introduce outputmanager to redirect output in repl

pyscriptjs/src/components/pyrepl.ts

@@ -202,28 +202,32 @@ export class PyRepl extends HTMLElement {
     async evaluate() {
         console.log('evaluate');
           let pyodide = await pyodideReadyPromise;
-          // debugger
+
           try {
             // @ts-ignore
-            let source = this.editor.state.doc.toString();
+            const sourceStrings = [`output_manager.change("`+this.editorOut.id+`")`, 
+              ...this.editor.state.doc.toString().split("\n")];
+            const source = sourceStrings.join('\n')
             let output;
+
             if (source.includes("asyncio")){
               output = await pyodide.runPythonAsync(source);
+              await pyodide.runPythonAsync(`output_manager.revert()`)
             }else{
               output = pyodide.runPython(source);
+              pyodide.runPython(`output_manager.revert()`)
             }
-
+            
             if (output !== undefined){
               let Element = pyodide.globals.get('Element');
               let out = Element(this.editorOut.id);
+
               // @ts-ignore
-              out.write(output);
-              out.write.callKwargs(output, { append : false});
+              out.write.callKwargs(output, { append : true});
 
               if (!this.hasAttribute('target')) {
                 this.editorOut.hidden =  false;
               }
-              // this.addToOutput(output);
             }
 
             if (this.hasAttribute('auto-generate')) {

pyscriptjs/src/interpreter.ts

@@ -8,7 +8,7 @@ let pyodide;
 let additional_definitions = `
 from js import document, setInterval, console
 import asyncio
-import io, base64
+import io, base64, sys
 
 loop = asyncio.get_event_loop()
 
@@ -95,7 +95,30 @@ class Element:
         
         return Element(clone.id, clone)
 
+class OutputManager:
+    def __init__(self, custom=None, output_to_console=True):
+        self._custom = custom
+        self.output_to_console = output_to_console
+        self.prev = None
+
+    def change(self, custom):
+        self._prev = self._custom
+        self._custom = custom
+        console.log("----> changed to", self._custom)
+
+    def revert(self):
+        console.log("----> reverted")
+        self._custom = self._prev
+
+    def write(self, txt):
+        if self._custom:
+            pyscript.write(self._custom, txt, append=True)
+        if self.output_to_console:
+            console.log(self._custom, txt)
+
 pyscript = PyScript()
+output_manager = OutputManager()
+sys.stdout = output_manager
 `
 
 let loadInterpreter = async function(): Promise<any> {