Some pagedjs info

Recent pagedjs info sheet from Julien.

Paged.js explained

Paged.js is a free and open source JavaScript library that paginates content in the browser to create PDF output from any HTML content. This means you can design works for print (eg. books) using HTML and CSS.

Built on top of the HTML, CSS and JS standards, Paged.js won’t make assumptions about what a user wants to do: there won’t be any workaround to find something that should work by default. It works with any language supported by Unicode, and allow any CSS properties supported by the browser the book will be rendered in. Always up to date with the latest CSS and JS, the core team can focus on helping the community defining how HTML can be rendered on paper.

Paged.js is a community based project: while its main goal is to support the features the W3C defined in the specifications, the community can imagine new ideas and solutions that can easily be implemented as plugin to Paged.js.

Basic list of supported features (CSS)

  • Page number
  • Running heads
  • Bleeds and crop marks
  • Facing pages layout: different layout for left and right pages.
  • Page master based on the content (named page)
  • Support for different units (pt, mm, in, etc.)
  • Automatic layout for element in the margins
  • Cross references, table of content, index
  • Footnotes

## How does it works?

To generate a PDF, Pagedjs offers two solutions:

  1. A preview of the book, shown in the browser (used as )
  2. A server-side rendering app, that transforms a webpage into a PDF.

When Pagedjs is run on a webpage, it will check the content and its connected CSS styles to define how the layout will be. The main difference with the classic page layout tool is in how the content is paginated, not from the page number they end up on, but from the content itself. Since HTML is a marked up description of the content, we can define how a chapter title will look, on which page it will be (left, right or both), and define the page master used: for example: if you see a chapter title, make it on the right page, change the margins for that page only, add a background color, change the color for the title, etc. Page masters (the CSS styles for each type of page) will be automatically applied to the content (the HTML itself).

What can we do with Paged.js?

Following the existing paths: the existing specs from the W3C

Paged.js follows the specifications from the W3C that describe how the HTML and the CSS needs to be written to do a certain amount of things. While they seems a bit limiting, they actually offer a lot using a simple language easily understandable. All the following is made using only CSS, with the proper HTML markup.

On pages

  • In Paged.js, you can define any page size you need, in any unit supported by the W3C: inches, point, mm and even pixel.
    @page{size: A4} /* the page will be A4*/
    @page {size: 150mm 221mm} /* the page will be 150mm (width) × 221mm (height) */
  • Crop marks and bleeds.
@page {marks: crop cross; bleed: 3mm}
  • First page, right and left pages can have different layout. And you can also set a specific layout to any page selected by its number:
    @page: first {…} 
    
    @page :right {…}, 
    
    @page :left {…}, 
    
    @page:nth(12) {…}
  • Support for page-breaks (send to next page, next right page, next left page)
    /* send to next page */
    
    .chapter {
    break-before: page;
    }
    
    
    /* send to next right */
    
    .part {
    break-before: right;
    }
    
    
    /* send to left right */
    
    .left {
    break-before: left;
    }
  • Page created when a page break create an empty page can have a specific layout.
    @page :blank {…}
  • Page masters can also have their own styles
    /*
    if you want all your page in your chapter 
    section to have 30mm of top margin
    */
    
    section.chapter {
    /* set the pagemaster for the .chapter element the page master*/
     page: chapterMaster
    }
    
    @page chapterMaster {
     /* define the page master lauyout*/
     margin-top: 30mm
    }

On margins boxes: generated content

  • W3C defines page ass a set of areas: the page area that will contains the content and the margin-boxes, allowing the placement of automatic generated content. Generated content is based on the HTML itself and can be used to add counters to titles, running heads, page numbers, cross references, etc. In the case of the margin boxes, we can describe the artifacts used for printed books.

a

Page numbers
  • To add the page number on each page:
    @page { @bottom-right : counter(page)}
  • To show the total amount of page in the book:
    @page { @bottom-right: counter(pages)}
Running heads

Running heads can be set with two different ways:

  • copying the non formatted text of the element (its first letter, or something in the :before or :after element, such as title numbers)
    h2 {string-set: titleString string(content(text))}
    
    h2 {string-set: titleString string(content(first-letter))}
    h2 {string-set: titleString string(content(before))}
    h2 {string-set: titleString string(content(after))}
    
    @page {
      @bottom-left {
        content: string(titleString)
      }
    }

    If you have multiple elements on the page, you can select which one to use

    b

 

  • Moving the element out of the flow, and use it in a margin-box (that can include image, spans, italic, bold, etc.).
    h2 {
        position: running(titleRunning);
    }
    
    @page {
      @bottom-left {
        content: element(titleRunning)
      }
    }

Index, table of content, cross references: finding the right page

In the print space, a cross reference (“see figure 14 page 12”) is a link placed where the reference will be written down that will target the element referenced. To do so, we use the target-counter CSS property.

/* 
After a link, create a pseudo element, and give it the value of the page number the element is on 
*/
a.crossReference::after {
  content: target-counter(attr(href url), page) ;
}

/*
You can also mix it with some text:
*/

a.crossReference::after {
  content: "[see figure on page " target-counter(attr(href url), page)"]" ;
}

The exact same solution is used for any reference to an element on another page: table of content, indexes, etc.

Footnotes

Footnotes are coming to Paged.js. Making s. he callout and the footnote stick together on the same page is a pretty complex thing, especially with long footnotes. We’ll write down a complete explaination on how footnote work by the end of january 2021 to celebrate the release.

