Research/Web-to-print/WeasyPrint

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Revision as of 09:23, 26 November 2015 by Andre (talk | contribs) (→‎Running)

Print in hybrid publishing workflows

Print products = bottleneck in hybrid publishing workflows

Screens in pages represent different paradigms

  • Instead of reflowable text, continuous space, variable screen size
  • Page: a fixed space

The translation of layouts for screen to page layouts, within is not trivial.

HTML-to-print Tools

LaTex

A type-setting/document preparation language, focused on producing typographicaly correct PDFs.

positive aspects

  • LaTex is a markup language;
  • Pandoc converts seamlessly to LaTex.
  • Supports page numbers, hyphenation, bibliography, references, hyperlinks, etc, etc...
  • Can produce more experimental and generative outputs. [1].

negative aspects

  • Outputs are by default look academic, although this can be changed
  • Use is outmoded
  • Styling is defined by packages imported into the document, which is very different and incompatible with CSS.
  • A difficult tool to work with, let alone to teach.


Browser built-in pdf rendering

Current browsers have built-in pdf rendering engines. By using the browser function «Print to file» and CSS rules for print, print layouts can be created from HTML files.

positive aspects

  • relies on the same set of technologies - HTML, CSS and JS - as other hybrid publishing formats: webpages, ePubs, apps
  • it is simple, easily to teach
  • CSS includes page specific options: @media page rule, and the pseudo-classes :first :left :right @bottom-left

negative aspects

  • works poorly and inconsistently
  • requires a lot of trial-and-error to achieve the desired output, with results differing widely across browsers and versions

* difficult to avoid page breaks breaking and hiding content.

show example

Desktop publishing software

Software such as Scribus and inDesign can be incorporated into an HP workflow.

Scribus can import HTML files and inDesign ICML(XML)files. Both formats keep their structure when imported and can remain updatable.

positive aspects

  • allows direct feedback between operations and their effects
  • graphic designers are familiar their workflows
  • can produce complex PDFs with impositions, hyphenation, page numbers. etc
  • can intervene in almost all aspects of the document

negative aspects

  • to keep the content updatable operations (in inDesign) interventions on content are not possible
  • complex structures, like large tables, are difficult to handle, while keeping content updatable (in inDesign)


Weasy Print

Weasy Print (WP)[2] is a visual rendering engine for HTML and CSS that can export to PDF.

Its CSS layout engine is written in Python, but employs several libraries to render the HTML and CSS onto a PDF.


positive aspects

  • Uses HTML and CSS to layout the PDF
  • Supports features like page size, page numbering, hyphenation in several languages [3]
  • Resulting PDFs can achieve high level of complexity, with simple instructions
  • Simple and easy to use
  • Can be used as a Python library or as a standalone program
  • Free software (BSD license)

negative aspects

  • Can be difficult to install, due to its dependencies
  • It does not support CSS custom fonts
  • No support for folded formats, such as booklets: no mechanism for imposition




What is Weasy Print

Weasy Print (WP) is


Testing Weasy Print

At the first glance Weasy Print sounds promising, so why not try to see how well does it performs conversions from HTML to PDF and what CSS rules does it apply consistently.

The following PDF results from the conversion of the Beyond Social's article Eiland van Brienenoord onto a PDF using Weasy Print.

The CSS style-sheet that gave origin the PDF is located at the of this page

Web2print-BS07.pdf

Running

The standalone command weasyprint can produce a PDF, simply with the instructions:

weasyprint EilandvanBrienenoord.html -s style.css ouput.pdf

Where:

  • EilandvanBrienenoord.html - is the souce HTML file (could also be a URL)
  • -s - is the option for a CSS stylesheet
  • ouput.pdf - the resulting PDF

@page

@page left @page right @bottom-right

page counter

CSS Custom Fonts

  • @page rule - define the page dimensions prototype02 - works
  • @media print - weasyprint follows @media print
  • @page left; @page right - protype04
    • @bottom-right - prototype05
  • page number counter - prototype06
  • CUSTOM FONTS - font-face is not supported. But WeasyPrint should pick up any

font that Pango/fontconfig are able to find.

examples of works with weasy
try table



CSS style-sheet

@page {
size: A5 portrait;
}

@page:right {
  margin-left: 3cm; /*inner*/
  margin-right:1cm; /*outer*/ 
  
  @bottom-right {
    margin: 10pt 0 30pt 0;
    border-top: .25pt solid #FF05F6;
    content: "Testing WeasyPrint";
    font-size: 6pt;
    color: #00FFF2;
  }
  
  @bottom-center {
    margin: 10pt 0 30pt 0;
    content: counter(page);
    font-size: 6pt;
  }

}

@page:left {
  margin-right: 3cm; /*inner*/
  margin-left:1cm; /*outer*/

  @bottom-left {
    margin: 10pt 0 30pt 0;
    border-top: .25pt solid #00FFF2;
    content: "Testing WeasyPrint";
    font-size: 6pt;
    color: #FF05F6;
  }

  @bottom-center {
    margin: 10pt 0 30pt 0;
    content: counter(page);
    font-size: 6pt;
  }


}
 
@page:first {
  
  
  @bottom-center {
    content: "";
  }
  
    @bottom-right {
    content: "";
  }
  
  
}



body{
  font-size:8pt;
  font-family: sans;  
  padding: 0.5cm;
  }

a, a:visited, a:hover {color:#00FFF2;}

hr { color:#00FFF2;
   border:solid 1px #00FFF2;
}

div.title-beyond h1 {font-size:4em;
  margin-top:-40px;
} /*title*/

h1,h2,h3,h4,h5 {color:#FF05F6;  
}


figure {
  margin-left:0px;
  padding-top:0.5cm;  
}
  
img{
  width: 6cm;
}

figcaption { font-size:0.8em;
  width:6cm;
}

references

  1. See works by Lafkon studio for an idea of the possibilities
  2. “WeasyPrint Documentation” http://weasyprint.org/docs/.
  3. With the pyphen library