Testing out PDF generation

demo_doc.py

from io import BytesIO

from reportlab.lib.enums import TA_JUSTIFY
from reportlab.lib.pagesizes import letter
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.platypus import BaseDocTemplate, Paragraph, Spacer, PageTemplate, Frame


# Common text
LOREM = (
    "Lorem Ipsum is simply dummy text of the printing and typesetting industry. "
    "Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, "
    "when an unknown printer took a galley of type and scrambled it to make a type "
    "specimen book. It has survived not only five centuries, but also the leap into "
    "electronic typesetting, remaining essentially unchanged. It was popularised in "
    "the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, "
    "and more recently with desktop publishing software like Aldus PageMaker including "
    "versions of Lorem Ipsum."
)
HELLO = "Hello World is another language"
HELLO_MULTI = ". ".join([HELLO for _ in range(40)]) + "."

# Common styles
STYLES = getSampleStyleSheet()
STYLES.add(ParagraphStyle(name="Justify", alignment=TA_JUSTIFY))
NORM_STYLE = STYLES["Normal"]
H1_STYLE = STYLES["Heading1"]


def context(canvas, doc):
    """Establish header and footer contexts."""
    canvas.saveState()

    # Establish header
    P = build_p("This is a multi-line header. It goes on every page. " * 5, font_size=6)
    w, h = P.wrap(doc.width, doc.topMargin)
    P.drawOn(canvas, doc.leftMargin, doc.height + doc.topMargin)

    # Establish footer
    P = build_p("This is a multi-line footer. It goes on every page. " * 5, font_size=6)
    w, h = P.wrap(doc.width, doc.bottomMargin)
    P.drawOn(canvas, doc.leftMargin, h)

    canvas.restoreState()


def build_text(content: str, font_size: int = 8):
    """Build text with certain font."""
    pre = f"<font size={font_size}>"
    post = "</font>"
    return pre + content + post


def build_p(content: str, font_size: int = 8):
    """Build <p> paragraph."""
    return Paragraph(build_text(content, font_size=font_size), NORM_STYLE)


def build_h1(content: str, font_size: int = 8):
    """Build <h1> paragraph."""
    return Paragraph(build_text(content, font_size=font_size), H1_STYLE)


def build_space():
    return Spacer(1, 12)


def main():
    """Main logic of the program."""
    output = BytesIO()
    doc = BaseDocTemplate(
        output,
        pagesize=letter,
        rightMargin=72,
        leftMargin=72,
        topMargin=72,
        bottomMargin=72,
    )

    # Define a page template
    frame = Frame(
        doc.leftMargin, doc.bottomMargin, doc.width, doc.height - 20, id="normal"
    )
    template = PageTemplate(id="tbase", frames=frame, onPage=context)
    doc.addPageTemplates([template])

    # Generate content
    Story = []
    for i in range(10):
        Story.append(build_p(LOREM))
        Story.append(build_space())
        Story.append(build_p(HELLO_MULTI))
        Story.append(build_space())

    # Save file contents
    doc.build(Story)

    # Pass bytes into open file
    with open("demo_doc.pdf", "wb") as f:
        f.write(output.getvalue())


if __name__ == "__main__":
    main()

Resources.md

Official links:

• User guide as PDF
• Official code snippets

Codebase links:

• platypus.doctemplate
• platypus.flowables
• pdfgen.canvas
• docco.rltemplate

Community links:

• ReportLab step-by-step
• ReportLab tables
• ReportLab mixed content
• SO: Carriage Return
• SO: Multiline header and footer
• SO: Internal links
• SO: Custom fonts
• SO: Items on same row
• SO: Different next page
• Colored ReportLab Frames
• deeplook/svglib