refacture image_srcset method to be reusable in plone.namedfile

plone/outputfilters/filters/image_srcset.py

@@ -2,32 +2,17 @@
 import re
 
 from bs4 import BeautifulSoup
-from plone.base.interfaces import IImagingSchema
 from plone.outputfilters.interfaces import IFilter
-from plone.registry.interfaces import IRegistry
 from Products.CMFPlone.utils import safe_nativestring
-from zope.component import getUtility
 from zope.interface import implementer
+from plone.outputfilters.utils import Img2PictureTag
 
 logger = logging.getLogger("plone.outputfilter.image_srcset")
 
 
 @implementer(IFilter)
 class ImageSrcsetFilter(object):
-    """Converts img/figure tags with a data-srcset attribute into srcset definition.
-    <picture>
-        <source media="(max-width:768px) and (orientation:portrait)"
-                srcset="resolveuid/44d84ffd32924bb8b9dbd720f43e761c/@@images/image/teaser" />
-        <source media="(max-width:768px)"
-                srcset="resolveuid/44d84ffd32924bb8b9dbd720f43e761c/@@images/image/large" />
-        <source media="(min-width:992px)"
-                srcset="resolveuid/44d84ffd32924bb8b9dbd720f43e761c/@@images/image/larger" />
-        <source media="(min-width:1200px)"
-                srcset="resolveuid/44d84ffd32924bb8b9dbd720f43e761c/@@images/image/great" />
-        <source media="(min-width:1400px)"
-                srcset="resolveuid/44d84ffd32924bb8b9dbd720f43e761c/@@images/image/huge" />
-        <img src="resolveuid/44d84ffd32924bb8b9dbd720f43e761c/@@images/image/huge" />
-    </picture>
+    """Converts img tags with a data-srcset attribute into picture tag with srcset definition.
     """
 
     order = 700
@@ -49,36 +34,8 @@ def __init__(self, context=None, request=None):
         self.current_status = None
         self.context = context
         self.request = request
+        self.img2picturetag = Img2PictureTag()
 
-    @property
-    def allowed_scales(self):
-        registry = getUtility(IRegistry)
-        settings = registry.forInterface(IImagingSchema, prefix="plone", check=False)
-        return settings.allowed_sizes
-
-    @property
-    def image_srcsets(self):
-        registry = getUtility(IRegistry)
-        settings = registry.forInterface(IImagingSchema, prefix="plone", check=False)
-        return settings.image_srcsets
-
-    def get_scale_name(self, scale_line):
-        parts = scale_line.split(" ")
-        return parts and parts[0] or ""
-
-    def get_scale_width(self, scale):
-        """ get width from allowed_scales line
-            large 800:65536
-        """
-        for s in self.allowed_scales:
-            parts = s.split(" ")
-            if not parts:
-                continue
-            if parts[0] == scale:
-                dimentions = parts[1].split(":")
-                if not dimentions:
-                    continue
-                return dimentions[0]
 
     def __call__(self, data):
         data = re.sub(r"<([^<>\s]+?)\s*/>", self._shorttag_replace, data)
@@ -88,59 +45,16 @@ def __call__(self, data):
             srcset_name = elem.attrs.get("data-srcset", "")
             if not srcset_name:
                 continue
-            elem.replace_with(self.convert_to_srcset(srcset_name, elem, soup))
-        return str(soup)
-
-    def convert_to_srcset(self, srcset_name, elem, soup):
-        """Converts the element to a srcset definition"""
-        srcset_config = self.image_srcsets.get(srcset_name)
-        if not srcset_config:
-            logger.warn(
-                "Could not find the given srcset_name {0}, leave tag untouched!".format(
-                    srcset_name
+            srcset_config = self.img2picturetag.image_srcsets.get(srcset_name)
+            if not srcset_config:
+                logger.warn(
+                    "Could not find the given srcset_name {0}, leave tag untouched!".format(
+                        srcset_name
+                    )
                 )
-            )
-            return elem
-        allowed_scales = self.allowed_scales
-        sourceset = srcset_config.get("sourceset")
-        if not sourceset:
-            return elem
-        src = elem.attrs.get("src")
-        picture_tag = soup.new_tag("picture")
-        css_classes = elem.attrs.get("class")
-        if "captioned" in css_classes:
-            picture_tag["class"] = "captioned"
-        for i, source in enumerate(sourceset):
-            target_scale = source["scale"]
-            media = source.get("media")
-
-            additional_scales = source.get("additionalScales", None)
-            if additional_scales is None:
-                additional_scales = [self.get_scale_name(s) for s in allowed_scales if s != target_scale]
-            source_scales = [target_scale] + additional_scales
-            source_srcset = []
-            for scale in source_scales:
-                scale_url = self.update_src_scale(src=src, scale=scale)
-                scale_width = self.get_scale_width(scale)
-                source_srcset.append("{0} {1}w".format(scale_url, scale_width))
-            source_tag = soup.new_tag(
-                "source", srcset=",\n".join(source_srcset)
-            )
-            if media:
-                source_tag["media"] = media
-            picture_tag.append(source_tag)
-            if i == len(sourceset) - 1:
-                img_tag = soup.new_tag(
-                    "img", src=self.update_src_scale(src=src, scale=target_scale),
-                )
-                for k, attr in elem.attrs.items():
-                    if k in ["src", "srcset"]:
-                        continue
-                    img_tag.attrs[k] = attr
-                img_tag["loading"] = "lazy"
-                picture_tag.append(img_tag)
-        return picture_tag
-
-    def update_src_scale(self, src, scale):
-        parts = src.split("/")
-        return "/".join(parts[:-1]) + "/{}".format(scale)
+                continue
+            sourceset = srcset_config.get("sourceset")
+            if not sourceset:
+                continue
+            elem.replace_with(self.img2picturetag.create_picture_tag(sourceset, elem.attrs))
+        return str(soup)

