Merge pull request #983 from plotly/dbg-r-reload

Dbg r reload

Author: byronz

CHANGELOG.md

@@ -2,6 +2,10 @@
 All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
+## Unreleased
+### Fixed
+- [#983](https://github.com/plotly/dash/pull/983) Fix the assets loading issues when dashR application runner is handling with an app defined by string chunk.
+
 ## [1.5.1] - 2019-10-29
 ### Fixed
 - [#987](https://github.com/plotly/dash/pull/987) Fix cache string handling for component suites with nested folders in their packages.

dash/testing/application_runners.py

@@ -5,6 +5,7 @@
 import uuid
 import shlex
 import threading
+import shutil
 import subprocess
 import logging
 import inspect
@@ -61,6 +62,7 @@ def __init__(self, keep_open, stop_timeout):
         self.started = None
         self.keep_open = keep_open
         self.stop_timeout = stop_timeout
+        self._tmp_app_path = None
 
     def start(self, *args, **kwargs):
         raise NotImplementedError  # pragma: no cover
@@ -103,6 +105,10 @@ def url(self):
     def is_windows(self):
         return sys.platform == "win32"
 
+    @property
+    def tmp_app_path(self):
+        return self._tmp_app_path
+
 
 class ThreadedRunner(BaseDashRunner):
     """Runs a dash application in a thread.
@@ -261,13 +267,18 @@ def start(self, app, start_timeout=2, cwd=None):
                 cwd = os.path.dirname(app)
                 logger.info("RRunner inferred cwd from app path: %s", cwd)
         else:
-            path = (
-                "/tmp/app_{}.R".format(uuid.uuid4().hex)
-                if not self.is_windows
-                else os.path.join(
-                    (os.getenv("TEMP"), "app_{}.R".format(uuid.uuid4().hex))
-                )
+            self._tmp_app_path = os.path.join(
+                "/tmp" if not self.is_windows else os.getenv("TEMP"),
+                uuid.uuid4().hex,
             )
+            try:
+                os.mkdir(self.tmp_app_path)
+            except OSError:
+                logger.exception(
+                    "cannot make temporary folder %s", self.tmp_app_path
+                )
+            path = os.path.join(self.tmp_app_path, "app.R")
+
             logger.info("RRunner start => app is R code chunk")
             logger.info("make a temporary R file for execution => %s", path)
             logger.debug("content of the dashR app")
@@ -283,11 +294,11 @@ def start(self, app, start_timeout=2, cwd=None):
                 for entry in inspect.stack():
                     if "/dash/testing/" not in entry[1].replace("\\", "/"):
                         cwd = os.path.dirname(os.path.realpath(entry[1]))
+                        logger.warning("get cwd from inspect => %s", cwd)
                         break
             if cwd:
                 logger.info(
-                    "RRunner inferred cwd from the Python call stack: %s",
-                    cwd
+                    "RRunner inferred cwd from the Python call stack: %s", cwd
                 )
             else:
                 logger.warning(
@@ -297,16 +308,40 @@ def start(self, app, start_timeout=2, cwd=None):
                     "dashr.run_server(app, cwd=os.path.dirname(__file__))"
                 )
 
+            # try copying all valid sub folders (i.e. assets) in cwd to tmp
+            # note that the R assets folder name can be any valid folder name
+            assets = [
+                os.path.join(cwd, _)
+                for _ in os.listdir(cwd)
+                if not _.startswith("__")
+                and os.path.isdir(os.path.join(cwd, _))
+            ]
+
+            for asset in assets:
+                target = os.path.join(
+                    self.tmp_app_path, os.path.basename(asset)
+                )
+                if os.path.exists(target):
+                    logger.debug("delete existing target %s", target)
+                    shutil.rmtree(target)
+                logger.debug("copying %s => %s", asset, self.tmp_app_path)
+                shutil.copytree(asset, target)
+                logger.debug("copied with %s", os.listdir(target))
+
         logger.info("Run dashR app with Rscript => %s", app)
+
         args = shlex.split(
-            "Rscript {}".format(os.path.realpath(app)),
+            "Rscript -e 'source(\"{}\")'".format(os.path.realpath(app)),
             posix=not self.is_windows,
         )
         logger.debug("start dash process with %s", args)
 
         try:
             self.proc = subprocess.Popen(
-                args, stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=cwd
+                args,
+                stdout=subprocess.PIPE,
+                stderr=subprocess.PIPE,
+                cwd=self.tmp_app_path if self.tmp_app_path else cwd,
             )
             # wait until server is able to answer http request
             wait.until(