From df0578d2485f79c22da6ad828844f4d6dbabe78c Mon Sep 17 00:00:00 2001
From: Suraj Shetty <surajshetty3416@gmail.com>
Date: Wed, 7 Apr 2021 18:18:15 +0530
Subject: [PATCH 1/4] feat: Show language switcher for guest users on navbar

---
 frappe/templates/base.html                    | 31 ++++++++++++++++
 frappe/templates/includes/navbar/navbar.html  |  3 ++
 .../includes/navbar/navbar_items.html         |  8 ++---
 frappe/translate.py                           | 36 ++++++++++++++-----
 4 files changed, 66 insertions(+), 12 deletions(-)

diff --git a/frappe/templates/base.html b/frappe/templates/base.html
index c092e76485..ec78050e53 100644
--- a/frappe/templates/base.html
+++ b/frappe/templates/base.html
@@ -110,5 +110,36 @@
 	{%- endblock %}
 	<!-- csrf_token -->
 	{%- block body_include %}{{ body_include or "" }}{% endblock -%}
+	<script >
+		frappe.ready(() => {
+			if (frappe.session.user === 'Guest') {
+				frappe.call("frappe.translate.get_all_languages", {
+					with_language_name: true
+				}).then(res => {
+					let languages = res.message;
+					languages.forEach(language_doc => {
+						$("#language-switcher")
+							.append(
+								$("<option></option>")
+									.attr("value", language_doc.language_code)
+									.text(language_doc.language_name)
+							);
+					});
+					$("#language-switcher").removeClass('hide');
+					const language = localStorage.getItem('preferred-language');
+					$("#language-switcher").val(language || 'en');
+					$("#language-switcher").change((e) => {
+						let lang = $("#language-switcher").val();
+						localStorage.setItem('preferred-language', $("#language-switcher").val())
+						frappe.call("frappe.translate.set_preferred_language_cookie", {
+							"preferred_language": lang
+						}).then(() => {
+							window.location.reload();
+						});
+					});
+				});
+			}
+		})
+	</script>
 </body>
 </html>
diff --git a/frappe/templates/includes/navbar/navbar.html b/frappe/templates/includes/navbar/navbar.html
index 3ae0aef164..7856413602 100644
--- a/frappe/templates/includes/navbar/navbar.html
+++ b/frappe/templates/includes/navbar/navbar.html
@@ -21,5 +21,8 @@
 		<div class="collapse navbar-collapse" id="navbarSupportedContent">
 			{% include "templates/includes/navbar/navbar_items.html" %}
 		</div>
+		<div class="form-group mb-0">
+			<select class="form-control hide" id="language-switcher"></select>
+		</div>
 	</div>
 </nav>
diff --git a/frappe/templates/includes/navbar/navbar_items.html b/frappe/templates/includes/navbar/navbar_items.html
index 99b7b3aec4..34cc24fe1a 100644
--- a/frappe/templates/includes/navbar/navbar_items.html
+++ b/frappe/templates/includes/navbar/navbar_items.html
@@ -7,7 +7,7 @@
 <li class="nav-item dropdown {% if submenu %} dropdown-submenu {% endif %}">
 	<a class="nav-link dropdown-toggle" href="#" id="{{ dropdown_id }}" role="button"
 		data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
-		{{ item.label }}
+		{{ _(item.label) }}
 	</a>
   	<ul class="dropdown-menu" aria-labelledby="{{ dropdown_id }}">
 		{% for child in item.child_items %}
@@ -20,7 +20,7 @@
 <li class="dropdown {% if submenu %} dropdown-submenu {% endif %}">
 	<a class="dropdown-item dropdown-toggle" href="#" id="{{ dropdown_id }}" role="button"
 		data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
-		{{ item.label }}
+		{{ _(item.label) }}
 	</a>
 	<ul class="dropdown-menu" aria-labelledby="{{ dropdown_id }}">
 		{% for child in item.child_items %}
@@ -36,13 +36,13 @@
 <li class="nav-item">
 	<a class="nav-link" href="{{ (item.url or '')|abs_url }}"
 		{% if item.open_in_new_tab %} target="_blank" {% endif %}>
-		{{ item.label }}
+		{{ _(item.label) }}
 	</a>
 </li>
 {% else %}
 <a class="dropdown-item" href="{{ (item.url or '') | abs_url }}"
 	{% if item.open_in_new_tab %} target="_blank" {% endif %}>
-	{{ item.label }}
+	{{ _(item.label) }}
 </a>
 {% endif %}
 
diff --git a/frappe/translate.py b/frappe/translate.py
index b48884f4e8..cdcaa31920 100644
--- a/frappe/translate.py
+++ b/frappe/translate.py
@@ -21,6 +21,11 @@ import itertools, operator
 
 def guess_language(lang_list=None):
 	"""Set `frappe.local.lang` from HTTP headers at beginning of request"""
+	user_preferred_language = frappe.request.cookies.get('preferred_language')
+	is_guest_user = not frappe.session.user or frappe.session.user == 'Guest'
+	if is_guest_user and user_preferred_language:
+		return user_preferred_language
+
 	lang_codes = frappe.request.accept_languages.values()
 	if not lang_codes:
 		return frappe.local.lang
@@ -77,14 +82,6 @@ def set_default_language(lang):
 		frappe.db.set_default("lang", lang)
 	frappe.local.lang = lang
 
