allow adding a custom prefix to file package downloads, so they can happen from a different url; fixes #2049

2 files changed, 43 insertions, 4 deletions

diff --git a/tests/test_browser.py b/tests/test_browser.py
index 02bcecbd..2c9407db 100644
--- a/tests/test_browser.py
+++ b/tests/test_browser.py
@@ -580,6 +580,45 @@ If manually bisecting:
     shutil.rmtree(os.path.join(self.get_dir(), 'subdirr'))
     self.run_browser('page.html', 'You should see two cool numbers', '/report_result?1')
 
+  def test_custom_file_package_url(self):
+    # a few files inside a directory
+    self.clear()
+    os.makedirs(os.path.join(self.get_dir(), 'subdirr'));
+    os.makedirs(os.path.join(self.get_dir(), 'cdn'));
+    open(os.path.join(self.get_dir(), 'subdirr', 'data1.txt'), 'w').write('''1214141516171819''')
+    # change the file package base dir to look in a "cdn". note that normally you would add this in your own custom html file etc., and not by
+    # modifying the existing shell in this manner
+    open(self.in_dir('shell.html'), 'w').write(open(path_from_root('src', 'shell.html')).read().replace('var Module = {', 'var Module = { filePackageURL: "cdn/", '))
+    open(os.path.join(self.get_dir(), 'main.cpp'), 'w').write(self.with_report_result(r'''
+      #include <stdio.h>
+      #include <string.h>
+      #include <emscripten.h>
+      int main() {
+        char buf[17];
+
+        FILE *f = fopen("subdirr/data1.txt", "r");
+        fread(buf, 1, 16, f);
+        buf[16] = 0;
+        fclose(f);
+        printf("|%s|\n", buf);
+        int result = !strcmp("1214141516171819", buf);
+
+        REPORT_RESULT();
+        return 0;
+      }
+    '''))
+
+    def test():
+      Popen([PYTHON, EMCC, os.path.join(self.get_dir(), 'main.cpp'), '--shell-file', 'shell.html', '--preload-file', 'subdirr/data1.txt', '-o', 'test.html']).communicate()
+      shutil.move('test.data', os.path.join('cdn', 'test.data'))
+      self.run_browser('test.html', '', '/report_result?1')
+
+    test()
+
+    # TODO: CORS, test using a full url for filePackageURL
+    #open(self.in_dir('shell.html'), 'w').write(open(path_from_root('src', 'shell.html')).read().replace('var Module = {', 'var Module = { filePackageURL: "http:/localhost:8888/cdn/", '))
+    #test()
+
   def test_compressed_file(self):
     open(os.path.join(self.get_dir(), 'datafile.txt'), 'w').write('compress this please' + (2000*'.'))
     open(os.path.join(self.get_dir(), 'datafile2.txt'), 'w').write('moar' + (100*'!'))
diff --git a/tools/file_packager.py b/tools/file_packager.py
index 8b65b219..6c60db58 100644
--- a/tools/file_packager.py
+++ b/tools/file_packager.py
@@ -462,7 +462,7 @@ if has_preloaded:
 
   package_uuid = uuid.uuid4();
   remote_package_name = os.path.basename(Compression.compressed_name(data_target) if Compression.on else data_target)
-  code += r'''
+  ret += r'''
     var PACKAGE_PATH;
     if (typeof window === 'object') {
       PACKAGE_PATH = window['encodeURIComponent'](window.location.pathname.toString().substring(0, window.location.pathname.toString().lastIndexOf('/')) + '/');
@@ -471,7 +471,7 @@ if has_preloaded:
       PACKAGE_PATH = encodeURIComponent(location.pathname.toString().substring(0, location.pathname.toString().lastIndexOf('/')) + '/');
     }
     var PACKAGE_NAME = '%s';
-    var REMOTE_PACKAGE_NAME = '%s';
+    var REMOTE_PACKAGE_NAME = (Module['filePackageURL'] || '') + '%s';
     var PACKAGE_UUID = '%s';
   ''' % (data_target, remote_package_name, package_uuid)
 
@@ -666,7 +666,7 @@ if has_preloaded:
     # Only tricky bit is the fetch is async, but also when runWithFS is called is async, so we handle both orderings.
     ret += r'''
       var fetched = null, fetchedCallback = null;
-      fetchRemotePackage('%s', function(data) {
+      fetchRemotePackage(REMOTE_PACKAGE_NAME, function(data) {
         if (fetchedCallback) {
           fetchedCallback(data);
           fetchedCallback = null;
@@ -674,7 +674,7 @@ if has_preloaded:
           fetched = data;
         }
       }, handleError);
-    ''' % os.path.basename(Compression.compressed_name(data_target) if Compression.on else data_target)
+    '''
 
     code += r'''
       Module.preloadResults[PACKAGE_NAME] = {fromCache: false};