move display.py to a stdlib folder

pyscript.core/src/stdlib/display.py

@@ -0,0 +1,141 @@
+# ⚠️ WARNING - both `document` and `window` are added at runtime
+
+import base64
+import html
+import io
+import re
+
+_MIME_METHODS = {
+    "__repr__": "text/plain",
+    "_repr_html_": "text/html",
+    "_repr_markdown_": "text/markdown",
+    "_repr_svg_": "image/svg+xml",
+    "_repr_png_": "image/png",
+    "_repr_pdf_": "application/pdf",
+    "_repr_jpeg_": "image/jpeg",
+    "_repr_latex": "text/latex",
+    "_repr_json_": "application/json",
+    "_repr_javascript_": "application/javascript",
+    "savefig": "image/png",
+}
+
+
+def _render_image(mime, value, meta):
+    # If the image value is using bytes we should convert it to base64
+    # otherwise it will return raw bytes and the browser will not be able to
+    # render it.
+    if isinstance(value, bytes):
+        value = base64.b64encode(value).decode("utf-8")
+
+    # This is the pattern of base64 strings
+    base64_pattern = re.compile(
+        r"^([A-Za-z0-9+/]{4})*([A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{2}==)?$"
+    )
+    # If value doesn't match the base64 pattern we should encode it to base64
+    if len(value) > 0 and not base64_pattern.match(value):
+        value = base64.b64encode(value.encode("utf-8")).decode("utf-8")
+
+    data = f"data:{mime};charset=utf-8;base64,{value}"
+    attrs = " ".join(['{k}="{v}"' for k, v in meta.items()])
+    return f'<img src="{data}" {attrs}></img>'
+
+
+def _identity(value, meta):
+    return value
+
+
+_MIME_RENDERERS = {
+    "text/plain": html.escape,
+    "text/html": _identity,
+    "image/png": lambda value, meta: _render_image("image/png", value, meta),
+    "image/jpeg": lambda value, meta: _render_image("image/jpeg", value, meta),
+    "image/svg+xml": _identity,
+    "application/json": _identity,
+    "application/javascript": lambda value, meta: f"<script>{value}<\\/script>",
+}
+
+
+def _eval_formatter(obj, print_method):
+    """
+    Evaluates a formatter method.
+    """
+    if print_method == "__repr__":
+        return repr(obj)
+    elif hasattr(obj, print_method):
+        if print_method == "savefig":
+            buf = io.BytesIO()
+            obj.savefig(buf, format="png")
+            buf.seek(0)
+            return base64.b64encode(buf.read()).decode("utf-8")
+        return getattr(obj, print_method)()
+    elif print_method == "_repr_mimebundle_":
+        return {}, {}
+    return None
+
+
+def _format_mime(obj):
+    """
+    Formats object using _repr_x_ methods.
+    """
+    if isinstance(obj, str):
+        return html.escape(obj), "text/plain"
+
+    mimebundle = _eval_formatter(obj, "_repr_mimebundle_")
+    if isinstance(mimebundle, tuple):
+        format_dict, _ = mimebundle
+    else:
+        format_dict = mimebundle
+
+    output, not_available = None, []
+    for method, mime_type in reversed(_MIME_METHODS.items()):
+        if mime_type in format_dict:
+            output = format_dict[mime_type]
+        else:
+            output = _eval_formatter(obj, method)
+
+        if output is None:
+            continue
+        elif mime_type not in _MIME_RENDERERS:
+            not_available.append(mime_type)
+            continue
+        break
+    if output is None:
+        if not_available:
+            window.console.warn(  # noqa: F821
+                f"Rendered object requested unavailable MIME renderers: {not_available}"
+            )
+        output = repr(output)
+        mime_type = "text/plain"
+    elif isinstance(output, tuple):
+        output, meta = output
+    else:
+        meta = {}
+    return _MIME_RENDERERS[mime_type](output, meta), mime_type
+
+
+def _write(element, value, append=False):
+    html, mime_type = _format_mime(value)
+    if html == "\\n":
+        return
+
+    if append:
+        out_element = document.createElement("div")  # noqa: F821
+        element.append(out_element)
+    else:
+        out_element = element.lastElementChild
+        if out_element is None:
+            out_element = element
+
+    if mime_type in ("application/javascript", "text/html"):
+        script_element = document.createRange().createContextualFragment(  # noqa: F821
+            html
+        )  # noqa: F821
+        out_element.append(script_element)
+    else:
+        out_element.innerHTML = html
+
+
+def display(*values, target=None, append=True):
+    element = document.getElementById(target)  # noqa: F821
+    for v in values:
+        _write(element, v, append=append)