From a4638be144e7aefd3cd147013920068aea41be84 Mon Sep 17 00:00:00 2001
From: Baptiste Jonglez <git@bitsofnetworks.org>
Date: Thu, 21 May 2020 15:03:17 +0200
Subject: [PATCH] Simplify send_email(): don't flash messages within this
 function

Since we have only three places that call send_email() and already several
special cases, it's simpler to just check the return value and flash
messages within the calling code.
---
 ihatemoney/utils.py | 14 ++++--------
 ihatemoney/web.py   | 53 +++++++++++++++++++++++++--------------------
 2 files changed, 34 insertions(+), 33 deletions(-)

diff --git a/ihatemoney/utils.py b/ihatemoney/utils.py
index f6fab922..bc3f32b2 100644
--- a/ihatemoney/utils.py
+++ b/ihatemoney/utils.py
@@ -11,7 +11,7 @@ from io import BytesIO, StringIO
 
 import jinja2
 from json import dumps, JSONEncoder
-from flask import flash, redirect, current_app, render_template
+from flask import redirect, current_app, render_template
 from flask_babel import get_locale
 from babel import Locale
 from werkzeug.routing import HTTPException, RoutingException
@@ -36,12 +36,10 @@ def slugify(value):
     return re.sub(r'[-\s]+', '-', value)
 
 
-def send_email(mail_message, flash_success="", flash_error=""):
-    """Send an email using Flask-Mail, returning False if there was an error.
+def send_email(mail_message):
+    """Send an email using Flask-Mail, with proper error handling.
 
-    Optionally display a "flash alert" message to the user.  The flash
-    message is different depending on whether we could successfully send
-    the email or not.
+    Return True if everything went well, and False if there was an error.
     """
     # Since Python 3.4, SMTPException and socket.error are actually
     # identical, but this was not the case before.  Also, it is more clear
@@ -49,12 +47,8 @@ def send_email(mail_message, flash_success="", flash_error=""):
     try:
         current_app.mail.send(mail_message)
     except (smtplib.SMTPException, socket.error):
-        if flash_error:
-            flash(flash_error, category="danger")
         return False
     # Email was sent successfully
-    if flash_success:
-        flash(flash_success, category="success")
     return True
 
 
diff --git a/ihatemoney/web.py b/ihatemoney/web.py
index 63d4fd71..312a4cb8 100644
--- a/ihatemoney/web.py
+++ b/ihatemoney/web.py
@@ -247,8 +247,12 @@ def create_project():
             msg = Message(message_title,
                           body=message_body,
                           recipients=[project.contact_email])
-            success = send_email(msg, _("A reminder email has just been sent to you"))
-            if not success:
+            success = send_email(msg)
+            if success:
+                flash(
+                    _("A reminder email has just been sent to you"), category="success"
+                )
+            else:
                 # Display the error as a simple "info" alert, because it's
                 # not critical and doesn't prevent using the project.
                 flash(
@@ -279,19 +283,20 @@ def remind_password():
                 body=render_localized_template("password_reminder", project=project),
                 recipients=[project.contact_email],
             )
-            success = send_email(
-                remind_message,
-                "",
-                _(
-                    "Sorry, there was an error while sending you an email "
-                    "with password reset instructions. "
-                    "Please check the email configuration of the server "
-                    "or contact the administrator."
-                ),
-            )
+            success = send_email(remind_message)
             if success:
                 return redirect(url_for(".password_reminder_sent"))
-
+            else:
+                flash(
+                    _(
+                        "Sorry, there was an error while sending you an email "
+                        "with password reset instructions. "
+                        "Please check the email configuration of the server "
+                        "or contact the administrator."
+                    ),
+                    category="danger",
+                )
+                # Fall-through: we stay on the same page and display the form again
     return render_template("password_reminder.html", form=form)
 
 
@@ -422,18 +427,20 @@ def invite():
                           body=message_body,
                           recipients=[email.strip()
                                       for email in form.emails.data.split(",")])
-            success = send_email(
-                msg,
-                _("Your invitations have been sent"),
-                _(
-                    "Sorry, there was an error while trying to send the invitation emails. "
-                    "Please check the email configuration of the server "
-                    "or contact the administrator."
-                ),
-            )
+            success = send_email(msg)
             if success:
+                flash(_("Your invitations have been sent"), category="success")
                 return redirect(url_for(".list_bills"))
-
+            else:
+                flash(
+                    _(
+                        "Sorry, there was an error while trying to send the invitation emails. "
+                        "Please check the email configuration of the server "
+                        "or contact the administrator."
+                    ),
+                    category="danger",
+                )
+                # Fall-through: we stay on the same page and display the form again
     return render_template("send_invites.html", form=form)