BUG: JavaScript executed twice (#1439)

Fixes #1425, #1420, #482
py-pdf · Nov 20, 2022 · 03f82d2 · 03f82d2
1 parent 906c338
commit 03f82d2
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Showing 2 changed files with 22 additions and 32 deletions.
diff --git a/PyPDF2/_writer.py b/PyPDF2/_writer.py
@@ -420,39 +420,30 @@ def add_js(self, javascript: str) -> None:
         >>> output.add_js("this.print({bUI:true,bSilent:false,bShrinkToFit:true});")
         # Example: This will launch the print window when the PDF is opened.
         """
+        # Names / JavaScript prefered to be able to add multiple scripts
+        if "/Names" not in self._root_object:
+            self._root_object[NameObject(CA.NAMES)] = DictionaryObject()
+        names = cast(DictionaryObject, self._root_object[CA.NAMES])
+        if "/JavaScript" not in names:
+            names[NameObject("/JavaScript")] = DictionaryObject(
+                {NameObject("/Names"): ArrayObject()}
+            )
+            # cast(DictionaryObject, names[NameObject("/JavaScript")])[NameObject("/Names")] = ArrayObject()
+        js_list = cast(
+            ArrayObject, cast(DictionaryObject, names["/JavaScript"])["/Names"]
+        )
+
         js = DictionaryObject()
         js.update(
             {
                 NameObject(PA.TYPE): NameObject("/Action"),
                 NameObject("/S"): NameObject("/JavaScript"),
-                NameObject("/JS"): NameObject(f"({javascript})"),
+                NameObject("/JS"): TextStringObject(f"{javascript}"),
             }
         )
-        js_indirect_object = self._add_object(js)
-
         # We need a name for parameterized javascript in the pdf file, but it can be anything.
-        js_string_name = str(uuid.uuid4())
-
-        js_name_tree = DictionaryObject()
-        js_name_tree.update(
-            {
-                NameObject("/JavaScript"): DictionaryObject(
-                    {
-                        NameObject(CA.NAMES): ArrayObject(
-                            [create_string_object(js_string_name), js_indirect_object]
-                        )
-                    }
-                )
-            }
-        )
-        self._add_object(js_name_tree)
-
-        self._root_object.update(
-            {
-                NameObject("/OpenAction"): js_indirect_object,
-                NameObject(CA.NAMES): js_name_tree,
-            }
-        )
+        js_list.append(create_string_object(str(uuid.uuid4())))
+        js_list.append(self._add_object(js))
 
     def addJS(self, javascript: str) -> None:  # pragma: no cover
         """

diff --git a/tests/test_javascript.py b/tests/test_javascript.py
@@ -12,7 +12,7 @@
 
 @pytest.fixture()
 def pdf_file_writer():
-    reader = PdfReader(RESOURCE_ROOT / "crazyones.pdf")
+    reader = PdfReader(RESOURCE_ROOT / "issue-604.pdf")
     writer = PdfWriter()
     writer.append_pages_from_reader(reader)
     return writer
@@ -27,17 +27,16 @@ def test_add_js(pdf_file_writer):
     assert (
         "/JavaScript" in pdf_file_writer._root_object["/Names"]
     ), "add_js should add a JavaScript name tree under the name catalog."
-    assert (
-        "/OpenAction" in pdf_file_writer._root_object
-    ), "add_js should add an OpenAction to the catalog."
 
 
-def test_overwrite_js(pdf_file_writer):
+def test_added_js(pdf_file_writer):
     def get_javascript_name():
         assert "/Names" in pdf_file_writer._root_object
         assert "/JavaScript" in pdf_file_writer._root_object["/Names"]
         assert "/Names" in pdf_file_writer._root_object["/Names"]["/JavaScript"]
-        return pdf_file_writer._root_object["/Names"]["/JavaScript"]["/Names"][0]
+        return pdf_file_writer._root_object["/Names"]["/JavaScript"]["/Names"][
+            -2
+        ]  # return -2 in order to get the latest javascript
 
     pdf_file_writer.add_js("this.print({bUI:true,bSilent:false,bShrinkToFit:true});")
     first_js = get_javascript_name()
@@ -47,4 +46,4 @@ def get_javascript_name():
 
     assert (
         first_js != second_js
-    ), "add_js should overwrite the previous script in the catalog."
+    ), "add_js should add to the previous script in the catalog."