[next] Bring in the good old PyScript display (#1628)

pyscript.core/package-lock.json

@@ -1,12 +1,12 @@
 {
     "name": "@pyscript/core",
-    "version": "0.1.1",
+    "version": "0.1.2",
     "lockfileVersion": 3,
     "requires": true,
     "packages": {
         "": {
             "name": "@pyscript/core",
-            "version": "0.1.1",
+            "version": "0.1.2",
             "license": "APACHE-2.0",
             "dependencies": {
                 "@ungap/with-resolvers": "^0.1.0",
@@ -18,6 +18,7 @@
                 "@rollup/plugin-terser": "^0.4.3",
                 "rollup": "^3.27.2",
                 "rollup-plugin-postcss": "^4.0.2",
+                "rollup-plugin-string": "^3.0.0",
                 "static-handler": "^0.4.2",
                 "typescript": "^5.1.6"
             }
@@ -1591,6 +1592,15 @@
                 "postcss": "8.x"
             }
         },
+        "node_modules/rollup-plugin-string": {
+            "version": "3.0.0",
+            "resolved": "https://registry.npmjs.org/rollup-plugin-string/-/rollup-plugin-string-3.0.0.tgz",
+            "integrity": "sha512-vqyzgn9QefAgeKi+Y4A7jETeIAU1zQmS6VotH6bzm/zmUQEnYkpIGRaOBPY41oiWYV4JyBoGAaBjYMYuv+6wVw==",
+            "dev": true,
+            "dependencies": {
+                "rollup-pluginutils": "^2.4.1"
+            }
+        },
         "node_modules/rollup-pluginutils": {
             "version": "2.8.2",
             "resolved": "https://registry.npmjs.org/rollup-pluginutils/-/rollup-pluginutils-2.8.2.tgz",

pyscript.core/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@pyscript/core",
-    "version": "0.1.1",
+    "version": "0.1.2",
     "type": "module",
     "description": "PyScript",
     "main": "core.js",
@@ -39,6 +39,7 @@
         "@rollup/plugin-terser": "^0.4.3",
         "rollup": "^3.27.2",
         "rollup-plugin-postcss": "^4.0.2",
+        "rollup-plugin-string": "^3.0.0",
         "static-handler": "^0.4.2",
         "typescript": "^5.1.6"
     },

pyscript.core/rollup/core.config.js

@@ -3,10 +3,20 @@
 
 import { nodeResolve } from "@rollup/plugin-node-resolve";
 import terser from "@rollup/plugin-terser";
+import { string } from "rollup-plugin-string";
+
+const plugins = [
+    string({
+        // Required to be specified
+        include: "**/*.py",
+    }),
+];
 
 export default {
     input: "./src/core.js",
-    plugins: process.env.NO_MIN ? [nodeResolve()] : [nodeResolve(), terser()],
+    plugins: plugins.concat(
+        process.env.NO_MIN ? [nodeResolve()] : [nodeResolve(), terser()],
+    ),
     output: {
         esModule: true,
         file: "./core.js",

pyscript.core/src/core.js

@@ -2,6 +2,9 @@ import "@ungap/with-resolvers";
 import { $ } from "basic-devtools";
 import { define, XWorker } from "polyscript";
 
+// this is imported as string (via rollup)
+import display from "./display.py";
+
 // TODO: this is not strictly polyscript related but handy ... not sure
 //       we should factor this utility out a part but this works anyway.
 import { queryTarget } from "../node_modules/polyscript/esm/script-handler.js";
@@ -79,6 +82,17 @@ const registerModule = ({ XWorker: $XWorker, interpreter, io }) => {
         worker.onerror = ({ error }) => io.stderr(error);
         return worker;
     }
+    // trap once the python `display` utility (borrowed from "classic PyScript")
+    // provide the regular Pyodide globals instead of those from xworker
+    const pyDisplay = interpreter.runPython(
+        [
+            "import js",
+            "document=js.document",
+            "window=js",
+            display,
+            "display",
+        ].join("\n"),
+    );
     interpreter.registerJsModule("pyscript", {
         PyWorker,
         document,
@@ -91,11 +105,8 @@ const registerModule = ({ XWorker: $XWorker, interpreter, io }) => {
                 ? currentElement.target.id
                 : currentElement.id;
 
-            // TODO: decide which feature of display we want to keep
             return (what, target = id, append = true) => {
-                const element = document.getElementById(target);
-                if (append) element.append(what);
-                else element.textContent = what;
+                pyDisplay.callKwargs(...[].concat(what), { target, append });
             };
         },
     });
@@ -125,13 +136,16 @@ export const hooks = {
 
 const workerPyScriptModule = [
     "from pyodide_js import FS",
-    `FS.writeFile('./pyscript.py', '${[
-        "import polyscript",
-        "document=polyscript.xworker.window.document",
-        "window=polyscript.xworker.window",
-        "sync=polyscript.xworker.sync",
-    ].join(";")}')`,
-].join(";");
+    `FS.writeFile('./pyscript.py', ${JSON.stringify(
+        [
+            "import polyscript",
+            "document=polyscript.xworker.window.document",
+            "window=polyscript.xworker.window",
+            "sync=polyscript.xworker.sync",
+            display,
+        ].join("\n"),
+    )})`,
+].join("\n");
 
 const workerHooks = {
     codeBeforeRunWorker: () =>

pyscript.core/src/display.py

@@ -0,0 +1,142 @@
+# ⚠️ 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(
+                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):
+    global _pyscript_id
+
+    html, mime_type = _format_mime(value)
+    if html == "\\n":
+        return
+
+    if append:
+        out_element = document.createElement("div")
+        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(html)
+        out_element.append(script_element)
+    else:
+        out_element.innerHTML = html
+
+
+def display(*values, target=None, append=True):
+    element = document.getElementById(target)
+    for v in values:
+        _write(element, v, append=append)

pyscript.core/test/index.html

@@ -8,6 +8,9 @@
         <script type="module" src="../core.js"></script>
     </head>
     <body>
-        <py-script>display("Hello PyScript Next")</py-script>
+        <script type="py">
+            from pyscript import display
+            display("Hello PyScript Next")
+        </script>
     </body>
 </html>

pyscript.core/test/worker.html

@@ -6,10 +6,6 @@
         <title>PyScript Next</title>
         <link rel="stylesheet" href="../core.css" />
 
-        <!-- the worker attribute -->
-        <script type="module" src="../core.js"></script>
-        <script type="py" worker="./worker.py" config="./config.json"></script>
-
         <!-- the PyWorker approach -->
         <script type="module">
           import { PyWorker } from '../core.js';
@@ -17,8 +13,12 @@
           // the type is overwritten as "pyodide" in PyScript as the module
           // lives in that env too
         </script>
+
+        <!-- the worker attribute -->
+        <script type="py" worker="./worker.py" config="./config.json"></script>
+
+        <!-- this is only to test the non-blocking behavior -->
         <script>
-          // this is only to test non-blocking nature/bootstrap
           addEventListener('DOMContentLoaded', () => {
             const div = document.body.appendChild(
               document.createElement('div')
@@ -31,4 +31,7 @@
           });
         </script>
     </head>
+    <body>
+      <div id="test"></div>
+    </body>
 </html>

pyscript.core/test/worker.py

@@ -1,5 +1,5 @@
-from pyscript import document
+from pyscript import display
 
 import a
 
-document.body.append("Hello World")
+display("Hello World", target="test", append=True)