Retrieve data from database for different wagtail app - wagtail

Question

I'm trying to create a Streamfield block that basically displays all of the posts (diagnoses) from a standard diagnoses listing page so that not only do I have a separate diagnoses page but am also able to add a diagnoses/posts block to other pages?
I've got this so far but it's not working:
Streams > blocks.py:
class DiagnosesListingBlock(blocks.StructBlock):
title = blocks.CharBlock(
required= True,
defualt="Diagnoses",
help_text = 'Text to display as title of Diagnoses section.'
)
data_items = blocks.IntegerBlock(
max_length=2,
blank=False,
null=False,
default="3",
)
def get_context(self, request, *args, **kwargs):
context = super().get_context(request, *args, **kwargs)
context['diagnoses'] = diagnoses.DiagnosisPage.objects.live().public()
return context
class Meta:
template = "streams/disgnoses_listing_block.html"
icon = "edit"
label = "Diagnoses Listing Block"
help_text = "Centered text to display on a page"
Diagnoses > model.py:
class DiagnosisPage(Page):
template = "diagnoses/diagnosis_page.html"
diagnosis_name = models.TextField(
blank=True,
max_length=100,
)
subtitle = models.TextField(
blank=True,
max_length=500,
)
diagnosis_intro = models.TextField(
blank=True,
max_length=500
)
image = models.ForeignKey(
'wagtailimages.Image',
blank=False,
null=True,
on_delete=models.SET_NULL,
help_text='This image will be used on the service listing page and will be cropped to 570px by 370px.',
related_name='+',
)
summary = models.CharField(
max_length=160,
blank=False,
null=False,
default='Curabitur pulvinar euismod ante, ac sagittis ante posuere ac. Vivamus luctus commodo dolor porta feugiat. Fusce at velit id ligula pharetra laoreet.',
help_text='Provides an excert for the blog listing page that gives an intro to what the article is about.',
)
body = StreamField([
("hero_block", blocks.HeroBlock()),
("breadcrumb_block", blocks.BreadcrumbsBlock()),
("highlighted_text_block", blocks.HighlightedTextBlock()),
("title", blocks.TitleAndTextBlock()),
("about_us", blocks.AboutBlock()),
("cards", blocks.CardsBlock()),
("icon_boxes_one", blocks.TextBoxesOneBlock()),
("links", blocks.SiteLinksBlock()),
("image_and_text", blocks.ImageAndTextBlock()),
("image_right_and_text", blocks.ImageRightAndTextBlock()),
("team_members", blocks.TeamMembersBlock()),
("cta_1", blocks.CallToActionOneBlock()),
("cta_2", blocks.CallToActionTwoBlock()),
("cta_3", blocks.CallToActionThreeBlock()),
("large_modal_block", blocks.LargeModalBlock()),
("counters_block", blocks.CountersBlock()),
("share_this_post", blocks.ShareThisPostBlock()),
("blockquotes", blocks.BlockquoteBlock()),
("accordions", blocks.AccordionBlock()),
("testimonial", SnippetChooserBlock(
target_model='testimonials.Testimonial')),
("our_numbers", blocks.OurNumbersBlock()),
("progress_bars", blocks.ProgresssBarsBlock()),
("testimonial", SnippetChooserBlock(
target_model='testimonials.Testimonial',
template='streams/testimonial_block.html'
)),
("pricing_table", blocks.PricingTableBlock(
table_options=new_table_options)),
("logo_block", blocks.LogoBlock()),
("timeline_block", blocks.TimelineBlock()),
("richtext", blocks.RichTextWithTitleBlock()),
], blank=True, null=True)
content_panels = Page.content_panels + [
FieldPanel('diagnosis_name'),
FieldPanel('subtitle'),
FieldPanel('diagnosis_intro'),
ImageChooserPanel('image'),
StreamFieldPanel("body"),
]
diagnosis_listing_block.html:
{% load wagtailcore_tags wagtailimages_tags %}
<section class="p-t-100 p-b-100">
<div class="container">
<div class="row" style="display: table;width: 100%;">
<div class="col-lg-12">{{ self }}
<!--Post Carousel -->
<h4 class="mb-4">{{ self.title }}</h4>
<div class="carousel" data-items="{{ self.data_items }}">
{% for diagnosis in self.diagnoses %}
<!-- Post item-->
<div class="post-item border" style="display: table-cell;">
<div class="post-item-wrap">
<div class="post-image">
<a href="{{ diagnosis.url }}">
{% image diagnosis.image fill-250x150 format-webp as diagnosis_img %}
<img alt="{{ diagnosis.diagnosis_name }} | Dual Diagnosis Network Blog" src="{{ diagnosis_img.url }}"></a>
<!--<span class="post-meta-category"></span>-->
</div>
<div class="post-item-description">
<span class="post-meta-date"><i class="fa fa-calendar-o"></i>Jan 21, 2017</span>
<span class="post-meta-comments"><a href="{{ diagnosis.url }}"><i class="fa fa-comments-o"></i>33
Comments</a></span>
<h2>{{ diagnosis.diagnosis_name }}</h2>
<p>{{ diagnosis.summary }}</p>
Read More <i class="icon-chevron-right"></i>
</div>
</div>
</div>
{% endfor %}
<!-- end: Post item-->
</div>
<!--end: Post Carousel -->
</div>
</div>
</div>
</section>

Answer 1

{% for diagnosis in self.diagnoses %} should be {% for diagnosis in diagnoses %}.
The get_context method defines new variables to be available in the template - in this case, the context['diagnoses'] = ... line defines a variable diagnoses, and that's how you refer to it in the template. self.diagnoses would mean an attribute of the block value instead, but that doesn't exist - it only has attributes title and data_items.