Initial commit

env/lib/python3.10/site-packages/wagtail/embeds/blocks.py

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+from django.core.exceptions import ValidationError
+from django.utils.functional import cached_property
+from django.utils.translation import gettext_lazy as _
+
+from wagtail import blocks
+from wagtail.embeds.format import embed_to_frontend_html
+
+
+class EmbedValue:
+    """
+    Native value of an EmbedBlock. Should, at minimum, have a 'url' property
+    and render as the embed HTML when rendered in a template.
+    NB We don't use a wagtailembeds.model.Embed object for this, because
+    we want to be able to do {% embed value.url 500 %} without
+    doing a redundant fetch of the embed at the default width.
+    """
+
+    def __init__(self, url, max_width=None, max_height=None):
+        self.url = url
+        self.max_width = max_width
+        self.max_height = max_height
+
+    @cached_property
+    def html(self):
+        return embed_to_frontend_html(self.url, self.max_width, self.max_height)
+
+    def __str__(self):
+        return self.html
+
+
+class EmbedBlock(blocks.URLBlock):
+    def get_default(self):
+        # Allow specifying the default for an EmbedBlock as either an EmbedValue or a string (or None).
+        if not self.meta.default:
+            return None
+        elif isinstance(self.meta.default, EmbedValue):
+            return self.meta.default
+        else:
+            # assume default has been passed as a string
+            return EmbedValue(
+                self.meta.default,
+                getattr(self.meta, "max_width", None),
+                getattr(self.meta, "max_height", None),
+            )
+
+    def to_python(self, value):
+        # The JSON representation of an EmbedBlock's value is a URL string;
+        # this should be converted to an EmbedValue (or None).
+        if not value:
+            return None
+        else:
+            return EmbedValue(
+                value,
+                getattr(self.meta, "max_width", None),
+                getattr(self.meta, "max_height", None),
+            )
+
+    def get_prep_value(self, value):
+        # serialisable value should be a URL string
+        if value is None:
+            return ""
+        else:
+            return value.url
+
+    def value_for_form(self, value):
+        # the value to be handled by the URLField is a plain URL string (or the empty string)
+        if value is None:
+            return ""
+        else:
+            return value.url
+
+    def value_from_form(self, value):
+        # convert the value returned from the form (a URL string) to an EmbedValue (or None)
+        if not value:
+            return None
+        else:
+            return EmbedValue(
+                value,
+                getattr(self.meta, "max_width", None),
+                getattr(self.meta, "max_height", None),
+            )
+
+    def clean(self, value):
+        if isinstance(value, EmbedValue) and not value.html:
+            raise ValidationError(_("Cannot find an embed for this URL."))
+        return super().clean(value)
+
+    def normalize(self, value):
+        if isinstance(value, EmbedValue):
+            return value
+        return EmbedValue(value)
+
+    class Meta:
+        icon = "media"