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I have a CMS based on wagtail, and have recently re-written it in a more sensible fashion. I have written a script to migrate the old content to this new version, which is based on wagtail 2.3 (old version was on wagtail 1.11). I have written the migration script (to re-construct various foreign keys etc) and all content has been populated and seems to be working except for the render of StreamFields.

Frustratingly, when I switch back to my test db for v2, this works fine (content is rendered) - I've been scouring my databases for differences between the two rows (in wagtailcore_page or blog_blogpostpage) and can't see any difference. There's obviously something I'm missing in the way wagtail fetches StreamField content, can anyone enlighten me as to what I might have missed in the migration? Many thanks!!

models.py

class BlogPostPage(Page):  # Individual blog post
    template = 'blog/post_page.html'
    parent_page_types = ['blog.BlogIndexPage']
    show_in_menus_default = True
    author = models.ForeignKey(
        User, on_delete=models.PROTECT, default=1,
    )
    description = models.CharField(
        max_length=300, blank=False,
        help_text="Add a brief (max 300 characters) description for this blog post."
    )

    date = models.DateField(
        "Post date",
        help_text="This date may be displayed on the blog post. "
                  "It is not used to schedule posts to go live at a later date."
    )
    body = StreamField([
        ('heading', blocks.CharBlock(classname="full title")),
        ('paragraph', blocks.RichTextBlock()),
        ('embed', EmbedBlock()),
        ('image', ImageChooserBlock(classname='img-responsive')),
        ('code', CodeBlock(label='Code')),
        ('table', TableBlock(label='Table'))
    ], help_text="Create content by adding new blocks.")

table blog_blogpostpage entry:

"page_ptr_id","description","date","body","author_id"
23,"Now including Blog!","2018-12-06","[{""type"": ""paragraph"", ""value"": ""<p>Since the first release we&#x27;ve made some improvements and upgrades...</p>"", ""id"": ""25fe32be-2090-42dd-8e3e-4df53c494227""}]",15

migration_script.sh

INSERT INTO "public"."wagtailcore_page"("path","depth","numchild","title","slug","live","has_unpublished_changes","url_path","seo_title","show_in_menus","search_description","go_live_at","expire_at","expired","content_type_id","owner_id","locked","latest_revision_created_at","first_published_at","live_revision_id","last_published_at","draft_title")
        VALUES
        (E'00010002000O0001',4,0,E'Release: version 2',E'release-version-2',TRUE,FALSE,E'/home/blog/release-version-2/',E'',TRUE,E'',NULL,NULL,FALSE,6,15,FALSE,E'2018-12-06 16:58:10.897348+08',E'2018-12-06 16:58:10.926032+08',NULL,E'2018-12-06 16:58:10.926032+08',E'Release: version 2');

    INSERT INTO "public"."blog_blogpostpage"("page_ptr_id","description","date","body","author_id")
        VALUES
        ((SELECT id FROM wagtailcore_page WHERE path='00010002000O0001'),E'Now including Blog!',E'2018-12-06',E'[{"type": "paragraph", "value": "<p>Since the first release we&#x27;ve made some improvements and upgrades...</p>", "id": "25fe32be-2090-42dd-8e3e-4df53c494227"}]',15);

template.html

{% include_block page.body %}

^^^ Nothing is shown for the page.body field, but description, date and author are rendered.

Liz
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  • What happens when you open up the shell and inspect the field? Eg: `python manage.py shell`, `from wagtail.core.models import Page`, `Page.objects.get(pk=some_id).specific.body.stream_data` it should show a list of dicts. – allcaps Dec 06 '18 at 21:31
  • >>> Page.objects.get(pk=127).specific.description 'Now including Blog!' >>> Page.objects.get(pk=127).specific.body [] >>> Page.objects.get(pk=127).specific.body.stream_data [] – Liz Dec 07 '18 at 06:10
  • An empty list! The db column body for blog_blogpostpage contains content... [{""type"": ""paragraph"", ""value"": ""

    Since the first release we've made some improvements and upgrades...

    "", ""id"": ""25fe32be-2090-42dd-8e3e-4df53c494227""}]     – Liz Dec 07 '18 at 06:12
  • Clearly I'm missing some fundamental relationship between user-defined Page models and wagtailcore_page... or something else altogether :( – Liz Dec 07 '18 at 06:13
  • This is how Multi-table inheritance works. https://docs.djangoproject.com/en/2.1/topics/db/models/#multi-table-inheritance. – allcaps Dec 07 '18 at 09:00
  • That is not the issue. My streamfields look like valid json. Yours have double quotes. `[{""type"": ""paragraph"", ` should be `[{"type": "paragraph", ` – allcaps Dec 07 '18 at 09:01
  • Good grief. That's the issue... those double quotes. Thank you so much @allcaps, I had been staring at this for hours and just didn't see it! – Liz Dec 07 '18 at 12:04
  • I posted my comment as answer. – allcaps Dec 09 '18 at 12:42

1 Answers1

2

Your data migration created invalid JSON:

[{""type"": ""paragraph"", ""value"": ""<p>S ...

Should have single quotes:

[{"type": "paragraph", "value": "<p>S ...
allcaps
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