tutorial 2, adding edit function

app.py

@@ -77,4 +77,35 @@ def undo(id):
      conn.execute('UPDATE items SET done = 0 WHERE id = ?', (id,))
      conn.commit()
      conn.close()
-     return redirect(url_for('index'))
+     return redirect(url_for('index'))
+
+
+@app.route('/<int:id>/edit/', methods=('GET','POST'))
+def edit(id):
+    conn = get_db_connection()
+
+    todo = conn.execute('SELECT i.id, i.list_id, i.done, i.content, l.title \
+                         FROM items i JOIN lists l \
+                         ON i.list_id = l.id WHERE i.id = ?', (id,)).fetchone()
+
+    lists = conn.execute('SELECT title FROM lists;').fetchall()
+
+    if request.method == 'POST':
+        content = request.form['content']
+        list_title = request.form['list']
+    
+        if not content:
+            flash('Content is required!')
+            return redirect(url_for('edit', id=id))
+
+        list_id = conn.execute('SELECT id FROM lists WHERE title = (?);',
+                                (list_title,)).fetchone()['id']
+
+        conn.execute('UPDATE items SET content = ?, list_id = ? \
+                    WHERE id = ?',
+                    (content, list_id, id))
+        conn.commit()
+        conn.close()
+        return redirect(url_for('index'))
+
+    return render_template('edit.html', todo=todo, lists=lists)

templates/edit.html

@@ -0,0 +1,41 @@
+{% extends 'base.html' %}
+
+{% block content %}
+
+<h1>{% block title %} Edit an Item {% endblock %}</h1>
+
+<form method="post">
+    <div class="form-group">
+        <label for="content">Content</label>
+        <input type="text" name="content"
+               placeholder="Todo content" class="form-control"
+               value="{{ todo['content'] or request.form['content'] }}"></input>
+    </div>
+
+    <div class="form-group">
+        <label for="list">List</label>
+        <select class="form-control" name="list">
+            {% for list in lists %}
+                {% if list['title'] == request.form['list'] %}
+                    <option value="{{ request.form['list'] }}" selected>
+                        {{ request.form['list'] }}
+                    </option>
+
+                {% elif list['title'] == todo['title'] %}
+                    <option value="{{ todo['title'] }}" selected>
+                        {{ todo['title'] }}
+                    </option>
+
+                {% else %}
+                    <option value="{{ list['title'] }}">
+                        {{ list['title'] }}
+                    </option>
+                {% endif %}
+            {% endfor %}
+        </select>
+    </div>
+    <div class="form-group">
+        <button type="submit" class="btn btn-primary">Submit</button>
+    </div>
+</form>
+{% endblock %}

templates/index.html

@@ -33,6 +33,10 @@
                                     class="btn btn-success btn-sm">
                             </form>
                         </div>
+                        <div class="col-12 col-md-3">
+                            <a class="btn btn-warning btn-sm"
+                            href="{{ url_for('edit', id=item['id']) }}">Edit</a>
+                        </div>
                     </div>
                     </li>
                 {% endfor %}