Merge pull request #654 from coolreader18/wasm-explicit-stdout

[WASM] Make setStdout arguments more explicit in what they print to

wasm/demo/src/main.js

@@ -36,7 +36,15 @@ function runCodeFromTextarea() {
     const code = editor.getValue();
     try {
         const result = rp.pyEval(code, {
-            stdout: '#console'
+            stdout: output => {
+                const shouldScroll =
+                    consoleElement.scrollHeight - consoleElement.scrollTop ===
+                    consoleElement.clientHeight;
+                consoleElement.value += output;
+                if (shouldScroll) {
+                    consoleElement.scrollTop = consoleElement.scrollHeight;
+                }
+            }
         });
         if (result !== null) {
             consoleElement.value += `\n${result}\n`;
@@ -74,57 +82,58 @@ snippets.addEventListener('change', updateSnippet);
 // option selected for the `select`, but the textarea won't be updated)
 updateSnippet();
 
-const prompt = ">>>>> ";
+const prompt = '>>>>> ';
 
 const term = new Terminal();
 term.open(document.getElementById('terminal'));
 term.write(prompt);
 
 function removeNonAscii(str) {
-    if ((str===null) || (str===''))
-        return false;
-    else
-        str = str.toString();
+    if (str === null || str === '') return false;
+    else str = str.toString();
 
     return str.replace(/[^\x20-\x7E]/g, '');
 }
 
 function printToConsole(data) {
-    term.write(removeNonAscii(data) + "\r\n");
+    term.write(removeNonAscii(data) + '\r\n');
 }
 
-const terminalVM = rp.vmStore.init("term_vm");
+const terminalVM = rp.vmStore.init('term_vm');
 terminalVM.setStdout(printToConsole);
 
-var input = "";
-term.on("data", (data) => {
-  const code = data.charCodeAt(0);
-  if (code == 13) { // CR
-    if (input[input.length - 1] == ':') {
-        input += data
-        term.write("\r\n.....");
-    } else {
-        term.write("\r\n");
-        try {
-            terminalVM.exec(input);
-        } catch (err) {
-            if (err instanceof WebAssembly.RuntimeError) {
-                err = window.__RUSTPYTHON_ERROR || err;
+var input = '';
+term.on('data', data => {
+    const code = data.charCodeAt(0);
+    if (code == 13) {
+        // CR
+        if (input[input.length - 1] == ':') {
+            input += data;
+            term.write('\r\n.....');
+        } else {
+            term.write('\r\n');
+            try {
+                terminalVM.exec(input);
+            } catch (err) {
+                if (err instanceof WebAssembly.RuntimeError) {
+                    err = window.__RUSTPYTHON_ERROR || err;
+                }
+                printToConsole(err);
             }
-            printToConsole(err);
+            term.write(prompt);
+            input = '';
         }
-        term.write(prompt);
-        input = "";
+    } else if (code == 127) {
+        if (input.length > 0) {
+            term.write('\b \b');
+            input = input.slice(0, -1);
+        }
+    } else if (code < 32 || code == 127) {
+        // Control
+        return;
+    } else {
+        // Visible
+        term.write(data);
+        input += data;
     }
-  } else if (code == 127) {
-    if (input.length > 0) {
-        term.write("\b \b");
-        input = input.slice(0, -1);
-    }
-  } else if (code < 32 || code == 127) { // Control
-    return;
-  } else { // Visible
-    term.write(data);
-    input += data;
-  }
 });

wasm/lib/Cargo.toml

@@ -26,7 +26,6 @@ features = [
     "console",
     "Document",
     "Element",
-    "HtmlTextAreaElement",
     "Window",
     "Headers",
     "Request",

wasm/lib/src/vm_class.rs

@@ -11,7 +11,7 @@ use rustpython_vm::{
 use std::cell::RefCell;
 use std::collections::HashMap;
 use std::rc::{Rc, Weak};
-use wasm_bindgen::prelude::*;
+use wasm_bindgen::{prelude::*, JsCast};
 
