Cropping PDF pages using JavaScript

1// config.js
2const docViewer = instance.docViewer;
3const rotation = instance.CoreControls.PageRotation;
4
5docViewer.on('documentLoaded', async () => {
6  const doc = docViewer.getDocument();
7  const cropTop = 100, cropLeft = 0, cropRight = 0, cropBottom = 0;
8  const page1 = 1, page2 = 2, page3 = 3;
9
10  doc.getPageInfo(page1); // {width: 612, height: 792}
11
12  await doc.cropPages([page1], cropTop, cropBottom, cropLeft, cropRight)
13  doc.getPageInfo(page1); // {width: 612, height: 692}
14
15  await doc.rotatePages([page1], rotation.E_90);
16  docViewer.rotateCounterClockwise(page1);
17  doc.getPageInfo(page1); // {width: 692, height: 612}, width and height get swapped
18
19  // rotate the first page back so that it appears upright in the viewer
20  await doc.cropPages([page1], cropTop, cropBottom, cropLeft, cropRight);
21  doc.getPageInfo(page1); // {width: 692, height: 512}
22  // Even though the page appears upright, the document is rotated 90 degree clockwise
23  // So the left side of the document is cropped
24});

1// config.js
2const docViewer = instance.docViewer;
3const rotation = instance.CoreControls.PageRotation;
4
5docViewer.on('documentLoaded', async () => {
6  const doc = docViewer.getDocument();
7  const cropTop = 100, cropLeft = 0, cropRight = 0, cropBottom = 0;
8  const page1 = 1, page2 = 2, page3 = 3;
9
10  doc.getPageInfo(page1 - 1); // {width: 612, height: 792}
11
12  await doc.cropPages([page1], cropTop, cropBottom, cropLeft, cropRight)
13  doc.getPageInfo(page1); // {width: 612, height: 692}
14
15  await doc.rotatePages([page1], rotation.e_90);
16  docViewer.rotateCounterClockwise(page1);
17  doc.getPageInfo(page1 - 1); // {width: 692, height: 612}, width and height get swapped
18
19  // rotate the first page back so that it appears upright in the viewer
20  await doc.cropPages([page1], cropTop, cropBottom, cropLeft, cropRight);
21  doc.getPageInfo(page1 - 1); // {width: 692, height: 512}
22  // Even though the page appears upright, the document is rotated 90 degree clockwise
23  // So the left side of the document is cropped
24});