[WIP] Allow text to be fetched from a url

app.py

@@ -567,7 +567,12 @@ def parse():
                 exception = ex
 
         try:
-            response['Code'] = transpile_result.code
+            t = textwrap.dedent("""\
+            print(load_url('https://raw.githubusercontent.com/ebertmi/skulpt/epy_build/src/file.js'))
+            """)
+            response['Code'] = t + transpile_result.code
+
+            # response['Code'] = transpile_result.code
             source_map_result = transpile_result.source_map.get_result()
 
             for i, mapping in source_map_result.items():

static/js/app.ts

@@ -12,7 +12,10 @@
 import { incrementDebugLine, initializeDebugger, load_variables, startDebug } from './debugging';
 import { localDelete, localLoad, localSave } from './local';
 import { initializeLoginLinks } from './auth';
+
+import { postJson, fetchText } from './comm';
+
 import { postJson } from './comm';
 import { LocalSaveWarning } from './local-save-warning';
 import { HedyEditor, EditorType } from './editor';
 import { stopDebug } from "./debugging";
@@ -1045,6 +1048,11 @@
         return ((hasSleep) ? 20000 : 5000);
       }) ()
     });
+
+    (Sk as any).builtins.load_url = new Sk.builtin.func((url_text:any) => {
+      const ret = fetchText(url_text);
+      return new Sk.misceval.promiseToSuspension(ret.then(Sk.ffi.remapToPy));
+    });
 
     (Sk as any).builtins.play = new Sk.builtin.func((notes:any) => {
         //const now = Tone.now()
@@ -1083,11 +1091,13 @@
         error.showWarning(ClientMessages['Transpile_warning'], ClientMessages['Empty_output']);
         return;
       }
+
       if (!hasWarnings && code !== last_code) {
           showSuccesMessage(); //FH nov 2023: typo in success :)
           last_code = code;
       }
       if (cb) cb ();
+
     }).catch(function(err) {
       const errorMessage = errorMessageFromSkulptError(err) || null;
       if (!errorMessage) {

static/js/comm.ts

@@ -102,4 +102,25 @@ function ajaxError(err: any) {
     // https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/readyState
     internetError: err.readyState < 4,
   });
-}
+}
+
+/**
+ * Fetch a text file from a URL (hopefully it supports cross-origin calls)
+ */
+export function fetchText(url: string): Promise<string> {
+  // Use the fetch API, if available (TODO)
+//   if (window.fetch !== undefined) {
+//     return postJsonUsingFetch(url, data);
+//   }
+
+  return new Promise((ok, ko) => {
+    $.ajax({
+      type: 'GET',
+      url,
+    }).done((response: any) => {
+      ok(response);
+    }).fail((err) => {
+      ko(ajaxError(err));
+    });
+  });
+}