CKAN Templates Tutorial 5(v2.9): Template helper functions

http://docs.ckan.org/en/2.9/theming/templates.html#template-helper-functions

若要讀出 CKAN 裡的資訊，template helper function 是方法之一。

內建的 template helper functions

延續 上個 CKAN templates Tutorial，將 example_theme 底下的 templates/home/layout1.html 修改如下：

{% ckan_extends %}

{% block featured_group %}

<p>recently_changed_packages_activity_stream</p>

    <ul>

        {% for stream in h.recently_changed_packages_activity_stream(limit=4) %}

            <li>stream id: {{ stream.id }}</li>

        {% endfor %}

    </ul>

{% endblock %}

以 h 開頭的 h.recently_changed_packages_activity_stream，便是 template helper function，可讀出最近資料集(package)的更新資訊 ，結果如下：

在 templates 裡可透過 h 全域變數呼叫 ckan.lib.helpers 底下的 template helper function。參考：Template helper functions reference。

自訂 template helper functions

實作 ckan.plugins.interfaces.ITemplateHelpers，列出最受歡迎的 group。

修改 plugin.py 

import ckan.plugins as plugins

import ckan.plugins.toolkit as toolkit

def most_popular_groups():

    '''Return a sorted list of the groups with the most datasets.'''

    # Get a list of all the site's groups from CKAN, sorted by number of

    # datasets.

    groups = toolkit.get_action('group_list')(

        data_dict={'sort': 'package_count desc', 'all_fields': True})

    # Truncate the list to the 10 most popular groups only.

    groups = groups[:10]

    return groups

class ExampleThemePlugin(plugins.SingletonPlugin):

    '''An example theme plugin.

    '''

    plugins.implements(plugins.IConfigurer)

    # Declare that this plugin will implement ITemplateHelpers.

    plugins.implements(plugins.ITemplateHelpers)

    def update_config(self, config):

        # Add this plugin's templates dir to CKAN's extra_template_paths, so

        # that CKAN will use this plugin's custom templates.

        toolkit.add_template_directory(config, 'templates')

    def get_helpers(self):

        '''Register the most_popular_groups() function above as a template

        helper function.

        '''

        # Template helper function names should begin with the name of the

        # extension they belong to, to avoid clashing with functions from

        # other extensions.

        return {'example_theme_most_popular_groups': most_popular_groups}

修改 layout1.html

修改 ckanext-example_theme/ckanext/example_theme/templates/home/layout1.html 如下：

{% ckan_extends %}

{% block featured_group %}

  {{ h.recently_changed_packages_activity_stream(limit=4) }}

{% endblock %}

{% block featured_organization %}

  {# Show a list of the site's most popular groups. #}

  <h3>Most popular groups</h3>

  <ul>

    {% for group in h.example_theme_most_popular_groups() %}

      <li>{{ group.display_name }}</li>

    {% endfor %}

  </ul>

{% endblock %}

測試

重新安裝 plugin

切換到 ckanext-example_theme 目錄，執行：

cd ckanext-example_theme

python setup.py develop

重啟 CKAN

• 進入Python Virtual Environment:
  . /usr/lib/ckan/default/bin/activate
• 重啟 CKAN 服務:
  (production版) sudo supervisorctl restart ckan-uwsgi:*
  (develop版) ckan -c /etc/ckan/default/ckan.ini run

結果如下：