Introducing Google App Engine Paginator

Table of contents

Summary

Need a way to paginate through a GQL query easily? gae_paginator handles the generation of next/previous page URLs, paginates on both unique and non-unique properties, and wants to be as efficient and easy to use as possible.

Getting Started

  1. Download the source and copy the gae_paginator/ folder anywhere inside your App Engine project directory.

  2. That's it! Use it like so, in your handlers:

    import os
    
    from google.appengine.ext.webapp import template
    import webapp2
    
    from gae_paginator import Paginator
    
    class YourHandler(webapp2.RequestHandler):
    
      def get(self):
      paginator = Paginator(YourModel, 'some_column = :1 AND other_column = :2',
                            ['some_value', 'other_value'], expect_duplicates=True,
                            per_page=50, paginate_on='-created')
      page = paginator.get_page(request=self.request)
      path = os.path.join(os.path.dirname(__file__), 'index.html')
      self.response.out.write(template.render(path, {
        'objects': list(page),
        'page': page,
      })
    
  3. In your django template:

    {% if page.has_previous %}
        <a href="{{ page.get_previous_url }}">&laquo; Previous page</a>
    {% endif %}
    {% if page.has_next %}
        <a href="{{ page.get_next_url }}">Next page &raquo;</a>
    {% endif %}
    

    Or jinja2 template:

    {% if page.has_previous() %}
         <a href="{{ page.get_previous_url() }}">&laquo; Previous page</a>
    {% endif %}
    {% if page.has_next() %}
        <a href="{{ page.get_next_url() }}">Next page &raquo;</a>
    {% endif %}
    

Features

  • Simple pagination by key
  • Paginate by non-unique properties with a specified tolerance for duplicates.

  • Example: paginate songs by artist name, 10 songs per page, expect 100 duplicates. Set: expect_duplicates=100

  • Order and paginate by a custom column (Date/DateTime and key supported and tested).
  • Show next and previous buttons only when there is actual data before/after.
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