-def get_all_languages():
-	"""Returns all language codes ar, ch etc"""
-	def _get():
-		if not frappe.db:
-			frappe.connect()
-		return frappe.db.sql_list('select name from tabLanguage')
-	return frappe.cache().get_value('languages', _get)
-
 def get_lang_dict():
 	"""Returns all languages in dict format, full name is the key e.g. `{"english":"en"}`"""
 	return dict(frappe.db.sql('select language_name, name from tabLanguage'))
@@ -244,6 +241,8 @@ def get_translation_dict_from_file(path, lang, app):
 	return translation_map
 
 def get_user_translations(lang):
+	if not frappe.db:
+		frappe.connect()
 	out = frappe.cache().hget('lang_user_translations', lang)
 	if out is None:
 		out = {}
@@ -813,3 +812,24 @@ def get_contribution_status(message_id):
 
 def get_translator_url():
 	return frappe.get_hooks()['translator_url'][0]
+
+@frappe.whitelist(allow_guest=True)
+def get_all_languages(with_language_name=False):
+	"""Returns all language codes ar, ch etc"""
+	def get_language_codes():
+		return frappe.db.sql_list('select name from tabLanguage')
+
+	def get_all_language_with_name():
+		return frappe.db.get_all('language', ['language_code', 'language_name'])
+
+	if not frappe.db:
+		frappe.connect()
+
+	if with_language_name:
+		return frappe.cache().get_value('languages_with_name', get_all_language_with_name)
+	else:
+		return frappe.cache().get_value('languages', get_language_codes)
+
+@frappe.whitelist(allow_guest=True)
+def set_preferred_language_cookie(preferred_language):
+	frappe.local.cookie_manager.set_cookie("preferred_language", preferred_language)

From fe6b427fb2ca6e9c03c6c201f9d111afef5cfaec Mon Sep 17 00:00:00 2001
From: Suraj Shetty <surajshetty3416@gmail.com>
Date: Wed, 7 Apr 2021 18:49:55 +0530
Subject: [PATCH 2/4] fix: Set lang attribute of document

---
 frappe/templates/base.html | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/frappe/templates/base.html b/frappe/templates/base.html
index ec78050e53..85f0510993 100644
--- a/frappe/templates/base.html
+++ b/frappe/templates/base.html
@@ -126,8 +126,9 @@
 							);
 					});
 					$("#language-switcher").removeClass('hide');
-					const language = localStorage.getItem('preferred-language');
-					$("#language-switcher").val(language || 'en');
+					const language = localStorage.getItem('preferred-language') || 'en';
+					$("#language-switcher").val(language);
+					document.documentElement.lang = language;
 					$("#language-switcher").change((e) => {
 						let lang = $("#language-switcher").val();
 						localStorage.setItem('preferred-language', $("#language-switcher").val())

From 7e1638ef600a4e87cffd3d7cf8fb3cacb9c1ec2c Mon Sep 17 00:00:00 2001
From: Suraj Shetty <surajshetty3416@gmail.com>
Date: Thu, 8 Apr 2021 09:46:07 +0530
Subject: [PATCH 3/4] fix: Only use cookie to remember lang preference

---
 frappe/templates/base.html | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/frappe/templates/base.html b/frappe/templates/base.html
index 85f0510993..d653006dcc 100644
--- a/frappe/templates/base.html
+++ b/frappe/templates/base.html
@@ -110,7 +110,7 @@
 	{%- endblock %}
 	<!-- csrf_token -->
 	{%- block body_include %}{{ body_include or "" }}{% endblock -%}
-	<script >
+	<script>
 		frappe.ready(() => {
 			if (frappe.session.user === 'Guest') {
 				frappe.call("frappe.translate.get_all_languages", {
@@ -126,12 +126,11 @@
 							);
 					});
 					$("#language-switcher").removeClass('hide');
-					const language = localStorage.getItem('preferred-language') || 'en';
+					const language = frappe.get_cookie('preferred_language') || 'en';
 					$("#language-switcher").val(language);
 					document.documentElement.lang = language;
 					$("#language-switcher").change((e) => {
 						let lang = $("#language-switcher").val();
-						localStorage.setItem('preferred-language', $("#language-switcher").val())
 						frappe.call("frappe.translate.set_preferred_language_cookie", {
 							"preferred_language": lang
 						}).then(() => {

From b41c5b59d329adf84f734d3a25b869efebdf9660 Mon Sep 17 00:00:00 2001
From: Suraj Shetty <surajshetty3416@gmail.com>
Date: Thu, 8 Apr 2021 12:39:23 +0530
Subject: [PATCH 4/4] feat: Use navigator.language for initial guess

---
 frappe/templates/base.html | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/frappe/templates/base.html b/frappe/templates/base.html
index d653006dcc..a00592f743 100644
--- a/frappe/templates/base.html
+++ b/frappe/templates/base.html
@@ -116,8 +116,11 @@
 				frappe.call("frappe.translate.get_all_languages", {
 					with_language_name: true
 				}).then(res => {
-					let languages = res.message;
-					languages.forEach(language_doc => {
+					let language_list = res.message;
+					let language = frappe.get_cookie('preferred_language');
+					let language_codes = [];
+					language_list.forEach(language_doc => {
+						language_codes.push(language_doc.language_code)
 						$("#language-switcher")
 							.append(
 								$("<option></option>")
@@ -126,7 +129,7 @@
 							);
 					});
 					$("#language-switcher").removeClass('hide');
-					const language = frappe.get_cookie('preferred_language') || 'en';
+					language = language || language_codes.includes(navigator.language) ? navigator.language : 'en';
 					$("#language-switcher").val(language);
 					document.documentElement.lang = language;
 					$("#language-switcher").change((e) => {