Allow dependencies between questions (#1202)

- [x] data model
- [x] api
- [x] backend editor
- [x] backend validation logic
- [x] frontend display logic
- [x] frontend validation logic
- [x] test checkout step
- [x] test modify order in frontend
- [x] test modify order in backend
- [x] validation tests
- [x] correctly evaluate dependency tree in frontend?
- [x] copy events

src/pretix/static/pretixcontrol/js/ui/main.js

@@ -1,13 +1,5 @@
 /*global $,gettext*/
 
-function question_page_toggle_view() {
-    var show = $("#id_type").val() == "C" || $("#id_type").val() == "M";
-    $("#answer-options").toggle(show);
-
-    show = $("#id_type").val() == "B" && $("#id_required").prop("checked");
-    $(".alert-required-boolean").toggle(show);
-}
-
 var waitingDialog = {
     show: function (message) {
         "use strict";
@@ -34,6 +26,26 @@ var ajaxErrDialog = {
     }
 };
 
+var apiGET = function (url, callback) {
+    $.getJSON(url, function (data) {
+        callback(data);
+    });
+};
+
+var i18nToString = function (i18nstring) {
+    var locale = $("body").attr("data-pretixlocale");
+    if (i18nstring[locale]) {
+        return i18nstring[locale];
+    } else if (i18nstring["en"]) {
+        return i18nstring["en"];
+    }
+    for (key in i18nstring) {
+        if (i18nstring[key]) {
+            return i18nstring[key];
+        }
+    }
+};
+
 $(document).ajaxError(function (event, jqXHR, settings, thrownError) {
     waitingDialog.hide();
     var c = $(jqXHR.responseText).filter('.container');
@@ -423,6 +435,9 @@ var form_handlers = function (el) {
             }
         );
     });
+
+    el.find("input[name*=question], select[name*=question]").change(questions_toggle_dependent);
+    questions_toggle_dependent();
 };
 
 $(function () {
@@ -491,14 +506,6 @@ $(function () {
         window.location.hash = e.target.hash;
     });
 
-    // Question editor
-    if ($("#answer-options").length) {
-
-        $("#id_type").change(question_page_toggle_view);
-        $("#id_required").change(question_page_toggle_view);
-        question_page_toggle_view();
-    }
-
     // Event wizard
     $("#event-slug-random-generate").click(function () {
         var url = $(this).attr("data-rng-url");