Code to merge two PDFs of scanned book: one of odd pages, the other of the even pages.

Hmm - in case the uploaded file is not available - here is the script:

function mergeAlternatePagesFromOpenDocs() {
try {
// Store reference to current document
var currentDoc = this;
var currentDocName = this.documentFileName;

// Get all currently open documents
var openDocs = [];
var docNames = [];

// Try to access open documents - this may require privileged context
if (typeof app.activeDocs === "undefined" || app.activeDocs === null) {
app.alert("Unable to access open documents.\n\nMake sure you have multiple PDFs open in Acrobat.", 1);
return;
}

// Collect all open documents except the current one
for (var i = 0; i < app.activeDocs.length; i++) {
var doc = app.activeDocs[i];
if (doc && doc.documentFileName !== currentDocName) {
openDocs.push(doc);
docNames.push(doc.documentFileName);
}
}

// Check if there are other open documents
if (openDocs.length === 0) {
app.alert("No other PDF documents are currently open.\n\nPlease open the PDF you want to merge with and try again.", 1);
return;
}

var selectedDoc = null;
var selectedIndex = -1;

// If only one other document is open, use it automatically
if (openDocs.length === 1) {
var response = app.alert("Merge with \"" + docNames[0] + "\"?\n\nDoc2 pages will be inserted in REVERSE order\n(Doc1-p1, Doc2-lastpage, Doc1-p2, Doc2-secondtolast, ...)", 2, 2);
if (response === 4) { // Yes button
selectedDoc = openDocs[0];
selectedIndex = 0;
} else {
app.alert("Operation cancelled.", 3);
return;
}
} else {
// Multiple documents open - let user choose
var dialog = {
selectedIdx: -1,

initialize: function(dialog) {
// Create list items object
var listItems = {};
for (var i = 0; i < docNames.length; i++) {
listItems[docNames[i]] = (-1);
}
dialog.load({
"list": listItems
});
},

commit: function(dialog) {
var results = dialog.store();
var listResults = results["list"];
for (var item in listResults) {
if (listResults[item] > 0) {
// Find the index by matching the name
for (var i = 0; i < docNames.length; i++) {
if (docNames[i] === item) {
this.selectedIdx = i;
break;
}
}
break;
}
}
},

description: {
name: "Select PDF to Merge",
align_children: "align_left",
width: 400,
height: 250,
elements: [
{
type: "static_text",
name: "Select a document to merge into \"" + currentDocName + "\":",
font: "dialog"
},
{
type: "list_box",
item_id: "list",
width: 380,
height: 150
},
{
type: "static_text",
name: "Selected document pages will be inserted in REVERSE order",
font: "dialog"
},
{
alignment: "align_fill",
type: "ok_cancel",
ok_name: "Merge",
cancel_name: "Cancel"
}
]
}
};

// Show the dialog
var dialogResult = app.execDialog(dialog);

if (dialogResult === "ok" && dialog.selectedIdx >= 0) {
selectedDoc = openDocs[dialog.selectedIdx];
selectedIndex = dialog.selectedIdx;
} else {
app.alert("Operation cancelled.", 3);
return;
}
}

// Verify we have a selected document
if (!selectedDoc || selectedIndex < 0) {
app.alert("No document selected. Operation cancelled.", 1);
return;
}

// Store the path of the selected document
var selectedDocPath = selectedDoc.path;
var selectedPages = selectedDoc.numPages;
var currentPages = currentDoc.numPages;

// Verify the path is valid
if (!selectedDocPath || selectedDocPath === "") {
app.alert("Warning: Document path not available. Attempting direct merge...", 3);
}

// Determine how many pairs we'll create
var maxPairs = Math.max(currentPages, selectedPages);

// Set up thermometer (progress bar)
var t = app.thermometer;
t.duration = maxPairs;
t.begin();

// We'll track the insertion offset as pages are added
var insertionOffset = 0;
var insertedCount = 0;

// Process each pair position
for (var i = 0; i < maxPairs; i++) {
try {
// For each position i:
// - Doc1 page is at index i (if it exists)
// - Doc2 page is at index (selectedPages - 1 - i) for reverse order

var doc2PageIndex = selectedPages - 1 - i;

// Only insert if Doc2 has a page at this position
if (doc2PageIndex >= 0) {
// Calculate where to insert this page
// It should go after the i-th page of doc1 (if it exists)
var insertPosition = i + 1 + insertionOffset;

// Make sure we don't exceed the document bounds
if (insertPosition > currentDoc.numPages) {
insertPosition = currentDoc.numPages;
}

// Insert the page from doc2 in reverse order
if (selectedDocPath && selectedDocPath !== "") {
currentDoc.insertPages(insertPosition - 1, selectedDocPath, doc2PageIndex, doc2PageIndex);
} else {
currentDoc.insertPages(insertPosition - 1, selectedDoc, doc2PageIndex, doc2PageIndex);
}

insertedCount++;
insertionOffset++; // We've added a page, so adjust offset
}

t.value = i;
t.text = 'Processing pair ' + (i + 1) + ' of ' + maxPairs;

} catch (pageError) {
console.println("Error inserting page from position " + doc2PageIndex + ": " + pageError.message);
// Continue with next page
}
}

// End thermometer
t.end();

// Check if any pages were inserted
if (insertedCount === 0) {
app.alert("Error: No pages could be inserted.\n\nThe selected document may be protected or corrupted.", 1);
return;
}

// Success message with example
var exampleText = "";
if (currentPages <= 3 && selectedPages <= 3) {
exampleText = "\n\nResult order example:\n";
for (var i = 0; i < currentPages; i++) {
exampleText += "Doc1-p" + (i + 1);
var revIndex = selectedPages - i;
if (revIndex > 0) {
exampleText += ", Doc2-p" + revIndex;
}
if (i < currentPages - 1) {
exampleText += ", ";
}
}
}

app.alert("Documents merged successfully!\n\n" +
"Original pages (Doc1): " + currentPages + "\n" +
"Inserted pages (Doc2): " + insertedCount + " of " + selectedPages + "\n" +
"Total pages: " + currentDoc.numPages +
exampleText, 3);

} catch (e) {
// More detailed error handling
var errorMsg = "Error: " + e.message;

if (e.message.indexOf("file") !== -1) {
errorMsg += "\n\nPossible causes:\n" +
"- The selected document may be protected\n" +
"- The file may be corrupted\n" +
"- Insufficient permissions\n\n" +
"Try saving both documents and reopening them.";
} else {
errorMsg += "\n\nMake sure you have at least two PDF documents open.";
}

app.alert(errorMsg, 1);
}
}

// Call the function
mergeAlternatePagesFromOpenDocs.call(this);

It worked for everybody else, so I would assume there is something wrong with your code. Are you getting any errors on the JavaScript console?

Hi Karl,

Thanks for making that so incredibly easy, that worked perfectly.

Carl