jsAppend

Inserts the specified content after the existing response body. (This only works if the content-type response type contains javascript and the status code includes a response body (e.g., 200/500).)

⚠️ Note: Requests without a response body, such as 204 and 304, are not affected.

Rule Syntax

pattern jsAppend://value [filters...]

Parameters	Description	Detailed Documentation
pattern	An expression to match against the request URL	Match Pattern Documentation
value	Text or binary content. The following types are supported: • Directory/File Path • Remote URL • Inline/Embedded/Values Content	Operation Instruction Documentation
filters	Optional filters. Supports matching: • Request URL/Method/Headers/Content • Response Status Code/Headers	Filter Documentation

Configuration Example

Inline Method

www.example.com/path1 jsAppend://(Hello) file://(-test-)
www.example.com/path2 jsAppend://(Hello) file://(-test-) resType://js
www.example.com/path3 jsAppend://(Hello) file://(-test-) resType://css

• Requesting https://www.example.com/path1/to results in a response of -test-<script>Hello</script>
• Requesting https://www.example.com/path2/to results in a response of -test-Hello
• Requesting https://www.example.com/path3/to results in a response of -test-

Embedded/Values Method

``` body.txt
Hello world.
```
www.example.com/path1 jsAppend://{body.txt} file://(-test-)
www.example.com/path2 jsAppend://{body.txt} file://(-test-) resType://js
www.example.com/path3 jsAppend://{body.txt} file://(-test-) resType://css

• Requesting https://www.example.com/path1/to results in a response of -test-<script>Hello world.</script>
• Requesting https://www.example.com/path2/to results in a response of -test-Hello world.
• Requesting https://www.example.com/path3/to results in a response of -test-

Local/Remote Resources

www.example.com/path1 jsAppend:///User/xxx/test.js
www.example.com/path2 jsAppend://https://www.xxx.com/xxx/params.js
# Editing a temporary file
www.example.com/path3 jsAppend://temp/blank.js

Set <script> Tag Attributes for Injected Scripts

Scripts injected into HTML pages via jsAppend are automatically wrapped in <script> tags by Whistle. To set additional attributes for these tags—such as nomodule, module, defer, async, or crossorigin—you can use the lineProps parameter for configuration.

www.example.com/path1 jsAppend://https://www.xxx.com/xxx/params.js lineProps://nomodule
www.example.com/path2 jsAppend://https://www.xxx.com/xxx/params.js lineProps://module
www.example.com/path3 jsAppend://https://www.xxx.com/xxx/params.js lineProps://defer
www.example.com/path4 jsAppend://https://www.xxx.com/xxx/params.js lineProps://async
www.example.com/path5 jsAppend://https://www.xxx.com/xxx/params.js lineProps://crossorigin

Attribute Descriptions and Examples

Attribute	Purpose	Configuration Example
nomodule	Executes in traditional browsers; this script will run in browsers that do not support ES modules.	lineProps://nomodule
module	Declares the script as an ES module, enabling modular imports.	lineProps://module
defer	Loads asynchronously and executes after the document has been parsed.	lineProps://defer
async	Loads asynchronously and executes immediately after download.	lineProps://async
crossorigin	Enables Cross-Origin Resource Sharing (CORS) mode.	lineProps://crossorigin

Associated Protocols

1. Inject content before the response content (Prepend To Body): resPrepend
2. Inject HTML content before the response content (Prepend HTML To Body, response type must be text/html): htmlPrepend
3. Inject CSS content before the response content (Prepend CSS To Body, response type must be text/html or text/css): cssPrepend
4. Inject JS content before the response content (Prepend JS To Body, response type must be text/html, text/css, or application/javascript): jsPrepend
5. Replace the response content (Replace Body): resBody
6. Replace the response content with HTML content (Replace Body, response type must be text/html): htmlBody
7. Replace the response content with CSS content (Replace Body, response type must be text/html or text/css): cssBody
8. Replace the response content with JS content (Replace Body, response type must be text/html, text/css, or application/javascript): jsBody
9. Append content after the response content (Append To Body): resAppend
10. Append HTML content after the response content (Append HTML To Body, response type must be text/html): htmlAppend
11. Append CSS content after the response content (Append CSS To Body, response type must be text/html or text/css): cssAppend
12. Append JS content after the response content (Append JS To Body, response type must be text/html, text/css, or application/javascript): jsAppend
13. Replace the response content using keywords or regular expressions (Modify Body Text): resReplace
14. Override JSON/Form objects in the response content (Modify Form/JSON): resMerge
15. Delete a property from a JSON/Form object in the response content (Delete Form/JSON): delete://resBody.xxx