 pub trait HeldRcInner {}
 
@@ -271,13 +271,16 @@ impl WASMVirtualMachine {
                       ref mut scope,
                       ..
                   }| {
+                fn error() -> JsValue {
+                    TypeError::new("Unknown stdout option, please pass a function or 'console'")
+                        .into()
+                }
                 let print_fn: Box<Fn(&mut VirtualMachine, PyFuncArgs) -> PyResult> =
-                    if let Some(selector) = stdout.as_string() {
-                        Box::new(
-                            move |vm: &mut VirtualMachine, args: PyFuncArgs| -> PyResult {
-                                wasm_builtins::builtin_print_html(vm, args, &selector)
-                            },
-                        )
+                    if let Some(s) = stdout.as_string() {
+                        match s.as_str() {
+                            "console" => Box::new(wasm_builtins::builtin_print_console),
+                            _ => return Err(error()),
+                        }
                     } else if stdout.is_function() {
                         let func = js_sys::Function::from(stdout);
                         Box::new(
@@ -291,12 +294,12 @@ impl WASMVirtualMachine {
                             },
                         )
                     } else if stdout.is_undefined() || stdout.is_null() {
-                        Box::new(wasm_builtins::builtin_print_console)
+                        fn noop(vm: &mut VirtualMachine, _args: PyFuncArgs) -> PyResult {
+                            Ok(vm.get_none())
+                        }
+                        Box::new(noop)
                     } else {
-                        return Err(TypeError::new(
-                            "stdout must be null, a function or a css selector",
-                        )
-                        .into());
+                        return Err(error());
                     };
                 scope.store_name(&vm, "print", vm.ctx.new_rustfunc(print_fn));
                 Ok(())

wasm/lib/src/wasm_builtins.rs

@@ -4,43 +4,16 @@
 //! desktop.
 //! Implements functions listed here: https://docs.python.org/3/library/builtins.html.
 
-use crate::convert;
 use js_sys::{self, Array};
 use rustpython_vm::obj::{objstr, objtype};
 use rustpython_vm::pyobject::{IdProtocol, PyFuncArgs, PyObjectRef, PyResult, TypeProtocol};
 use rustpython_vm::VirtualMachine;
-use wasm_bindgen::{prelude::*, JsCast};
-use web_sys::{self, console, HtmlTextAreaElement};
+use web_sys::{self, console};
 
 pub(crate) fn window() -> web_sys::Window {
     web_sys::window().expect("Window to be available")
 }
 
-// The HTML id of the textarea element that act as our STDOUT
-
-pub fn print_to_html(text: &str, selector: &str) -> Result<(), JsValue> {
-    let document = window().document().expect("Document to be available");
-    let element = document
-        .query_selector(selector)?
-        .ok_or_else(|| js_sys::TypeError::new("Couldn't get element"))?;
-    let textarea = element
-        .dyn_ref::<HtmlTextAreaElement>()
-        .ok_or_else(|| js_sys::TypeError::new("Element must be a textarea"))?;
-
-    let value = textarea.value();
-
-    let scroll_height = textarea.scroll_height();
-    let scrolled_to_bottom = scroll_height - textarea.scroll_top() == textarea.client_height();
-
-    textarea.set_value(&format!("{}{}", value, text));
-
-    if scrolled_to_bottom {
-        textarea.scroll_with_x_and_y(0.0, scroll_height.into());
-    }
-
-    Ok(())
-}
-
 pub fn format_print_args(vm: &mut VirtualMachine, args: PyFuncArgs) -> Result<String, PyObjectRef> {
     // Handle 'sep' kwarg:
     let sep_arg = args
@@ -93,12 +66,6 @@ pub fn format_print_args(vm: &mut VirtualMachine, args: PyFuncArgs) -> Result<St
     Ok(output)
 }
 
-pub fn builtin_print_html(vm: &mut VirtualMachine, args: PyFuncArgs, selector: &str) -> PyResult {
-    let output = format_print_args(vm, args)?;
-    print_to_html(&output, selector).map_err(|err| convert::js_to_py(vm, err))?;
-    Ok(vm.get_none())
-}
-
 pub fn builtin_print_console(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     let arr = Array::new();
     for arg in args.args {