Manipulate PDF Document in Python via .NET

Manipulate PDF Document in Python

Validate PDF Document for PDF A Standard (A 1A and A 1B)

To validate a PDF document for PDF/A-1a or PDF/A-1b compatibility, use the Document class validate method. This method allows you to specify the name of the file in which the result is to be saved and the required validation type PdfFormat enumeration : PDF_A_1A or PDF_A_1B.

The following code snippet shows you how to validate PDF document for PDF/A-1A.

    import aspose.pdf as ap

    # Open document
    document = ap.Document(input_pdf)

    # Validate PDF for PDF/A-1a
    document.validate(output_xml, ap.PdfFormat.PDF_A_1A)

The following code snippet shows you how to validate PDF document for PDF/A-1b.

    import aspose.pdf as ap

    # Open document
    document = ap.Document(input_pdf)

    # Validate PDF for PDF/A-1a
    document.validate(output_xml, ap.PdfFormat.PDF_A_1B)

Working with TOC

Add TOC to Existing PDF

TOC in PDF stands for “Table of Contents.” It is a feature that allows users to quickly navigate through a document by providing an overview of its sections and headings.

To add a TOC to an existing PDF file, use the Heading class in the aspose.pdf namespace. The aspose.pdf namespace can both create new and manipulate existing PDF files. To add a TOC to an existing PDF, use the Aspose.Pdf namespace. The following code snippet shows how to create a table of contents inside an existing PDF file using Python via .NET.

    import aspose.pdf as ap

    # Load an existing PDF files
    doc = ap.Document(input_pdf)

    # Get access to first page of PDF file
    tocPage = doc.pages.insert(1)

    # Create object to represent TOC information
    tocInfo = ap.TocInfo()
    title = ap.text.TextFragment("Table Of Contents")
    title.text_state.font_size = 20
    title.text_state.font_style = ap.text.FontStyles.BOLD

    # Set the title for TOC
    tocInfo.title = title
    tocPage.toc_info = tocInfo

    # Create string objects which will be used as TOC elements
    titles = ["First page", "Second page", "Third page", "Fourth page"]
    for i in range(0, 2):
        # Create Heading object
        heading2 = ap.Heading(1)
        segment2 = ap.text.TextSegment()
        heading2.toc_page = tocPage
        heading2.segments.append(segment2)

        # Specify the destination page for heading object
        heading2.destination_page = doc.pages[i + 2]

        # Destination page
        heading2.top = doc.pages[i + 2].rect.height

        # Destination coordinate
        segment2.text = titles[i]

        # Add heading to page containing TOC
        tocPage.paragraphs.add(heading2)

    # Save the updated document
    doc.save(output_pdf)

Set different TabLeaderType for different TOC Levels

Aspose.PDF for Python also allows setting different TabLeaderType for different TOC levels. You need to set line_dash property of TocInfo.

    import aspose.pdf as ap

    doc = ap.Document()
    tocPage = doc.pages.add()
    toc_info = ap.TocInfo()

    # set LeaderType
    toc_info.line_dash = ap.text.TabLeaderType.SOLID
    title = ap.text.TextFragment("Table Of Contents")
    title.text_state.font_size = 30
    toc_info.title = title

    # Add the list section to the sections collection of the Pdf document
    tocPage.toc_info = toc_info
    # Define the format of the four levels list by setting the left margins
    # and
    # text format settings of each level

    toc_info.format_array_length = 4
    toc_info.format_array[0].margin.left = 0
    toc_info.format_array[0].margin.right = 30
    toc_info.format_array[0].line_dash = ap.text.TabLeaderType.DOT
    toc_info.format_array[0].text_state.font_style = ap.text.FontStyles.BOLD | ap.text.FontStyles.ITALIC
    toc_info.format_array[1].margin.left = 10
    toc_info.format_array[1].margin.right = 30
    toc_info.format_array[1].line_dash = 3
    toc_info.format_array[1].text_state.font_size = 10
    toc_info.format_array[2].margin.left = 20
    toc_info.format_array[2].margin.right = 30
    toc_info.format_array[2].text_state.font_style = ap.text.FontStyles.BOLD
    toc_info.format_array[3].line_dash = ap.text.TabLeaderType.SOLID
    toc_info.format_array[3].margin.left = 30
    toc_info.format_array[3].margin.right = 30
    toc_info.format_array[3].text_state.font_style = ap.text.FontStyles.BOLD

    # Create a section in the Pdf document
    page = doc.pages.add()

    # Add four headings in the section
    for Level in range(1, 5):
        heading2 = ap.Heading(Level)
        segment2 = ap.text.TextSegment()
        heading2.segments.append(segment2)
        heading2.is_auto_sequence = True
        heading2.toc_page = tocPage
        segment2.text = "Sample Heading" + str(Level)
        heading2.text_state.font = ap.text.FontRepository.find_font("Arial")