The specs for the footnotes from the w3c allow styles for the footnote counter and callout styles. It’s a bit basic, but it works fine. The core team of Paged.js also wrote a more complex bit about how notes could be handled in the future in Notes about Notes

/*
the placement of the footnote are defined in the @page
*/  
@page {
    @footnote {
        border-top: dashed red 1px;
        margin-top: 12px;
        float: bottom;
        }
}


/*
Each note element (in that case, a span with a class "footnote") is being send to the footnote zone using float
*/
span.footnote { 
    float: footnote;
}

/*
the style for the footnote call is added
*/
.footnote::footnote-call {
    color: red;
}


/*
the style for the footnote number is added
*/
.footnote::footnote-marker {
    color: blue;
}

Tables

Table seems easy at first, because they are pretty straightforward: but they can get very tricky when it comes to complex layout: columns spaning, table headers in the middle of the table, repeated table footer, etc.

The W3C doesn’t really explore what you can do with table when it comes to print. The only described feature is the automatic repeat of table header when a table is chunked on multiple pages. We have a great work coming on tables to add more support. For now Paged.js handle simple tables. More complex tables will need custom CSS.

Finding new ways with custom plugins

Paged.js is a modern and modular javascript library. If the first goal is to support the W3C specs, it also helps when creating custom layout or implement specifications not built yet.

In the Pagedjs world, those scripts are called hooks. To be used, they need to be added to the HTML, as script element.

Looking at the Atla’s Pagedjs hooks, we can find some examples of how the hooks can help to automate most of the work:

  • Automatically write chapter number in full letters (https://gitlab.pagedmedia.org/pagedjs-templates/atla/blob/master/src/js/atla.js#L260)
  • Make printable links (https://gitlab.pagedmedia.org/pagedjs-templates/atla/blob/master/src/js/atla.js#L364).
  • Add unbreakable spaces after articles in titles to keep nouns and articles on the same line (https://gitlab.pagedmedia.org/pagedjs-templates/atla/blob/master/src/js/atla.js#L374)
  • Using the image ratio we can build an automatic layout for images, by changing its CSS styles depending on the format (portrait, landscape or square) (https://gitlab.pagedmedia.org/pagedjs-templates/atla/blob/master/src/js/atla.js#L513)

There is also the possibility to reuse existing hooks by copying the script element in your project .

  • Index will check for specific attribute in the content to create an index for the whole content.
  • Table of content will look at the content to create a table of content.
  • Mathjax support will provide support for Math using Mathjax

AirBnb?

So, in my own personal journey to make sense of the housing market I have been feeling a little frustrated. All I hear from experts and non-experts is the same thing – “its going up and it can’t possibly go down”… I literally hear folks say “housing prices can’t go down in New Zealand”… also, no one seems to be taking account of the fact that we just experienced the largest fall in GDP over a quarter ever…even bigger than the great depression. Infact, quite the opposite, yesterday I heard someone in the industry try to tell me the economy is on fire…they also tried to tell me immigration is going to grow next year … I don’t buy it.

My gut feeling is that when all the experts are saying the same thing, then at least some of them must be wrong…

That leads me to really dodgy research and theorizing as I try to make sense of it myself.

Here are my latest anecdata…

  1. NZ seems to have a housing crisis it that we don’t have enough houses to go round – we have the lowest owner-occupier rates since the 1950s
  2. the rental market is crushed with not enough availability and rents being high (see same article above).

However…the most interesting stuff I am seeing is :

  1. there appears to be a huge growth in internal tourism, but it does not replace the amount of $ generated by the lost international visitors.
  2. International tourism is (was) NZ biggest product in terms of generating $ from overseas
  3. from 2013 to 2018 it seems the ‘shared accommodation’ (airbnb, book a bach etc) economy grew from occupying 8% of the total holiday accommodation market to somewhere between 12 and 20%
  4. small towns like Raglan has almost no rentals but a LOT of airbnb accommodation

So…could it be that the low interest rates is driving the big buy up, but it is being done by older NZers buying a second home? As this drives the prices up less and less new players can enter the market as the houses become unaffordable…

However… could it also be true that these folks can’t live in two places at once so they either renting their place out long term or using it as airbnb accom? Certainly in Raglan I think, looking at the listings, it is more likely they are listing these second houses in airbnb…

Also it seems the forecast is for growing unemployment. It also seems that NZ is recovering from the recession ok (2nd and third quarters had the biggest fall in GDP in history at -12%)…but we are not going to open the borders for 12-18 months…

My gut is that all this is related. I’d bet that the rising unemployment numbers and the ‘returning to normal’ overseas will see asymmetrical migration – a growing net immigration loss over 2021 as more and more folks leave because the world is back to normal but NZ doesn’t increase it’s intake because it continues to be very conservative when managing the virus. If this is the case it will be very bad for NZ.

Could that also mean less demand for holiday accom? Would that mean folks would be keener to rent out long term pushing the price of rent down and releasing some of the pressure off the rental market? Would that in turn also slow down the housing market? Does a really slow recovery bring house prices down even with low interest rates in play?

I have no idea…

Of course and I really don’t know what I’m talking about but I’d like to try and get a handle on whats going on as I don’t trust things when everyone is in agreement and yet no one can give me a good explanation as to why and my own anecdata doesn’t co-relate to these opinions…