science

XSL Formatting Objects

XSL Formatting Objects is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand XSL Formatting Objects rather than just read about it. In short: XSL-FO (XSL Formatting Objects) is a markup language for XML document formatting that is most often used to generate PDF files. It has largely been superseded by the CSS3 but is still maintained for legacy systems.

Key takeaways

XSL Formatting Objects belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect XSL Formatting Objects to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of XSL Formatting Objects from memory before moving on to harder problems.

Reference excerpt

XSL-FO (XSL Formatting Objects) is a markup language for XML document formatting that is most often used to generate PDF files. It has largely been superseded by the CSS3 but is still maintained for legacy systems. It is an intermediary file format with the purpose of generating paged, printed media. The intended workflow is to transform an XML file into XSL-FO by writing and running a script in the XSLT programming language and then transform the XSL-FO file into PDF or other formats with a software called XSL-FO processor. The XSLT script only needs to be written once for each document type. The XSL-FO specification was originally published under the ambiguous title XSL 1.0 in October 2001 declaring XSLT to be the other half but only linking the 1999 XSLT specification rather than including it. Version 1.1 was published as XSL 1.1 in December 2006. The last update for the 2.0 Working Draft was in January 2012, and its Working Group closed in November 2013. The XSLT language itself was originally conceived only to transform to XSL-FO but is now used for more general XML transformations. The XSL-FO specification allows different FO processors to have varying responses with regard to the resultant generated pages. For example, different processors may even use different hyphenation algorithms, ranging from very simple to more complex hyphenation algorithms that take into account whether the previous or next line also is hyphenated. This can substantially change the layout. FO works best for a single flowing span of fairly contiguous text, with various repeating information built into the margins of a page. This is as opposed to complex layouts used in newspapers or magazines.

File structure The following is a minimalist XSL-FO file with only the required markup to show "Hello World".XSL-FO documents are XML documents, but they do not have to conform to any DTD or schema. Instead, they conform to a syntax defined in the XSL-FO specification. <fo:layout-master-set> details a list of named page layouts. <fo:page-sequence> is a list of document data, with markup, that uses the various page layouts to determine how the content fills the various pages. Layout masters define the properties of a page sequence. They can define the directions for the flow of text, so as to match the conventions for the language in question. They define the size of a page as well as the margins of that page. More importantly, they can define sequences of pages that allow for effects where the odd and even pages look different. For example, one can define a page layout sequence that gives extra space to the inner margins of a book. Page sequences are divided into flows and flows into blocks. Blocks can contain a contain text data and <fo:inline> elements. Content may also be added to the margins of the document, for page numbers, chapter headings and the like. Blocks and inline elements function similarly as in CSS, though some of the rules for padding and margins differ between FO and CSS. XSL-FO's basic content markup is derived from CSS and its cascading rules.

XSL-FO 1.0 In addition to the information as specified above, the following is supported:

Pages with multiple columns Lists Pagination controls: The user can specify Widow and Orphan for blocks or for the flow itself, and allow the attributes to cascade into child blocks. Additionally, blocks can be specified to be kept together on a single page. For example, an image block and the description of that image can be set to never be separated. The FO processor will do its best to adhere to these commands, even if it requires creating a great deal of empty space on a page. Footnotes Tables Text orientation controls: One can, in the middle of a page, designate a block of text to be oriented in a different orientation. Text direction for each element Page number citations. A page that contains a special tag can be cited in text, and the FO processor will fill in the actual page number where this tag appears. Block borders, in a number of styles. Background colors and images. Font controls and weighting, as in CSS. Side floats. Miscellaneous Inline Elements. Attribute propagation like in CSS

XSL-FO 1.1 New features:

Multiple flows and flow mapping: XSL-FO 1.0 was fairly restrictive about what text was allowed to go in what areas of a page. Version 1.1 loosens these restrictions significantly, allowing flowing text to be mapped into multiple explicit regions on a page. This allows for more newspaper-like typesetting. Named Bookmarks: Many output formats for XSL-FO processors, specifically PDF, have bookmarking features. These allow the format to specify a string of text in a separate window that can be selected by the user. When selected, the document window scrolls immediately to a specific region of the document. Indexing: features that support the generation of an index that might be found at the back of a book. This is done through referencing of properly marked-up elements in the FO document. Last page citation: The last page can be generated without providing an explicit in-document reference to a specific anchor in the FO document. The definition of "last page" can be restricted to within a specific set of pages or to cover the entire document. This allows the user to specify something like, "Page 2 out of 15", where page 15 is the page number of a last page definition. Table markers: Table markers allow the user to create dynamic content within table headers and footers, such as running totals at the bottom of each page of a table or "table continued" indicators. Inside/outside floats: adds the keywords "inside" and "outside" for side floats, which makes it possible to achieve page layouts with marginalia positioned on the outside or inside edges of pages. Inside refers to the side of the page towards the book binding, and outside refers to the side of a page away from the book binding. Refined graphic sizing: adds the ability to shrink graphics to fit (but not grow to fit), as well as the ability to define specific scaling steps. In addition, the resulting scaling factor can be referenced for display (for example, to say in a figure caption, "image shown is 50% actual size").

Limitations

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with XSL Formatting Objects

Start with the simplest possible case. Write down what XSL Formatting Objects claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to XSL Formatting Objects before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about XSL Formatting Objects ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of XSL Formatting Objects

In research: XSL Formatting Objects appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses XSL Formatting Objects in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: XSL Formatting Objects is common in secondary-school and first-year university syllabi. It links to neighbouring topics Markup languages, Page description languages, Typesetting programming languages, so understanding it makes those chapters shorter.
In everyday life: Look for XSL Formatting Objects outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “XSL Formatting Objects” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study XSL Formatting Objects in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what XSL Formatting Objects means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain XSL Formatting Objects out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is XSL Formatting Objects in simple terms?

Why does XSL Formatting Objects matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study XSL Formatting Objects?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on XSL Formatting Objects.