Initial commit

env/lib/python3.10/site-packages/draftjs_exporter/engines/string.py

@@ -0,0 +1,122 @@
+from html import escape
+from typing import List, Optional, Sequence, Union
+
+from draftjs_exporter.engines.base import Attr, DOMEngine
+from draftjs_exporter.types import HTML, Tag
+
+# http://w3c.github.io/html/single-page.html#void-elements
+# https://github.com/html5lib/html5lib-python/blob/0cae52b2073e3f2220db93a7650901f2200f2a13/html5lib/constants.py#L560
+VOID_ELEMENTS = (
+    "area",
+    "base",
+    "br",
+    "col",
+    "embed",
+    "hr",
+    "img",
+    "input",
+    "link",
+    "meta",
+    "param",
+    "source",
+    "track",
+    "wbr",
+)
+
+
+class Elt:
+    """
+    A DOM element that the string engine manipulates.
+    This class doesn't do much, but the exporter relies on
+    comparing elements by reference so it's useful nonetheless.
+    """
+
+    __slots__ = ("type", "attr", "children", "markup")
+
+    def __init__(self, type_: Tag, attr: Optional[Attr], markup: HTML = None):
+        self.type = type_
+        self.attr = attr
+        self.children: List["Elt"] = []
+        self.markup = markup
+
+    @staticmethod
+    def from_html(markup: HTML) -> "Elt":
+        return Elt("escaped_html", None, markup)
+
+
+class DOMString(DOMEngine):
+    """
+    String concatenation implementation of the DOM API.
+    """
+
+    @staticmethod
+    def create_tag(type_: Tag, attr: Optional[Attr] = None) -> Elt:
+        return Elt(type_, attr)
+
+    @staticmethod
+    def parse_html(markup: HTML) -> Elt:
+        """
+        Allows inserting arbitrary HTML into the exporter output.
+        Treats the HTML as if it had been escaped and was safe already.
+        """
+        return Elt.from_html(markup)
+
+    @staticmethod
+    def append_child(elt: Elt, child: Elt) -> None:
+        # This check is necessary because the current wrapper_state implementation
+        # has an issue where it inserts elements multiple times.
+        # This must be skipped for text, which can be duplicated.
+        is_existing_ref = child in elt.children and isinstance(child, Elt)
+        if not is_existing_ref:
+            elt.children.append(child)
+
+    @staticmethod
+    def render_attrs(attr: Attr) -> str:
+        attrs = [f' {k}="{escape(v)}"' for k, v in attr.items()]
+        return "".join(attrs)
+
+    @staticmethod
+    def render_children(children: Sequence[Union[HTML, Elt]]) -> HTML:
+        return "".join(
+            [
+                DOMString.render(c)
+                if isinstance(c, Elt)
+                else escape(c, quote=False)
+                for c in children
+            ]
+        )
+
+    @staticmethod
+    def render(elt: Elt) -> HTML:
+        type_ = elt.type
+        attr = DOMString.render_attrs(elt.attr) if elt.attr else ""
+        children = (
+            DOMString.render_children(elt.children) if elt.children else ""
+        )
+
+        if type_ == "fragment":
+            return children
+
+        if type_ in VOID_ELEMENTS:
+            return f"<{type_}{attr}/>"
+
+        if type_ == "escaped_html":
+            return elt.markup  # type: ignore
+
+        return f"<{type_}{attr}>{children}</{type_}>"
+
+    @staticmethod
+    def render_debug(elt: Elt) -> HTML:
+        type_ = elt.type
+        attr = DOMString.render_attrs(elt.attr) if elt.attr else ""
+        children = (
+            DOMString.render_children(elt.children) if elt.children else ""
+        )
+
+        if type_ in VOID_ELEMENTS:
+            return f"<{type_}{attr}/>"
+
+        if type_ == "escaped_html":
+            return elt.markup  # type: ignore
+
+        return f"<{type_}{attr}>{children}</{type_}>"