plone/outputfilters/utils.py

@@ -0,0 +1,88 @@
+import logging
+
+from plone.base.interfaces import IImagingSchema
+from plone.registry.interfaces import IRegistry
+from zope.component import getUtility
+from bs4 import BeautifulSoup
+
+logger = logging.getLogger("plone.outputfilter.image_srcset")
+
+
+class Img2PictureTag(object):
+    @property
+    def allowed_scales(self):
+        registry = getUtility(IRegistry)
+        settings = registry.forInterface(IImagingSchema, prefix="plone", check=False)
+        return settings.allowed_sizes
+
+    @property
+    def image_srcsets(self):
+        registry = getUtility(IRegistry)
+        settings = registry.forInterface(IImagingSchema, prefix="plone", check=False)
+        return settings.image_srcsets
+
+    def get_scale_name(self, scale_line):
+        parts = scale_line.split(" ")
+        return parts and parts[0] or ""
+
+    def get_scale_width(self, scale):
+        """get width from allowed_scales line
+        large 800:65536
+        """
+        for s in self.allowed_scales:
+            parts = s.split(" ")
+            if not parts:
+                continue
+            if parts[0] == scale:
+                dimentions = parts[1].split(":")
+                if not dimentions:
+                    continue
+                return dimentions[0]
+
+    def create_picture_tag(self, sourceset, attributes):
+        """Converts the element to a srcset definition"""
+        soup = BeautifulSoup("", "html.parser")
+        allowed_scales = self.allowed_scales
+        src = attributes.get("src")
+        picture_tag = soup.new_tag("picture")
+        css_classes = attributes.get("class")
+        if "captioned" in css_classes:
+            picture_tag["class"] = "captioned"
+        for i, source in enumerate(sourceset):
+            target_scale = source["scale"]
+            media = source.get("media")
+
+            additional_scales = source.get("additionalScales", None)
+            if additional_scales is None:
+                additional_scales = [
+                    self.get_scale_name(s) for s in allowed_scales if s != target_scale
+                ]
+            source_scales = [target_scale] + additional_scales
+            source_srcset = []
+            for scale in source_scales:
+                scale_url = self.update_src_scale(src=src, scale=scale)
+                scale_width = self.get_scale_width(scale)
+                source_srcset.append("{0} {1}w".format(scale_url, scale_width))
+            source_tag = soup.new_tag("source", srcset=",\n".join(source_srcset))
+            if media:
+                source_tag["media"] = media
+            picture_tag.append(source_tag)
+            if i == len(sourceset) - 1:
+                img_tag = soup.new_tag(
+                    "img",
+                    src=self.update_src_scale(src=src, scale=target_scale),
+                )
+                for k, attr in attributes.items():
+                    if k in ["src", "srcset"]:
+                        continue
+                    img_tag.attrs[k] = attr
+                img_tag["loading"] = "lazy"
+                picture_tag.append(img_tag)
+        return picture_tag
+
+    def update_src_scale(self, src, scale):
+        parts = src.split("/")
+        if "." in src:
+            field_name = parts[-1].split("-")[0]
+            return "/".join(parts[:-1]) + "/{0}/{1}".format(field_name, scale)
+        return "/".join(parts[:-1]) + "/{}".format(scale)