);
 
     with (this) {
-      inbox = json.requiredKey!"inbox".str;
-      outbox = json.requiredKey!"outbox".str;
-      following = json.requiredKey!"following".str;
-      followers = json.requiredKey!"followers".str;
+      required(json, "inbox", inbox);
+      required(json, "outbox", outbox);
+      required(json, "following", following);
+      required(json, "followers", followers);
 
-      liked = json.checkKey!string("liked");
-      streams = json.checkKey!string("streams");
-      preferredUsername = json.checkKey!string("preferredUsername");
+      optional(json, "liked", liked);
+      optional(json, "streams", streams);
+      optional(json, "preferredUsername", preferredUsername);
 
-      if (JSONValue* j = "endpoints" in json)
-        endpoints = ActorEndpoints.fromJson(*j);
-      else
-        endpoints = ActorEndpoints();
+      endpoints = ActorEndpoints.fromJson(json.optional!JSONValue("endpoints"));
 
       raw = json;
     }
@@ -64,12 +61,12 @@ struct ActorEndpoints {
     ActorEndpoints endpoints = ActorEndpoints();
 
     with (endpoints) {
-      proxyUrl = json.checkKey!string("proxyUrl");
-      oauthAuthorizationEndpoint = json.checkKey!string("oauthAuthorizationEndpoint");
-      oauthTokenEndpoint = json.checkKey!string("oauthTokenEndpoint");
-      provideClientKey = json.checkKey!string("provideClientKey");
-      signClientKey = json.checkKey!string("signClientKey");
-      sharedInbox = json.checkKey!string("sharedInbox");
+      optional(json, "proxyUrl", proxyUrl);
+      optional(json, "oauthAuthorizationEndpoint", oauthAuthorizationEndpoint);
+      optional(json, "oauthTokenEndpoint", oauthTokenEndpoint);
+      optional(json, "provideClientKey", provideClientKey);
+      optional(json, "signClientKey", signClientKey);
+      optional(json, "sharedInbox", sharedInbox);
     }
 
     return endpoints;

source/util.d

@@ -3,18 +3,24 @@ module util;
 import std.format;
 import std.json;
 
-JSONValue requiredKey(string key)(JSONValue val) {
-  const(JSONValue)* j = key in val;
+void optional(T)(ref JSONValue val, string key, ref T receiver) {
+  const(JSONValue)* p = key in val;
 
-  if (j)
-    return *j;
+  if (p == null)
+    return;
 
-  throw new Exception(format("Key %s not found in json", key));
+  static if (is(JSONValue == T))
+    receiver = *p;
+  else
+    receiver = (*p).get!T;
 }
 
-T checkKey(T)(JSONValue val, string key) {
-  if (JSONValue* j = key in val)
-    return (*j).get!T;
-
-  return T.init;
+T optional(T)(ref JSONValue val, string key) {
+  T t;
+  optional(val, key, t);
+  return t;
+}
+
+void required(T)(ref JSONValue val, string key, ref T receiver) {
+  receiver = val[key].get!T;
 }