Can get the ID of a user from its email address

src/entities/RequestHandler.ts

@@ -209,6 +209,21 @@ export class RequestHandler {
 		return userID;
 	}
 
+	/**
+	 * Find user ID based on its email address, included in a POST request
+	 * 
+	 * @param name The name of the POST field containing the email address of the user
+	 */
+	public async postUserIdFromEmail(name: string) : Promise<number> {
+		const email = this.postEmail(name);
+		const userID = await AccountHelper.FindIDFromEmail(email);
+
+		if(userID < 1)
+			this.error(404, "Email not found!");
+		
+		return userID;
+	}
+
 	/**
 	 * Get a POST group ID
 	 * 

src/helpers/AccountHelper.ts

@@ -175,6 +175,24 @@ export class AccountHelper {
 		}) > 0;
 	}
 
+	/**
+	 * Find user ID from its email address
+	 * 
+	 * @param email Email address
+	 * @returns The ID of the matching user / -1 if none found
+	 */
+	public static async FindIDFromEmail(email: string) : Promise<number> {
+		const result = await DatabaseHelper.QueryRow({
+			table: USER_TABLE,
+			where: {
+				mail: email,
+			},
+			fields: ["ID"]
+		});
+
+		return result == null ? -1 : result.ID;
+	}
+
 
 	/**
 	 * Check out whether a virtual directory is available or not