Advanced Blueprint Tips

Iterator Stages

This training only focused on one stage, but iterators have three stages! Learn more about this at https://5.docs.plone.org/external/collective.transmogrifier/docs/source/transmogrifier.html#iterators-have-3-stages

Migrating Users & Groups

Jsonify will not export user and group information. These will need to be exported separately. See Users & Groups Migration for example code.

Updating Rich Text

When updating your sites, you may have add-ons that will change in the process. This can adjust text that appears in the body text of pages. Check out PyQuery to help parse the HTML for you. Here's an example that updates oembed tags to uwosh.snippets style:

def new_snippet(self, itemuid):
     return '<span class="snippet-tag snippet-tag-html_snippet" \
         contenteditable="false" data-type="snippet_tag" \
         data-snippet-id="{0}" data-header="">\
         Snippet:[ID={0}]</span>'.format(itemuid)

 def __iter__(self):
     for item in self.previous:
         if 'text' not in item:
             yield item
             continue
         if 'oembed oembed-responsive' not in item['text']:
             yield item
             continue
         txt = PyQuery(item['text'])
         full_text = txt.html()
         for snippet in txt(".oembed"):
             link = PyQuery(snippet)
             href = link("a").attr("href")
             if not href:
                 continue
             if 'resolveuid' in href:
                 linkuid = href.replace('resolveuid/', '')
                 if not api.content.get(UID=linkuid):
                     # leave link as is if we can't find the new one
                     continue
                 # replace link with new snippet
                 full_text = full_text.replace(PyQuery(snippet).outer_html(), self.new_snippet(linkuid))
             else:
                 html_snippets = api.content.find(path='/Plone/' + href)
                 if not html_snippets:
                     continue
                 new = self.new_snippet(html_snippets[0].UID)
                 full_text = full_text.replace(PyQuery(snippet).outer_html(), new)
         item['text'] = full_text

Taking parameters in custom blueprints

See how the PartialCommit blueprint does this.

In the pipeline, we have:

[savepoint]
blueprint = collective.jsonmigrator.partialcommit
every = 1000

Here is the blueprint. options contains any extra parameters that have been passed in. If every is not in the options, 100 is used as the default.

@provider(ISectionBlueprint)
@implementer(ISection)
class PartialCommit(object):


    def __init__(self, transmogrifier, name, options, previous):
        self.previous = previous
        self.step = int(options.get('every', 100))

    def __iter__(self):
        count = 1
        for item in self.previous:
            yield item
            if count % self.step == 0:
                transaction.commit()
                logging.info('Committed after %s' % count)
            count += 1