Java PDFBox: Remove the parent element in tagged PDF

Question

I got the Possibly inappropriate use of a "Table" structure element warning in PAC3 validation. Table structure in PDF as follows,

In order to pass the PAC3 I now drag out the tables from the parent tag to an element on its own as like below,

I tried the below code, but it didn't work

PDStructureElement parent=(PDStructureElement)element.getParent();

//parent.setStructureType(StandardStructureTypes.TABLE);
element.insertBefore(element,parent);
element.setParent(parent.getParent());

Please help me with this.

Please use this PDF, https://drive.google.com/file/d/1Z1R-SIalxPzAHH57_Qs0zGPDV3rjoqtN/view — Dilli, Sep 04 '21 at 06:24
One question first, are you sure you try to manipulate the right element? At first glance PAC3 complains about a `Table` element inside an `Inline_Table` element, not as in your screenshot inside a `Footnote_Inline_Tabl` element. Also there appear to be other issues in the tag structure which PAC3 does not report. — mkl, Sep 05 '21 at 15:40
That been said, as you want to insert `element` into the grand parent's kids, you should try `parent.getParent().insertBefore` instead of `element.insertBefore`. — mkl, Sep 05 '21 at 16:25

score 1 · Accepted Answer · answered Sep 07 '21 at 08:49

The main issue in the code you show is that you try to insert the element as kid of itself instead of as kid of its current grand parent:

element.insertBefore(element,parent);

You can make it work like this:

if (element instanceof PDStructureElement) {
    PDStructureElement pdStructureElement = (PDStructureElement) element;
    if ("Table".equals(pdStructureElement.getStructureType())) {
        PDStructureNode parentNode = pdStructureElement.getParent();
        if (parentNode instanceof PDStructureElement) {
            PDStructureElement parent = (PDStructureElement) parentNode;
            PDStructureNode newParentNode = parent.getParent();
            if (newParentNode != null) {
                newParentNode.insertBefore(pdStructureElement, parent);
                pdStructureElement.setParent(newParentNode);
                newParentNode.removeKid(parent);
            }
        }
    }
}

(from MoveInStructureTree helper method checkAndMoveTableUp)

Applying this recursively to the structure tree of your PDF removes the Possibly inappropriate use of a "Table" structure element warning in PAC3 validation, cf. the MoveInStructureTree test testMoveTableUpTradeSimple1.

(This code assumes that like in your example document all Table elements are embedded as single kid in a parent element to replace. For other cases you have to add some sanity checks and probably special treatment of other cases.)

Java PDFBox: Remove the parent element in tagged PDF

1 Answers1