From 6d29267ef84e2b54acfd947532107c4eb06f0e00 Mon Sep 17 00:00:00 2001
From: Tom Hubrecht <tom.hubrecht@ens.fr>
Date: Tue, 20 Apr 2021 10:00:03 +0200
Subject: [PATCH] =?UTF-8?q?On=20rajoute=20un=20formulaire=20drag=20&=20dro?=
 =?UTF-8?q?p=20pour=20les=20votes=20=C3=A0=20classement?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 elections/templates/elections/vote/rank.html | 183 +++++++++++++++++--
 elections/views.py                           |   1 +
 2 files changed, 173 insertions(+), 11 deletions(-)

diff --git a/elections/templates/elections/vote/rank.html b/elections/templates/elections/vote/rank.html
index 556343d..f9baa49 100644
--- a/elections/templates/elections/vote/rank.html
+++ b/elections/templates/elections/vote/rank.html
@@ -4,29 +4,105 @@
 
 {% block extra_head %}
 <script>
+  const nb_options = {{ nb_options }};
+  var ranks_used = 1;
+  var rank_zones = new Array(nb_options + 1);
+  var ranked = 0;
+
+  function getLabelText($input) {
+    var label = $input.closest('.field').querySelector('.label label').innerHTML;
+    return label.substring(0, label.length - 1).trim();
+  }
+
+  // Fonction auxilliaires gérant le drag & drop
+  function dragstart_handler(event) {
+    event.dataTransfer.setData('text/plain', event.target.id);
+  }
+
+  function dragover_handler(event) {
+    event.preventDefault();
+    event.dataTransfer.dropEffect = 'move';
+  }
+
+  function drop_handler(event) {
+    event.preventDefault();
+    // On récupère l'id de la tuile à déplacer
+    const data = event.dataTransfer.getData('text/plain');
+
+    var $target = event.target.closest('.drop-zone');
+
+    if ($target.id == 'rank-add') {
+      ranks_used += 1;
+
+      // Si on a autant de rangs que d'option, on cache le bouton +
+      if (ranks_used == nb_options) {
+        $target.parentElement.classList.add('is-hidden');
+      }
+
+      $target = rank_zones[ranks_used];
+      $target.parentElement.classList.remove('is-hidden');
+    }
+
+    // On déplace l'option
+    var $tile = document.getElementById(data);
+    $target.appendChild($tile);
+
+    // On enregistre le rang dans le formulaire
+    const rank = $target.dataset.rank;
+    var $input = document.getElementById($tile.dataset.input);
+    $input.value = rank;
+
+    // On modifie ranked pour savoir combien d'option on a classé
+    ranked += ($target.id == 'unranked' ? -1 : 1);
+
+    // On décale pour éviter les rangs vides
+    for (let i = 1; i <= ranks_used && i < nb_options; i++) {
+      // On a au moins le tag avec le numéro du rang
+      if (rank_zones[i].childElementCount == 1) {
+        while (rank_zones[i + 1].childElementCount > 1) {
+          let $tile = rank_zones[i + 1].lastChild;
+          let $input = document.getElementById($tile.dataset.input);
+          $input.value = i.toString();
+          rank_zones[i].append($tile);
+        }
+      }
+    }
+
+    // On cache la dernière zone si elle est vide, mias on garde au moins la première
+    if (ranks_used > 1 && rank_zones[ranks_used].childElementCount == 1) {
+      // On affiche le bouton + si besoin
+      if (ranks_used == nb_options) {
+        let $add_rank = document.getElementById('rank-add');
+        $add_rank.parentElement.classList.remove('is-hidden')
+      }
+
+      rank_zones[ranks_used].parentElement.classList.add('is-hidden');
+      ranks_used -= 1;
+    }
+  }
+
   document.addEventListener('DOMContentLoaded', () => {
+    // Affiche le modal et remplit le récapitulatif
     document.getElementById('confirm-button').addEventListener('click', () => {
       var $modal_body = document.getElementById('modal-body');
 
-      var ranks = new Array({{ nb_options }} + 1);
+      var ranks = new Array(nb_options + 1);
 
       (document.querySelectorAll('.control .input') || []).forEach($input => {
-        var rank = parseInt($input.value);
-        if ($input.value == '') {
-          rank = {{ nb_options }};
-        }
+        var rank = parseInt($input.value) || nb_options;
 
-        var option = $input.closest('.field').querySelector('.label label').innerHTML;
-        option = option.substring(0, option.length - 1).trim();
+        var option = getLabelText($input)
 
-        if (rank > 0 && rank <= {{ nb_options }}) {
-          ranks[rank] = (ranks[rank] || []).concat([option]); // TODO: chercher une meilleure méthode
+        if (rank > 0 && rank <= nb_options) {
+          ranks[rank] = (ranks[rank] || []).concat([option]);
+        } else {
+          ranks[nb_options] = (ranks[nb_options] || []).concat([option]);
         }
       });
 
       var table_rows = '';
 
