How to Display Part of an Acrobat Alert Message in Red in PDFs
Question details
The user wants to format a specific portion of a PDF form error message in red using the app.alert script.
- Product
- Adobe Acrobat / PDF Forms
- Device & OS
- not provided
- Scenario
- Creating an interactive PDF form script where an error message needs to alert the user with mixed text colors.
- Observed behavior
- The standard Acrobat app.alert function outputs plain text and leaves the remaining text in the default color, failing to apply the requested rich-text formatting.
Ensure you are using a PDF editor with form authoring and JavaScript execution capabilities, and verify that your document is saved as an interactive PDF form.
Use an Interactive Rich Text Form Field
Since app.alert cannot display rich text, you can use a hidden form field on the PDF that appears with formatted red text when an error occurs.
The standard Acrobat JavaScript app.alert method only processes plain text strings. To show colored text, you must rely on objects within the PDF that natively support rich-text formatting.
Open your PDF in form editing mode and insert a Text Field near the area where the user inputs data.
Right-click the newly created text field, select 'Properties', navigate to the 'Options' tab, and check the box for 'Allow Rich Text Formatting'.
Modify your PDF script so that instead of calling app.alert, it changes this text field's visibility to visible and assigns the specific red-colored formatting to its richValue property.
Create a Custom Dialog Box
Implement a custom JavaScript dialog to gain more control over the interface than the default app.alert allows.
Edit and Manage PDF Forms with WPS Office
If you need to create, edit, or fill interactive PDF forms without dealing with complex JavaScript workarounds, WPS Office provides an intuitive suite of PDF tools that simplify document management.
- 1. Open your PDF in WPS Office: Launch WPS Office and open your interactive PDF document using the WPS PDF tool.
- 2. Access form tools: Click on the 'Form' tab in the top navigation bar to reveal all interactive form control options.
- 3. Customize form properties: Double-click any text field to adjust its appearance, text color, and formatting options directly from the properties panel.
Frequently Asked Questions
Can I use HTML tags inside an Acrobat app.alert?
No, the standard Acrobat app.alert function only accepts and renders plain text. Any HTML tags included in the string will be displayed as raw text rather than formatted content.
Why does my PDF script fail when trying to change alert text color?
The app.alert method in PDF JavaScript API does not have parameters or properties for text color or font styles. The API relies on the default system or application UI rendering.
How do I make a text field visible only when an error occurs?
You can set the form field's initial property to 'Hidden'. Then, in your validation script, use JavaScript to change the field's 'display' property to visible (e.g., display.visible) when the error condition is met.
