Add the posibility to change the username

cps/admin.py

@@ -35,7 +35,7 @@ from flask_login import login_required, current_user, logout_user
 from flask_babel import gettext as _
 from sqlalchemy import and_
 from sqlalchemy.exc import IntegrityError
-from sqlalchemy.sql.expression import func
+from sqlalchemy.sql.expression import func, exists
 from werkzeug.security import generate_password_hash
 
 from . import constants, logger, helper, services
@@ -563,7 +563,6 @@ def edit_user(user_id):
         else:
             if "password" in to_save and to_save["password"]:
                 content.password = generate_password_hash(to_save["password"])
-
             anonymous = content.is_anonymous
             content.role = constants.selected_roles(to_save)
             if anonymous:
@@ -601,6 +600,22 @@ def edit_user(user_id):
                     return render_title_template("user_edit.html", translations=translations, languages=languages,
                                                  new_user=0, content=content, downloads=downloads, registered_oauth=oauth_check,
                                                  title=_(u"Edit User %(nick)s", nick=content.nickname), page="edituser")
+            if "nickname" in to_save and to_save["nickname"] != content.nickname:
+                existing_nickname = ub.session.query(exists().where(
+                    ub.User.nickname == to_save["nickname"])).scalar()
+                if not existing_nickname:
+                    content.nickname = to_save["nickname"]
+                else:
+                    flash(_(u"This username is already taken."), category="error")
+                    return render_title_template("user_edit.html",
+                                                 translations=translations,
+                                                 languages=languages,
+                                                 new_user=0, content=content,
+                                                 downloads=downloads,
+                                                 registered_oauth=oauth_check,
+                                                 title=_(u"Edit User %(nick)s",
+                                                         nick=content.nickname),
+                                                 page="edituser")
 
             if "kindle_mail" in to_save and to_save["kindle_mail"] != content.kindle_mail:
                 content.kindle_mail = to_save["kindle_mail"]

cps/templates/user_edit.html

@@ -3,7 +3,7 @@
 <div class="discover">
   <h1>{{title}}</h1>
   <form role="form" method="POST" autocomplete="off">
-    {% if g.user and g.user.role_admin() and new_user %}
+    {% if g.user or g.user.role_admin() or new_user %}
     <div class="form-group required">
       <label for="nickname">{{_('Username')}}</label>
       <input type="text" class="form-control" name="nickname" id="nickname" value="{{ content.nickname if content.nickname != None }}" autocomplete="off">

cps/ub.py

@@ -27,6 +27,7 @@ from flask import g
 from flask_babel import gettext as _
 from flask_login import AnonymousUserMixin
 from werkzeug.local import LocalProxy
+
 try:
     from flask_dance.consumer.backend.sqla import OAuthConsumerMixin
     oauth_support = True

cps/web.py

@@ -38,7 +38,8 @@ from flask import render_template, request, redirect, send_from_directory, make_
 from flask_babel import gettext as _
 from flask_login import login_user, logout_user, login_required, current_user
 from sqlalchemy.exc import IntegrityError
-from sqlalchemy.sql.expression import text, func, true, false, not_, and_
+from sqlalchemy.sql.expression import text, func, true, false, not_, and_, \
+    exists
 from werkzeug.exceptions import default_exceptions
 from werkzeug.datastructures import Headers
 from werkzeug.security import generate_password_hash, check_password_hash
@@ -1252,6 +1253,22 @@ def profile():
                 return render_title_template("user_edit.html", content=current_user, downloads=downloads,
                                              title=_(u"%(name)s's profile", name=current_user.nickname), page="me",
                                              registered_oauth=oauth_check, oauth_status=oauth_status)
+        if "nickname" in to_save and to_save["nickname"] != current_user.nickname:
+            existing_nickname = ub.session.query(exists().where(
+                ub.User.nickname == to_save["nickname"])).scalar()
+            if not existing_nickname:
+                current_user.nickname = to_save["nickname"]
+            else:
+                flash(_(u"This username is already taken."), category="error")
+                return render_title_template("user_edit.html",
+                                             translations=translations,
+                                             languages=languages,
+                                             new_user=0, content=current_user,
+                                             downloads=downloads,
+                                             registered_oauth=oauth_check,
+                                             title=_(u"Edit User %(nick)s",
+                                                     nick=current_user.nickname),
+                                             page="edituser")
             current_user.email = to_save["email"]
         if "show_random" in to_save and to_save["show_random"] == "on":
             current_user.random_books = 1