Difference between revisions of "Research/Web-to-print/WeasyPrint"

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=Print in hybrid publishing workflows=
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==Print in hybrid publishing workflows==
'''Print products = bottleneck in hybrid publishing workflows'''
'''Print products = bottleneck in hybrid publishing workflows'''


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


=HTML-to-print Tools=
==HTML-to-print Tools==
* LaTex
* Browser built-in PDF rendering
* Desktop publishing software
* Weasy Print.


==LaTex==
==LaTex==
Line 37: Line 43:
* works poorly and inconsistently
* works poorly and inconsistently
* requires a lot of trial-and-error to achieve the desired output, with results differing widely across browsers and versions
* requires a lot of trial-and-error to achieve the desired output, with results differing widely across browsers and versions
<s>* difficult to avoid page breaks breaking and hiding content.  
 
: show example  </s>
===OSP===
[http://osp.kitchen/ OSP] is making a lot of efforts in this area.
 
html2print tool (recently developed)
http://lurk.org/groups/80c/messages/topic/4CIuW3jpiAFLwllZN3itFV/


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




==Weasy Print==
==Weasy Print==
Weasy Print (WP)<ref name="weasyprint1">“WeasyPrint Documentation” http://weasyprint.org/docs/.</ref> is a visual rendering engine for HTML and CSS that can export to PDF.  
[[Weasy_Print]] (WP)<ref name="weasyprint1">“WeasyPrint Documentation” http://weasyprint.org/docs/.</ref> is a visual rendering engine for HTML to PDF, that uses CSS.  


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


===positive aspects===
===positive aspects===
* Uses HTML and CSS to layout the PDF
* Uses HTML and CSS to layout the PDF
* Supports features like page size, page numbering, hyphenation in several languages <ref name="hyp">With the [http://pyphen.org/ pyphen library]</ref>
* Supports features like page size, page numbering, hyphenation in several languages<ref name="hyp">With the [http://pyphen.org/ pyphen library]</ref>
* Resulting PDFs can achieve high level of complexity, with simple instructions
* Resulting PDFs can achieve high level of complexity, with simple instructions
* Simple and easy to use
* Simple and easy to use
* Can be used as a Python library or as a standalone program
* Can be used as a Python library or as a standalone program
* Free software (BSD license)
* Free software (BSD license)
* Clean documentation
* Cleal documentation
 
===negative aspects===
===negative aspects===
* Can be difficult to install, due to its dependencies
* Can be difficult to install, due to its dependencies
* It does not support CSS custom fonts
* It does not support CSS custom fonts - uses [http://www.pango.org/ Pango library] to manage fonts
* No support for folded formats, such as booklets: no mechanism for imposition
* No support for folded formats, such as booklets: no mechanism for imposition




 
[[Category:Research]]
=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?
 
The following PDF results from the conversion of the [http://beyond-social.org/ Beyond Social's] article [http://beyond-social.org/articles/Eiland_van_Brienenoord.html ''Eiland van Brienenoord''] onto a PDF using Weasy Print.
 
The CSS style-sheet that gave origin the PDF is [[#CSS style-sheet|located at the of this page]]
[[File:web2print-BS07.pdf]]
 
==Running==
The standalone command <code>weasyprint</code> can produce a PDF, simply with the instructions:
weasyprint EilandvanBrienenoord.html -s style.css ouput.pdf
 
Where:
* <code>EilandvanBrienenoord.html</code> - is the souce HTML file (could also be a URL)
* <code>-s</code> - is the option for a CSS stylesheet
* <code>ouput.pdf</code> - the resulting PDF
 
== @page ==
@page CSS rule that determines orientation and page size is successfully rendered in the PDF.
 
<source lang="css">
@page {
size: A5 portrait;
}
</source>
 
==  @page left @page right ==
So are specific option for the left and right pages, such as the margin sizes, which have to alternate in order to produce a bound work.
 
<source lang="css">
@page:right {
  margin-left: 3cm; /*inner margin*/
  margin-right:1cm; /*outer margin*/
}
 
@page:left {
  margin-right: 3cm; /*inner margin*/
  margin-left:1cm; /*outer margin*/
}
</source>
 
[[File:weasyprint-margins.png|600px]]
 
== @bottom ==
Weasy-print also applies consistently  <code>@bottom</code> rules, including page counting.
 
<source lang="css">
  @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;
  }
</source>
 
 
== CSS Custom Fonts ==
Weasy Print does not support CSS's (<code>@font-face</code>) rule.
 
To use custom fonts it relies on Pango library <ref name"pango">http://www.pango.org/</ref> for text layout.
 
A discussion on the use of custom fonts can be followed on Weasy Print's [https://github.com/Kozea/WeasyPrint/issues/231 Github issue]  
 
== Imposition ==
There appears to be no mechanism that performs page impositions.
 
Although it is possible to perform imposition over the Weasy Print-generated PDF with software such as [http://kjo.herbesfolles.org/bookletimposer/ BookletImposer], [http://jpdftweak.sourceforge.net/ jPDF Tweak], [https://github.com/raffamaiden/pdftools pdftool], or [https://www.pdflabs.com/tools/pdftk-the-pdf-toolkit/ PDFtk].
 
[[File:web2print-BS07-booklet.pdf|Booklet produced with BookletImposer, having Weasy Print generated PDF as source]]
 
=== more tests ===
These tests and prototypes are far from exhaustive.
 
It is still unclear weather Weasy Print, CSS and HTML can produce quality PDFs, ready to send to a printer in order to produce paper-bound publication.
 
The results are promising.
 
Yet more experimentation, prototypes, and feedback is needed in order to make a informed critique.
 
And contributions to [https://github.com/Kozea/WeasyPrint/ Weasy Print], will only help.
 
==CSS style-sheet==
<source lang="css">
@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;
}
</source>
 
 
=tutorials/posts on Weasy Print=
http://diethardsteiner.github.io/reporting/2015/02/17/CSS-for-print.html
 
=references=
<references/>

Latest revision as of 16:24, 17 April 2016

<slidy theme="a" />

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
  • Browser built-in PDF rendering
  • Desktop publishing software
  • Weasy Print.

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

OSP

OSP is making a lot of efforts in this area.

html2print tool (recently developed) http://lurk.org/groups/80c/messages/topic/4CIuW3jpiAFLwllZN3itFV/

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 to PDF, that uses CSS.

Its CSS layout engine is written in Python, but employs several libraries to render the 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)
  • Cleal documentation

negative aspects

  • Can be difficult to install, due to its dependencies
  • It does not support CSS custom fonts - uses Pango library to manage fonts
  • No support for folded formats, such as booklets: no mechanism for imposition
  1. ↑ See works by Lafkon studio for an idea of the possibilities
  2. ↑ “WeasyPrint Documentation” http://weasyprint.org/docs/.
  3. ↑ With the pyphen library
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