Fix #277 -- Embeddable shop (#622)

* Vendor vue.js

* Refactor item_group_by_category to support vouchers

* Widget: Show product list

* Widget: free prices

* Widget: pictures and loading indicator

* Widget: First iframe steps

* Widget: Do not rerender iframe

* Widget: Error handling

* Improve widget

* Widget: localization tech

* Fix invoice style

* Voucher attribute and waiting list

* Add some iframe chrome

* First step to namespaced carts

* More isolation steps

* More cart isolation things

* More cart isolation things

* Mobile stuff

* Show cart on checkout pages

* PayPal and Stripe support

* Enable downloads

* Locale handling

* change text "save URL to this exact page"

* Widget: voucher redemption

* Widget: CSS

* CSS: Responsive

* Widget: CSS improvements

* Widget: Add embedding code generator

* Widget: Error messages and SSL check

* First tests

* Widget: tests

* Don't use IDs in widgets

* Widget: static files caching

src/pretix/control/forms/event.py

@@ -4,13 +4,13 @@ from django.core.exceptions import ValidationError
 from django.core.validators import RegexValidator
 from django.db.models import Q
 from django.utils.timezone import get_current_timezone_name
-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import pgettext_lazy, ugettext_lazy as _
 from i18nfield.forms import I18nFormField, I18nTextarea
 from pytz import common_timezones, timezone
 
 from pretix.base.forms import I18nModelForm, PlaceholderValidator, SettingsForm
 from pretix.base.models import Event, Organizer, TaxRule
-from pretix.base.models.event import EventMetaValue
+from pretix.base.models.event import EventMetaValue, SubEvent
 from pretix.base.reldate import RelativeDateField, RelativeDateTimeField
 from pretix.control.forms import (
     ExtFileField, SlugWidget, SplitDateTimePickerWidget,
@@ -897,3 +897,44 @@ class TaxRuleForm(I18nModelForm):
     class Meta:
         model = TaxRule
         fields = ['name', 'rate', 'price_includes_tax', 'eu_reverse_charge', 'home_country']
+
+
+class WidgetCodeForm(forms.Form):
+    subevent = forms.ModelChoiceField(
+        label=pgettext_lazy('subevent', "Date"),
+        required=True,
+        queryset=SubEvent.objects.none()
+    )
+    language = forms.ChoiceField(
+        label=_("Language"),
+        required=True,
+        choices=settings.LANGUAGES
+    )
+    voucher = forms.CharField(
+        label=_("Pre-selected voucher"),
+        required=False,
+        help_text=_("If set, the widget will show products as if this voucher has been entered and when a product is "
+                    "bought via the widget, this voucher will be used. This can for example be used to provide "
+                    "widgets that give discounts or unlock secret products.")
+    )
+
+    def __init__(self, *args, **kwargs):
+        self.event = kwargs.pop('event')
+        super().__init__(*args, **kwargs)
+
+        if self.event.has_subevents:
+            self.fields['subevent'].queryset = self.event.subevents.all()
+        else:
+            del self.fields['subevent']
+
+        self.fields['language'].choices = [(l, n) for l, n in settings.LANGUAGES if l in self.event.settings.locales]
+
+    def clean_voucher(self):
+        v = self.cleaned_data.get('voucher')
+        if not v:
+            return
+
+        if not self.event.vouchers.filter(code=v).exists():
+            raise ValidationError(_('The given voucher code does not exist.'))
+
+        return v

src/pretix/control/templates/pretixcontrol/event/settings_base.html

@@ -75,6 +75,11 @@
                     {% trans "Permissions" %}
                 </a>
             </li>
+            <li {% if "event.settings.widget" == url_name %}class="active"{% endif %}>
+                <a href="{% url 'control:event.settings.widget' organizer=request.event.organizer.slug event=request.event.slug %}">
+                    {% trans "Widget" %}
+                </a>
+            </li>
         {% endif %}
         {% for nav in nav_event_settings %}
             <li {% if nav.active %}class="active"{% endif %}>

