To add a random string of characters in the specified format before each URL load into the iframe, we can adjust the code to generate a random string that adheres to your requirements. The string will retain the `_aem_` in its correct position.
Below is the updated code that includes this functionality:
### Updated Code with Fixed Position for `_aem_`
```html
Random URL Iframe Loader
Random URL Loader
### Explanation of Changes:
1. **Random String Generation**:
- The `generateRandomString` function now constructs a string that follows your specified format:
- It generates 27 characters before the fixed `_aem_` part.
- It generates 26 characters after the `_aem_` part.
- Combines them into the desired format with `_aem_` in the middle.
2. **Updating URLs**:
- When constructing the new URL, the generated random string is appended as a query parameter.
### Summary:
This updated code creates a random string of characters that maintains the specified format with `_aem_` at its fixed position, and appends this string to each URL loaded in the iframe. You can customize the length of the character sequences or the format further to fit additional requirements if needed.