repository·main·Indexed 19 days ago
https://github.com/jhaygood86/peachpdfA pure .NET 8+ library for rendering HTML, MHTML, and local files into PDF documents without external dependencies like headless browsers. It features support for Flexbox, CSS Math, SVG vector rendering, and Tagged PDF (PDF/UA) output. The library is trimming-safe, Native AOT compatible, and includes a standalone command-line tool and a Blazor WebAssembly demo for client-side rendering.
PeachPDF is a pure .NET library (requires .NET 8+) that renders HTML to PDF without external processes like Puppeteer or wkhtmltopdf.
Key Features:
calc, min, max, clamp), 2D/3D transforms, Gradients, and CSS Custom Properties.@page rules, named pages, margin boxes, and running headers/footers via string-set/string().PdfGenerateConfig.EnableTaggedPdf and automatic metadata extraction from <title> and <meta>.PeachPDF uses a multi-layered testing approach to ensure rendering accuracy, as PDF token presence does not always guarantee visual correctness. The strategy includes:
PeachPDF is licensed under the BSD 3-Clause license. However, it embeds and adapts several third-party components directly within its source tree. If you are redistributing PeachPDF or its components, you must comply with the specific licenses of these embedded parts:
src/PeachPDF/PdfSharpCore/.src/PeachPDF/CSS/.src/PeachPDF/Text/Resources/Bidi/.The rendering process follows these stages:
PdfGenerator initializes a PdfDocument using settings from PdfGenerateConfig (page size, orientation, etc.).@page margin overrides are resolved from the stylesheet.XGraphicsPdfRenderer translates drawing calls into PDF content stream operators, handling the coordinate flip from CSS top-left to PDF bottom-left.PdfDocument is returned and can be saved to any Stream.PeachPDF supports a full CSS selector engine for styling SVG elements. Styling follows the standard CSS cascade rules with the following precedence (from highest to lowest):
style= attributes: style="fill: red;" on an element.<style> element rules: Rules defined within a <style> block, matched via selectors.fill="red".The engine supports a wide range of selectors:
rect.foo, #foo (Note: SVG selectors are case-sensitive).rect.foog rect), child (.wrap > circle), and sibling combinators.[gradientUnits="userSpaceOnUse"], [data-x^="a"].:first-child, :nth-of-type(), :only-of-type, :not(), :empty (where :empty matches elements with no children other than whitespace), and :only-of-type.!important overrides normal declarations.var() custom properties, calc(), min(), max(), and clamp() are fully resolved.@property are honored, including initial-value, inherits flags, and syntax validation.initial, inherit, unset, and revert are supported on SVG paint/geometry properties.<svg>: Participates in the host document's cascade. Rules in the HTML document's <style> or <link> tags will apply to the SVG shapes.<img src="x.svg"> or data:image/svg+xml): Acts as an independent document. It is only styled by its own internal <style> rules; host-document CSS cannot reach it.PeachPDF is designed for modern .NET deployment patterns:
IsTrimmable to ensure it works with the .NET trimmer.IsAotCompatible and uses source-generated LibraryImport marshalling instead of reflection-based DllImport. This allows you to publish fully native, self-contained executables using PublishTrimmed or PublishAot without additional configuration.PeachPDF uses a custom fork of ExCSS integrated directly into the source tree to allow the engine full access to parsed token and rule structures. This enables efficient selector resolution and immediate support for new CSS properties.
Parsed stylesheets contain a collection of the following rule types:
StyleRule: Regular selector + declaration blockMediaRule: @media (wraps child rules)FontFaceRule: @font-faceImportRule: @importContainerRule: @containerKeyframesRule: @keyframes (parsed but not animated)ViewportRule: @viewportDocumentRule: @documentWhen using a table inside a multi-column container, there are specific behaviors for spanning cells:
vertical-align property of a spanning cell resolves against the specific fragment on the page where the cell began, rather than against the entire height of the cell. For example, vertical-align: middle will center content within that specific page fragment.PeachPDF is designed for thread safety by using an instance-scoped model.
PdfGenerator instance across multiple threads.PdfGenerator per thread.While PdfGenerator is not thread-safe, the underlying process-wide state is protected:
GlyphTypefaceCache) are guarded by a reentrant monitor (Lock.EnterFontFactory()) to allow concurrent resolution from different generator instances.PeachPDF supports CSS multi-column layouts. You can control the number of columns, their width, and how content is distributed.
Key behaviors:
column-span: all on a direct child of the multi-column container to break the flow. The element will render at the full width of the container, splitting the columns before and after it. Note that this only works on direct children; it has no effect on deeper descendants.column-fill: balance (default): Distributes content evenly across columns using a binary search for minimum height.column-fill: auto: Fills each column to capacity before starting the next.<table> or other layout engine containers) will be placed in a column whole. If the element is taller than the column height, the column will grow to accommodate it rather than clipping the overflow.column-rule (shorthand for width, style, and color) to render vertical lines between columns..container {
column-count: 3;
column-gap: 1em;
column-rule: 1px solid black;
column-fill: balance;
}
.spanning-header {
column-span: all;
}When using break-before (or legacy page-break-before) or break-after (or legacy page-break-after), the break property propagates outward to the container.