added template for list

templates/list.py

@@ -0,0 +1,52 @@
+from copy import deepcopy as copy
+from button import ButtonTemplate
+ButtonTemplate.get_buttons = lambda self: self.template['attachment']['payload']['buttons']
+
+TITLE_CHARACTER_LIMIT = 80
+SUBTITLE_CHARACTER_LIMIT = 80
+BUTTON_TITLE_CHARACTER_LIMIT = 20
+BUTTON_LIMIT = 3
+ELEMENTS_LIMIT = 4
+
+template = {
+    'template_type': 'list',
+    'value': {
+        'attachment': {
+            'type': 'template',
+            'payload': {
+                'template_type': 'list',
+                'top_element_style': 'compact',
+                'elements': []
+            }
+        }
+    }
+}
+
+
+class ListTemplate:
+    def __init__(self, top_element_style=''):
+        self.template = copy(template['value'])
+        self.elements = []
+        if top_element_style!= '':
+            self.template['attachment']['payload']['top_element_style'] = top_element_style
+
+    def add_element(self, title='', image_url='', subtitle='', buttons=[], default_action={}):
+        element = {}
+        element['title'] = title[:TITLE_CHARACTER_LIMIT]
+        # won't render without an image_url
+        element['image_url'] = image_url
+        if subtitle != '':
+            element['subtitle'] = subtitle[:SUBTITLE_CHARACTER_LIMIT]
+
+        for button in buttons:
+            button['title'] = button['title'][:BUTTON_TITLE_CHARACTER_LIMIT]
+        if len(buttons) > 0:
+            element['buttons'] = buttons[:BUTTON_LIMIT]
+        if len(default_action) > 0:
+            element['default_action'] = default_action
+        if len(self.elements) < ELEMENTS_LIMIT:
+            self.elements.append(element)
+
+    def get_message(self):
+        self.template['attachment']['payload']['elements'] = self.elements
+        return self.template