Andy Chosak chosak

We had a nice open session this afternoon at PyCon US, organized by Sean Harrison from Caktus Group. There were about 15 people in the room. The session agenda was generally to discuss improving Wagtail for developers.

StreamField data migrations

Adding fields or blocks won't cause problems as long as you don't rename or removing anything.

Sean presented a nice multi-step approach that he recommends when migrating StreamFields. This way you can run each step independently and verify that it worked correctly.

First add the new field or block (example).
Make a migration that copies the data from old fields to new fields, but don't remove anything yet (example).

	{# home/templates/home/home_page.html #}
	{# Uses safecache instead of cache to prevent caching of preview content #}
	{% load safecache %}

	{# Usage of cache tag remains the same #}
	{% cache 3600 homepage_charfield %}
	{{ self.a_charfield }}
	{% endcache %}

	#!/usr/bin/env python

	from __future__ import absolute_import, print_function, unicode_literals

	import argparse
	import os
	import re
	import requests

	from getpass import getpass

	<!DOCTYPE html>
	<meta charset="utf-8">
	<title>projects/indy/data/tweets/indy-0.json</title>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.17/d3.min.js"></script>
	<style>

	.axis text {
	font: 10px sans-serif;
	}