Django-CMS Custom plugin and placeholders

I'm really new to Django-CMS, I had a look at the docs but I can;'t find what I need so I could be probably doing it wrong. Anyway I'm creating a custom plugin, I have the model with 3 placeholders inside:

models.py

class Tile(CMSPlugin):
   text = PlaceholderField('text', related_name='tile_text')
   img = PlaceholderField('img', related_name='tile_img')
   link = PlaceholderField('link', related_name='tile_link')

then I have 3 different Plugins using the model:

cms_plugins.py

from cms.plugin_base import CMSPluginBase
from cms.models.pluginmodel import CMSPlugin
from cms.plugin_pool import plugin_pool
from django.utils.translation import ugettext_lazy as _

from tiles_plugin.models import Tile


class BigTilePlugin(CMSPluginBase):
    model = Tile
    name = _('Big Tile Plugin')
    render_template = 'tiles_plugin/big_tile.html'
    allow_children = True

    def render(self, context, instance, placeholder):
        context['instance'] = instance
        return context

class MedTilePlugin(CMSPluginBase):
    model = Tile
    name = _('Medium Tile Plugin')
    render_template = 'tiles_plugin/med_tile.html'
    allow_children = True

    def render(self, context, instance, placeholder):
        context['instance'] = instance
        return context

class SmallTilePlugin(CMSPluginBase):
    model = Tile
    name = _('Small Tile Plugin')
    render_template = 'tiles_plugin/small_tile.html'
    allow_children = True

    def render(self, context, instance, placeholder):
        context['instance'] = instance
        return context


plugin_pool.register_plugin(BigTilePlugin)
plugin_pool.register_plugin(MedTilePlugin)
plugin_pool.register_plugin(SmallTilePlugin)

and then I have the templates:

big_tile.html

{% load cms_tags %}
<div class="big-tile">
    <div class="content">
        {% render_placeholder instance.text %}
    </div>
    <div class="link">
        {% render_placeholder instance.link %}
    </div>
    <div class="img">
        {% render_placeholder instance.img %}
    </div>
</div>

And here it comes the problem, when I create the plugin and i insert inside the text/picture/link plugins, these are not populated so basically everything is empty, it's like the javascript is not populating it (for sure it's not the javascript) but I think I'm missing the relationship with the child_plugins. Can anyone help me out?

Thanks

EDIT

This made it work properly:

    {% for plugin in instance.child_plugin_instances %}
        {% render_plugin plugin %}
    {% endfor %}

Thanks to @mfcovington

Solution

It looks like almost everything is right. However, to get text, for example, you need to use instance.tile.text instead of instance.text.

So, your template should look something like this:

{% load cms_tags %}
<div class="big-tile">
    <div class="content">
        {% render_placeholder instance.tile.text %}
    </div>
    <div class="link">
        {% render_placeholder instance.tile.link %}
    </div>
    <div class="img">
        {% render_placeholder instance.tile.img %}
    </div>
</div>

Alternatively, when you set the context, you could set context['tile']:

class BigTilePlugin(CMSPluginBase):
    ...
    def render(self, context, instance, placeholder):
        context['tile'] = instance.tile
        return context

This would allow you to use tile.text, etc. instead of instance.tile.text, etc. in your template.

EDIT:

In case you are interested, besides your model info, there are lots of other things contained within instance. For example, in one of my cms_plugins.py files I added print(dir(instance)) within a CMSPlugin for a model called carousel and got the following output to my terminal (it will, of course differ from yours, but most things will be in common):

['DoesNotExist', 'Meta', 'MultipleObjectsReturned', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_base_manager', '_carousel_cache', '_check_column_name_clashes', '_check_field_name_clashes', '_check_fields', '_check_id_field', '_check_index_together', '_check_local_fields', '_check_m2m_through_same_relationship', '_check_managers', '_check_model', '_check_ordering', '_check_swappable', '_check_unique_together', '_db_connection', '_default_manager', '_deferred', '_do_insert', '_do_update', '_get_FIELD_display', '_get_basepath', '_get_children_path_interval', '_get_database_connection', '_get_database_cursor', '_get_lastpos_in_path', '_get_next_or_previous_by_FIELD', '_get_next_or_previous_in_order', '_get_parent_path_from_path', '_get_path', '_get_pk_val', '_get_serializable_model', '_get_unique_checks', '_inc_path', '_inst', '_int2str', '_meta', '_perform_date_checks', '_perform_unique_checks', '_placeholder_cache', '_prepare_pos_var', '_prepare_pos_var_for_add_sibling', '_prepare_pos_var_for_move', '_process_foreign_keys', '_render_meta', '_save_parents', '_save_table', '_set_pk_val', '_state', '_str2int', '_valid_pos_for_add_sibling', '_valid_pos_for_move', '_valid_pos_for_sorted_add_sibling', '_valid_pos_for_sorted_move', 'add_child', 'add_root', 'add_sibling', 'add_url', 'alias_reference', 'aliaspluginmodel', 'alphabet', 'carousel', 'carousel_id', 'carouselplugin', 'changed_date', 'check', 'child_plugin_instances', 'clean', 'clean_fields', 'cmsplugin_ptr', 'cmsplugin_ptr_id', 'cmsplugin_set', 'column', 'copy_plugin', 'copy_relations', 'copy_url', 'creation_date', 'date_error_message', 'delete', 'delete_url', 'depth', 'dump_bulk', 'edit_url', 'file', 'find_problems', 'fix_tree', 'flash', 'full_clean', 'gap', 'get_ancestors', 'get_annotated_list', 'get_breadcrumb', 'get_breadcrumb_json', 'get_children', 'get_children_count', 'get_database_vendor', 'get_depth', 'get_descendant_count', 'get_descendants', 'get_descendants_group_count', 'get_first_child', 'get_first_root_node', 'get_first_sibling', 'get_foreign_keys', 'get_instance_icon_alt', 'get_instance_icon_src', 'get_last_child', 'get_last_root_node', 'get_last_sibling', 'get_media_path', 'get_next_by_changed_date', 'get_next_by_creation_date', 'get_next_sibling', 'get_parent', 'get_plugin_class', 'get_plugin_class_instance', 'get_plugin_instance', 'get_plugin_name', 'get_position_in_placeholder', 'get_prev_sibling', 'get_previous_by_changed_date', 'get_previous_by_creation_date', 'get_root', 'get_root_nodes', 'get_short_description', 'get_siblings', 'get_sorted_pos_queryset', 'get_translatable_content', 'get_tree', 'googlemap', 'has_change_permission', 'id', 'inheritpageplaceholder', 'is_child_of', 'is_descendant_of', 'is_leaf', 'is_root', 'is_sibling_of', 'language', 'link', 'load_bulk', 'move', 'move_url', 'multicolumns', 'node_order_by', 'notify_on_autoadd', 'notify_on_autoadd_children', 'num_children', 'numchild', 'numconv_obj', 'numconv_obj_', 'objects', 'page', 'parent', 'parent_id', 'path', 'picture', 'pk', 'placeholder', 'placeholder_id', 'placeholderreference', 'plugin_type', 'position', 'post_copy', 'prepare_database_save', 'reload', 'render_plugin', 'save', 'save_base', 'serializable_value', 'set_base_attr', 'set_translatable_content', 'shinyapppluginmodel', 'steplen', 'teaser', 'text', 'translatable_content_excluded_fields', 'unique_error_message', 'validate_unique', 'video']