Added introspection query for older GraphQL servers.

src/app/services/gql.service.ts

@@ -12,6 +12,8 @@ import 'rxjs/Rx';
 // TODO - Check if this is necessary
 import 'rxjs/add/observable/throw';
 
+import { oldIntrospectionQuery } from './oldIntrospectionQuery';
+
 @Injectable()
 export class GqlService {
   defaultHeaders = {
@@ -118,7 +120,17 @@ export class GqlService {
     return this.send(introspectionQuery).map(data => {
       console.log('introspection', data.data);
       return data.data;
-    }).do(() => this.api_url = currentApiUrl);
+    })
+    .catch((err) => {
+      console.log('Error from first introspection query.', err);
+
+      // Try the old introspection query
+      return this.send(oldIntrospectionQuery).map(data => {
+        console.log('old introspection', data.data);
+        return data.data;
+      });
+    })
+    .do(() => this.api_url = currentApiUrl);
   }
 
   getIntrospectionData() {

src/app/services/oldIntrospectionQuery.ts

@@ -0,0 +1,80 @@
+export const oldIntrospectionQuery = `
+
+  query IntrospectionQuery {
+    __schema {
+      queryType { name }
+      mutationType { name }
+      subscriptionType { name }
+      types {
+        ...FullType
+      }
+      directives {
+        name
+        description
+        args {
+          ...InputValue
+        }
+        onOperation
+        onFragment
+        onField
+      }
+    }
+  }
+
+  fragment FullType on __Type {
+    kind
+    name
+    description
+    fields(includeDeprecated: true) {
+      name
+      description
+      args {
+        ...InputValue
+      }
+      type {
+        ...TypeRef
+      }
+      isDeprecated
+      deprecationReason
+    }
+    inputFields {
+      ...InputValue
+    }
+    interfaces {
+      ...TypeRef
+    }
+    enumValues(includeDeprecated: true) {
+      name
+      description
+      isDeprecated
+      deprecationReason
+    }
+    possibleTypes {
+      ...TypeRef
+    }
+  }
+
+  fragment InputValue on __InputValue {
+    name
+    description
+    type { ...TypeRef }
+    defaultValue
+  }
+
+  fragment TypeRef on __Type {
+    kind
+    name
+    ofType {
+      kind
+      name
+      ofType {
+        kind
+        name
+        ofType {
+          kind
+          name
+        }
+      }
+    }
+  }
+`;