src/pretix/control/templates/pretixcontrol/event/widget.html

@@ -0,0 +1,63 @@
+{% extends "pretixcontrol/event/settings_base.html" %}
+{% load i18n %}
+{% load staticfiles %}
+{% load bootstrap3 %}
+{% load eventurl %}
+{% block inside %}
+    <legend>{% trans "Widget" %}</legend>
+    <p>
+        {% blocktrans trimmed %}
+            The pretix widget is a way to embed your ticket shop into your event website. This way, your visitors can
+            buy their ticket right away without leaving your website.
+        {% endblocktrans %}
+    </p>
+    {% if valid %}
+        <p>
+            {% blocktrans trimmed %}
+                To embed the widget onto your website, simply copy the following code to the <code>&lt;head&gt;</code>
+                section of your website:
+            {% endblocktrans %}
+        </p>
+        <pre>&lt;link rel="stylesheet" type="text/css" href="{% abseventurl request.event "presale:event.widget.css" %}"&gt;
+&lt;script type="text/javascript" src="{{ urlprefix }}{% url "presale:widget.js" lang=form.cleaned_data.language %}" async&gt;&lt;/script&gt;</pre>
+        <p>
+            {% blocktrans trimmed %}
+                Then, copy the following code to the place of your website where you want the widget to show up:
+            {% endblocktrans %}
+        </p>
+        {% if form.cleaned_data.subevent %}
+            {% abseventurl request.event "presale:event.index" subevent=form.cleaned_data.subevent.pk as indexurl %}
+        {% else %}
+          {% abseventurl request.event "presale:event.index" as indexurl %}
+        {% endif %}
+        <pre>&lt;pretix-widget event="http://192.168.0.10:8000/democon/"{% if form.cleaned_data.subevent %} subevent="{{ form.cleaned_data.subevent.pk }}"{% endif %}{% if form.cleaned_data.voucher %} voucher="{{ form.cleaned_data.voucher }}"{% endif %}&gt;&lt;/pretix-widget&gt;
+&lt;noscript&gt;
+   &lt;div class="pretix-widget"&gt;
+        &lt;div class="pretix-widget-info-message"&gt;
+            {% blocktrans trimmed with a_attr='target="_blank" href="'|add:indexurl|add:'"'|safe %}
+                JavaScript is disabled in your browser. To access our ticket shop without javascript,
+                please &lt;a {{ a_attr }}&gt;click here&lt;/a&gt;.
+            {% endblocktrans %}
+        &lt;/div&gt;
+    &lt;/div&gt;
+&lt;/noscript&gt;
+</pre>
+    {% else %}
+        <p>
+            {% blocktrans trimmed %}
+                Using this form, you can generate a code to copy and paste to your website source.
+            {% endblocktrans %}
+        </p>
+        <form action="" method="post" class="form-horizontal">
+            {% csrf_token %}
+            {% bootstrap_form form layout="control" %}
+            <div class="form-group">
+                <div class="col-md-offset-3 col-md-9">
+                    <button type="submit" class="btn btn-primary btn-save">
+                        {% trans "Generate widget code" %}
+                    </button>
+                </div>
+            </div>
+        </form>
+    {% endif %}
+{% endblock %}

src/pretix/control/urls.py

@@ -75,6 +75,7 @@ urlpatterns = [
         url(r'^settings/tax/(?P<rule>\d+)/$', event.TaxUpdate.as_view(), name='event.settings.tax.edit'),
         url(r'^settings/tax/add$', event.TaxCreate.as_view(), name='event.settings.tax.add'),
         url(r'^settings/tax/(?P<rule>\d+)/delete$', event.TaxDelete.as_view(), name='event.settings.tax.delete'),
+        url(r'^settings/widget$', event.WidgetSettings.as_view(), name='event.settings.widget'),
         url(r'^subevents/$', subevents.SubEventList.as_view(), name='event.subevents'),
         url(r'^subevents/(?P<subevent>\d+)/$', subevents.SubEventUpdate.as_view(), name='event.subevent'),
         url(r'^subevents/(?P<subevent>\d+)/delete$', subevents.SubEventDelete.as_view(),

src/pretix/control/views/event.py

@@ -1,6 +1,7 @@
 import re
 from collections import OrderedDict
 from datetime import timedelta
+from urllib.parse import urlsplit
 
 from django.conf import settings
 from django.contrib import messages
@@ -36,10 +37,12 @@ from pretix.control.forms.event import (
     CommentForm, DisplaySettingsForm, EventMetaValueForm, EventSettingsForm,
     EventUpdateForm, InvoiceSettingsForm, MailSettingsForm,
     PaymentSettingsForm, ProviderForm, TaxRuleForm, TicketSettingsForm,
+    WidgetCodeForm,
 )
 from pretix.control.permissions import EventPermissionRequiredMixin
 from pretix.control.signals import nav_event_settings
 from pretix.helpers.urls import build_absolute_uri
+from pretix.multidomain.urlreverse import get_domain
 from pretix.presale.style import regenerate_css
 
 from . import CreateView, UpdateView
@@ -989,3 +992,31 @@ class TaxDelete(EventSettingsViewMixin, EventPermissionRequiredMixin, DeleteView
         context = super().get_context_data(*args, **kwargs)
         context['possible'] = self.object.allow_delete()
         return context
+
+
+class WidgetSettings(EventSettingsViewMixin, EventPermissionRequiredMixin, FormView):
+    template_name = 'pretixcontrol/event/widget.html'
+    permission = 'can_change_event_settings'
+    form_class = WidgetCodeForm
+
+    def get_form_kwargs(self):
+        kwargs = super().get_form_kwargs()
+        kwargs['event'] = self.request.event
+        return kwargs
+
+    def form_valid(self, form):
+        ctx = self.get_context_data()
+        ctx['form'] = form
+        ctx['valid'] = True
+        return self.render_to_response(ctx)
+
+    def get_context_data(self, **kwargs):
+        ctx = super().get_context_data(**kwargs)
+        ctx['urlprefix'] = settings.SITE_URL
+        domain = get_domain(self.request.organizer)
+        if domain:
+            siteurlsplit = urlsplit(settings.SITE_URL)
+            if siteurlsplit.port and siteurlsplit.port not in (80, 443):
+                domain = '%s:%d' % (domain, siteurlsplit.port)
+            ctx['urlprefix'] = '%s://%s' % (siteurlsplit.scheme, domain)
+        return ctx