To generate a PDF using JavaScript in Oracle APEX from a collection

 To generate a PDF using JavaScript in Oracle APEX from a collection, you can follow these steps:

1. Create a button or link on your APEX page to trigger the PDF generation.
2. Add a dynamic action to the button or link to execute JavaScript code.
3. In the JavaScript code, retrieve the data from the collection and format it as needed.
4. Use a JavaScript library like jsPDF or pdfmake to generate the PDF document.
5. Download the generated PDF document.

Here's an example of how you can achieve this:

1. Create a button or link on your APEX page:
  - Button Name: "Generate PDF"
  - Button Action: "Defined by Dynamic Action"

2. Add a dynamic action to the button or link:
  - Event: "Click"
  - Action: "Execute JavaScript Code"

3. In the JavaScript code, retrieve the data from the collection and format it:
```javascript
// Retrieve data from the collection
var collectionData = apex.collection.get('YOUR_COLLECTION_NAME');

// Format the data as needed
var formattedData = '';
for (var i = 0; i < collectionData.length; i++) {
 formattedData += collectionData[i].column1 + ' - ' + collectionData[i].column2 + '\n';
}
```

4. Use a JavaScript library like jsPDF or pdfmake to generate the PDF document:
  - Include the library in your APEX application (e.g., by uploading the library file to the Static Application Files).
  - Use the library's API to create and format the PDF document based on the formatted data.

Here's an example using jsPDF:
```javascript
// Generate the PDF document
var doc = new jsPDF();
doc.text(formattedData, 10, 10);

// Save the PDF document
doc.save('generated_pdf.pdf');
```

5. Download the generated PDF document:
  - The `doc.save('generated_pdf.pdf')` line in the above code will automatically download the PDF document with the specified filename.

Make sure to replace `'YOUR_COLLECTION_NAME'` with the actual name of your collection, and adjust the formatting and PDF generation code as per your requirements.

Note: Ensure that you have the necessary permissions and libraries set up in your Oracle APEX environment to execute JavaScript code and generate PDF documents.