Introduction

In addition to the high-level PsDocument and XpsDocument classes, Aspose.Page FOSS for Python exposes a set of lower-level utilities for building render documents, writing PDF output, and working with XPS packages programmatically. These utilities are used internally by the high-level classes and can also be used directly when you need precise control over the output.

This article covers RenderModelBuilder, PdfWriter, PdfMetadata, RasterRenderer, and XpsDocumentBuilder — the common components shared across PS, EPS, and XPS pipelines.


Building a Render Document

RenderModelBuilder constructs a RenderDocument incrementally by calling page lifecycle methods. Start a page with begin_page(), add drawing commands, then call end_page(). Call document() to retrieve the completed RenderDocument.

from aspose.page.render.model import RenderModelBuilder

builder = RenderModelBuilder()
builder.begin_page(595, 842)
# add paths, text, images here
builder.end_page()
doc = builder.document()

Available drawing methods include add_path(), add_text(), add_image(), clip(), save_state(), and restore_state(). Call set_default_page_size() before begin_page() to establish a default size that applies to all subsequent pages.


Writing a Render Document to PDF

PdfWriter accepts a PdfMetadata instance and serializes a RenderDocument to PDF 1.4 bytes. Pass a PdfMetadata object with title, creator, producer, creation_date, mod_date, and trapped fields, then call write(doc) to produce the output.

from aspose.page.render.model import RenderModelBuilder
from aspose.page.pdf.writer import PdfWriter
from aspose.page.pdf.metadata import PdfMetadata
from pathlib import Path

builder = RenderModelBuilder()
builder.begin_page(595, 842)
builder.end_page()
doc = builder.document()

metadata = PdfMetadata(
    title="My Document",
    creator="My App",
    producer="Aspose.Page FOSS for Python",
    creation_date="D:20260609000000",
    mod_date="D:20260609000000",
    trapped=False,
)
writer = PdfWriter(metadata)
pdf_bytes = writer.write(doc)
Path("output.pdf").write_bytes(pdf_bytes)

Raster Rendering

RasterRenderer renders a RenderDocument to a RasterSurface — an in-memory RGBA pixel buffer. The RasterSurface provides get_pixel() and set_pixel() for direct pixel access, along with width and height properties. This is the underlying mechanism used by to_image() on both PsDocument and XpsDocument when producing PNG or JPEG output.

from aspose.page.render.model import RenderModelBuilder
from aspose.page.image.raster_renderer import RasterRenderer

builder = RenderModelBuilder()
builder.begin_page(400, 300)
builder.end_page()
doc = builder.document()

renderer = RasterRenderer()
surface = renderer.render(doc, page_index=0)
print(f"Surface size: {surface.width}x{surface.height}")

Building XPS Documents Programmatically

XpsDocumentBuilder provides a high-level API for constructing XPS packages with custom pages and metadata. Use create_page() to add pages, then call to_document() to obtain an XpsDocument that can be further exported to PDF or raster images.

from aspose.page.xps.document import XpsDocument

xps = XpsDocument.create("My XPS Document")
page = xps.add_page(595, 842)

Getting Started