Load and initialize pyodide python wasm module

bt5/erp5_notebook/SkinTemplateItem/portal_skins/erp5_notebook/gadget_jsmd_eval.js.js

-/*global window, console, RSVP, document, URL, eval, XMLHttpRequest, marked */
+/*global window, console, RSVP, document, URL, eval, XMLHttpRequest, marked, WebAssembly */
 /*jslint nomen: true, indent: 2, maxerr: 3 */
 (function (window) {
   "use strict";
@@ -11,6 +11,8 @@
       this._line_list = line_list;
       this._option = option;
     },
+    is_pyodide_loaded = false,
+    pyodide_instance,
     split_line_regex = /[\r\n|\n|\r]/,
     cell_type_regexp = /^\%\% (\w+)/;
 
@@ -68,7 +70,6 @@
     var line_list = jsmd.split(split_line_regex),
       i,
       len = line_list.length,
-      code_type,
       current_line,
       current_type,
       current_header,
@@ -264,13 +265,84 @@
     });
   }
 
+  function loadPyodide(imports, success_callback) {
+    return new RSVP.Queue()
+      .push(function () {
+        return ajax({
+          url: "pyodide.asm.wasm",
+          dataType: "arraybuffer"
+        });
+      })
+      .push(function (evt) {
+        // Compile and instantiate WebAssembly code.
+        // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/instantiate
+        return WebAssembly.instantiate(evt.target.response, imports);
+      })
+      .push(function (result) {
+        // This function act as instantiateWasm
+        // And in instantiateWasm, we have to call the second parameter
+        // See https://emscripten.org/docs/api_reference/module.html#Module.instantiateWasm
+        return success_callback(result.instance);
+      });
+  }
+
+  function checkABI(ABI_number) {
+    // This was needed by pyodide wasm module
+    if (ABI_number !== 1) {
+      throw new Error("Expect ABI number 1, got " + ABI_number);
+    }
+    return true;
+  }
+
+  function initPyodide() {
+    var Module = {};
+
+    // perform the WebAssembly instantiation action
+    // See https://emscripten.org/docs/api_reference/module.html#Module.instantiateWasm
+    Module.instantiateWasm = loadPyodide;
+    Module.checkABI = checkABI;
+    window.Module = Module;
+
+    return RSVP.Queue()
+      .push(function () {
+        return loadJSResource('pyodide.asm.data.js');
+      })
+      .push(function () {
+        return loadJSResource('pyodide.asm.js');
+      })
+      .push(function () {
+        // pyodide is a function defined in pyodide.asm.js
+        // which set the functions under Module
+        pyodide_instance = window.pyodide(Module);
+        var defer = RSVP.defer();
+        // define postRun to resolve the promise
+        // When pyodide loading completed, it will call Module.postRun
+        // to signal the module loaded and ready for next step
+        // https://github.com/emscripten-core/emscripten/blob/1.38.10/src/preamble.js#L1602
+        // https://emscripten.org/docs/api_reference/preamble.js.html
+        Module.postRun = defer.resolve;
+        return defer.promise;
+      });
+  }
+
+  function executePyCell(line_list) {
+    var result, code_text = line_list.join('\n');
+    result = pyodide_instance.runPython(code_text);
+  }
+
   function executeCodeCell(line_list, option) {
-    if (option.language === 'py') {
-      console.log(line_list);
-      console.log("We are processing Python code!!!");
-    } else {
+    if (option.language !== 'py') {
       throw new Error('Unsupported code language: ' + option.language);
     }
+
+    if (!is_pyodide_loaded) {
+      is_pyodide_loaded = true;
+      return initPyodide()
+        .push(function () {
+          return executePyCell(line_list);
+        });
+    }
+    return executePyCell(line_list);
   }
 
   function executeCell(cell) {