-      for (let i = 1; i <= {{ nb_options }}; i++) {
+      for (let i = 1; i <= nb_options; i++) {
         var option_list = '';
 
         if (!(typeof ranks[i] === 'undefined')) {
@@ -49,7 +125,55 @@
           ${table_rows}
         </tbody>
       </table>`;
+    });
 
+    // Change le mode de remplissge de formulaire (input vs drag & drop)
+    document.getElementById('change-method').addEventListener('click', () => {
+      var $hide = document.getElementById('hide-form');
+      var $drag_zone = document.getElementById('drag-zone');
+      var $method_button = document.getElementById('change-method');
+
+      // On échange ce qui est visible
+      $hide.classList.toggle('is-hidden');
+      $drag_zone.classList.toggle('is-hidden');
+
+      if ($hide.classList.contains('is-hidden')) {
+        $method_button.innerHTML = "{% trans "Utiliser le formulaire classique" %}";
+      } else {
+        $method_button.innerHTML = "{% trans "Utiliser le cliquer-déposer" %}";
+      }
+    });
+
+    // Initialise les éléments pour le formulaire interactif
+    var $unranked = document.getElementById('unranked');
+
+    for (let i = 1; i <= nb_options; i++) {
+      rank_zones[i] = document.getElementById(`rank-${i}`);
+    }
+
+    (document.querySelectorAll('.control .input') || []).forEach($input => {
+      var option = getLabelText($input);
+
+      // On créé une tuile avec le nom de l'option
+      var $tile = document.createElement('div');
+
+      $tile.classList.add('tile', 'is-parent', 'is-flex-grow-0');
+      $tile.id = `tile-${$input.id}`;
+      $tile.dataset.input = $input.id;
+      $tile.innerHTML = `<p class="tile is-child notification is-primary">${option}</p>`;
+
+      $tile.setAttribute('draggable', true);
+      $tile.addEventListener('dragstart', dragstart_handler);
+
+      // On rajoute la tuile dans le classement ou dans les non classées
+      const rank = parseInt($input.value);
+      if (!(typeof rank === 'undefined') && rank > 0 && rank <= nb_options) {
+        rank_zones[rank].appendChild($tile);
+      } else {
+        $unranked.appendChild($tile);
+        // On enlève les valeurs non règlementaires
+        $input.value = '';
+      }
     });
   });
 
@@ -58,5 +182,42 @@
 
 
 {% block vote_form %}
-{% include "forms/formset.html" %}
+<div class="tile is-ancestor">
+  <div class="tile is-parent">
+    <a id="change-method" class="tile is-child notification has-text-centered is-size-5 is-primary">
+      {% trans "Utiliser le formulaire classique" %}
+    </a>
+  </div>
+</div>
+
+<div id="drag-zone" class="tile is-ancestor">
+  <div class="tile is-vertical">
+    {% for i in range_options %}
+    <div class="tile is-parent is-flex-grow-0 {% if not forloop.first %}is-hidden{% endif %}" ondrop="drop_handler(event)" ondragover="dragover_handler(event)">
+      <div id="rank-{{ i }}" class="tile is-child notification is-primary is-light pl-3 pt-3 drop-zone" data-rank="{{ i }}">
+        <div class="tag is-medium is-primary">{% blocktrans %}Rang {{ i }}{% endblocktrans %}</div>
+      </div>
+    </div>
+    {% endfor %}
+
+    <div class="tile is-parent is-flex-grow-0" ondrop="drop_handler(event)" ondragover="dragover_handler(event)">
+      <div id="rank-add" class="tile is-child notification has-text-centered drop-zone">
+        <span class="icon-text subtitle has-text-primary">
+          <span class="icon">
+            <i class="fas fa-plus"></i>
+          </span>
+          <span>{% trans "Ajouter un rang" %}</span>
+        </span>
+      </div>
+    </div>
+  </div>
+
+  <div id="unranked" class="tile is-vertical drop-zone" ondrop="drop_handler(event)" ondragover="dragover_handler(event)" data-rank="">
+  </div>
+</div>
+
+<div id="hide-form" class="block is-hidden">
+  {% include "forms/formset.html" %}
+</div>
+
 {% endblock %}
diff --git a/elections/views.py b/elections/views.py
index 46863d9..b39238b 100644
--- a/elections/views.py
+++ b/elections/views.py
@@ -529,6 +529,7 @@ class VoteView(OpenElectionOnlyMixin, DetailView):
         context["q_index"] = questions.index(self.object) + 1
         context["q_total"] = len(questions)
         context["nb_options"] = self.object.options.count()
+        context["range_options"] = range(1, context["nb_options"] + 1)
         context["vote_rule"] = VOTE_RULES[self.object.type].format(**context)
         return context