How to Extract Digits from a PDF Drop-Down List Using JavaScript
Question details
The user needs to use an Acrobat JavaScript calculation script to extract the first two digits from a PDF drop-down selection and display them elsewhere.
- Product
- Device & OS
- not provided
- Scenario
- Creating an interactive PDF form where selecting an option containing a code and description automatically extracts just the numerical code into a separate destination text field.
- Observed behavior
- The user wants to parse the string from the drop-down menu and capture only the first two characters using JavaScript.
Ensure you have access to a PDF editor that supports form field editing and custom JavaScript execution, and identify the exact field name of your source drop-down menu before writing the script.
Use a Custom Calculation Script to Extract Digits
Apply a JavaScript substring method in the destination text field's calculation properties to automatically pull the first two characters from your drop-down list.
When your drop-down options contain both a numerical code and a text description (for example, '12 - Sales Department'), you can isolate the code using the JavaScript `substring` method. This custom script must be placed in the destination field where you want the extracted digits to appear, rather than the drop-down field itself.
Right-click your source drop-down menu in form editing mode, select 'Properties', and note the exact name of the field (e.g., 'Dropdown1').
Right-click the destination text field where you want the extracted digits to appear, and click on 'Properties'.
In the Text Field Properties dialog, select the 'Calculate' tab.
Select the 'Custom calculation script' option, click 'Edit', and enter the following code: event.value = this.getField("Dropdown1").valueAsString.substring(0,2);
Click 'OK' to save the script, close the properties dialog, and test your form by selecting an option from the drop-down to ensure the digits appear in the text field.
Edit and Manage Interactive PDF Forms Easily with WPS Office
WPS Office provides powerful PDF tools that allow you to fill, edit, and manage interactive PDF forms seamlessly. It's a fantastic solution for handling document workflows efficiently.
- 1. Open WPS PDF: Launch WPS Office and click on 'PDF' to open the dedicated PDF editor.
- 2. Load your PDF Form: Click 'Open' and select the interactive PDF form file you need to work on.
- 3. Interact with Form Fields: Navigate to the 'Form' tab or simply click into the highlighted text fields and drop-downs to input your data or view auto-calculated fields.
- 4. Save your Document: Once your form is filled or modified, click the 'Save' icon to preserve your data securely.
Frequently Asked Questions
Why is my JavaScript calculation script not updating the destination field?
This usually happens due to a typo in the field name. Ensure that the field name referenced in your script (e.g., 'Dropdown1') perfectly matches the actual field name in your PDF properties. JavaScript is case-sensitive, meaning 'Dropdown1' and 'dropdown1' are treated as two different fields.
Can I extract characters from the end of the drop-down string instead of the beginning?
Yes, you can modify the JavaScript to capture characters from the end of the string. Instead of using substring(0,2), you can use the slice method, such as valueAsString.slice(-2), to capture the last two characters of the selection.
Will the substring method cause an error if the selected drop-down option has fewer than two characters?
No. The JavaScript substring method will simply return all available characters up to the end of the string. If the string is shorter than the requested range, it will output the exact string without throwing an error.