        # Add the heading into Table Of Contents.
        heading2.is_in_list = True
        page.paragraphs.add(heading2)

    # save the Pdf
    doc.save(output_pdf)

Hide Page Numbers in TOC

In case if you do not want to display page numbers, along with the headings in TOC, you can use is_show_page_numbers property of TocInfo Class as false. Please check following code snippet to hide page numbers in the table of contents:

    import aspose.pdf as ap

    doc = ap.Document()
    toc_page = doc.pages.add()
    toc_info = ap.TocInfo()
    title = ap.text.TextFragment("Table Of Contents")
    title.text_state.font_size = 20
    title.text_state.font_style = ap.text.FontStyles.BOLD
    toc_info.title = title
    # Add the list section to the sections collection of the Pdf document
    toc_page.toc_info = toc_info
    # Define the format of the four levels list by setting the left margins and
    # text format settings of each level

    toc_info.is_show_page_numbers = False
    toc_info.format_array_length = 4
    toc_info.format_array[0].margin.right = 0
    toc_info.format_array[0].text_state.font_style = ap.text.FontStyles.BOLD | ap.text.FontStyles.ITALIC
    toc_info.format_array[1].margin.left = 30
    toc_info.format_array[1].text_state.underline = True
    toc_info.format_array[1].text_state.font_size = 10
    toc_info.format_array[2].text_state.font_style = ap.text.FontStyles.BOLD
    toc_info.format_array[3].text_state.font_style = ap.text.FontStyles.BOLD
    page = doc.pages.add()
    # Add four headings in the section
    for Level in range(1, 5):
        heading2 = ap.Heading(Level)
        segment2 = ap.text.TextSegment()
        heading2.toc_page = toc_page
        heading2.segments.append(segment2)
        heading2.is_auto_sequence = True
        segment2.text = "this is heading of level " + str(Level)
        heading2.is_in_list = True
        page.paragraphs.add(heading2)
    doc.save(output_pdf)

Customize Page Numbers while adding TOC

It is common to customize the page numbering in the TOC while adding TOC in a PDF document. For example, we may need to add some prefix before page number like P1, P2, P3 and so on. In such a case, Aspose.PDF for Python provides page_numbers_prefix property of TocInfo class that can be used to customize page numbers as shown in the following code sample.

    import aspose.pdf as ap

    # Load an existing PDF files
    doc = ap.Document(input_pdf)
    # Get access to first page of PDF file
    toc_page = doc.pages.insert(1)
    # Create object to represent TOC information
    toc_info = ap.TocInfo()
    title = ap.text.TextFragment("Table Of Contents")
    title.text_state.font_size = 20
    title.text_state.font_style = ap.text.FontStyles.BOLD
    # Set the title for TOC
    toc_info.title = title
    toc_info.page_numbers_prefix = "P"
    toc_page.toc_info = toc_info
    for i in range(len(doc.pages)):
        # Create Heading object
        heading2 = ap.Heading(1)
        segment2 = ap.text.TextSegment()
        heading2.toc_page = toc_page
        heading2.segments.append(segment2)
        # Specify the destination page for heading object
        heading2.destination_page = doc.pages[i + 1]
        # Destination page
        heading2.top = doc.pages[i + 1].rect.height
        # Destination coordinate
        segment2.text = "Page " + str(i)
        # Add heading to page containing TOC
        toc_page.paragraphs.add(heading2)

    # Save the updated document
    doc.save(output_pdf)

How to set PDF expiry date

We apply access privileges on PDF files so that a certain group of users can access particular features/objects of PDF documents. In order to restrict the PDF file access, we usually apply encryption and we may have a requirement to set PDF file expiration, so that the user accessing/viewing the document gets a valid prompt regarding PDF file expiry.

    import aspose.pdf as ap

    # Instantiate Document object
    doc = ap.Document()
    # Add page to pages collection of PDF file
    doc.pages.add()
    # Add text fragment to paragraphs collection of page object
    doc.pages[1].paragraphs.add(ap.text.TextFragment("Hello World..."))
    # Create JavaScript object to set PDF expiry date
    javaScript = ap.annotations.JavascriptAction(
        "var year=2017;"
        + "var month=5;"
        + "today = new Date(); today = new Date(today.getFullYear(), today.getMonth());"
        + "expiry = new Date(year, month);"
        + "if (today.getTime() > expiry.getTime())"
        + "app.alert('The file is expired. You need a new one.');"
    )
    # Set JavaScript as PDF open action
    doc.open_action = javaScript

    # Save PDF Document
    doc.save(output_pdf)

Flatten Fillable PDF in Python

PDF documents often include forms with interactive fillable widgets such as radio buttons, checkboxes, text boxes, lists, etc. To make it uneditable for various application purposes, we need to flatten the PDF file. Aspose.PDF provides the function to flatten your PDF in Python with just few line of code:

    import aspose.pdf as ap

    # Load source PDF form
    doc = ap.Document(input_pdf)

    # Flatten Flatten Fillable PDF
    if len(doc.form.fields) > 0:
        for item in doc.form.fields:
            item.flatten()

    # Save the updated document
    doc.save(output_pdf)