Fix & improve marking speakers as arrived

* Adjust for switch to POST by pretalx, see:
  pretalx/pretalx@d038075b5
* Handle CSRF protection
* Deal with pretalx's default handling of form submission buttons
* Fix typo that broke error handling
* Use JS strict mode, just because

Author: F30

src/samaware/static/samaware/samaware.js

@@ -1,3 +1,5 @@
+'use strict'
+
 document.addEventListener('DOMContentLoaded', () => {
 
     document.querySelectorAll('.samaware-list-filter input[type="checkbox"]').forEach((checkbox) => {
@@ -7,12 +9,21 @@ document.addEventListener('DOMContentLoaded', () => {
     })
 
     document.querySelectorAll('form.samaware-arrived-form').forEach((form) => {
+        // Save original contents of the buttons, as JS from pretalx itself will modify them upon submission
+        const buttonContents = new Map()
+        form.querySelectorAll('.samaware-btn').forEach((button) => {
+            buttonContents.set(button, button.innerHTML)
+        })
+
         form.addEventListener('submit', async (ev) => {
             ev.preventDefault()
 
             if (await toggleArrived(form)) {
                 form.querySelectorAll('.samaware-btn').forEach((button) => {
                     button.classList.toggle('d-none')
+                    // Undo modifications performed by pretalx JS
+                    button.classList.remove('disabled')
+                    button.innerHTML = buttonContents.get(button)
                 })
             }
         })
@@ -24,8 +35,11 @@ document.addEventListener('DOMContentLoaded', () => {
 async function toggleArrived(form) {
 
     try {
-        const response = await fetch(form.action)
-        if (response.staus >= 400) {
+        const response = await fetch(form.action, {
+            method: 'POST',
+            body: new FormData(form)
+        })
+        if (response.status >= 400) {
             return false
         }
         return true

src/samaware/templates/samaware/talk_overview.html

@@ -191,7 +191,8 @@ <h3>{% translate 'Contact' %}</h3>
                 <a href="mailto:{{ speaker.email }}">{{ speaker.email }}</a>
 
                 <h3>{% translate 'Attendance' %}</h3>
-                <form action="{% url 'orga:speakers.arrived' event=submission.event.slug code=speaker.code %}" method="GET" class="samaware-arrived-form">
+                <form action="{% url 'orga:speakers.arrived' event=submission.event.slug code=speaker.code %}" method="POST" class="samaware-arrived-form">
+                    {% csrf_token %}
                     {% if speaker_profile.has_arrived %}
                     <button type="submit" class="samaware-btn btn btn-sm btn-info d-none">{% translate 'Mark as arrived' %}</button>
                     <button type="submit" class="samaware-btn btn btn-sm btn-success">{% blocktranslate %}Mark as <strong>not</strong> arrived{% endblocktranslate %}</button>