mirror of
https://github.com/adambard/learnxinyminutes-docs.git
synced 2024-11-24 06:53:08 +03:00
181 lines
4.8 KiB
Markdown
181 lines
4.8 KiB
Markdown
---
|
|
language: haml
|
|
filename: learnhaml.haml
|
|
contributors:
|
|
- ["Simon Neveu", "https://github.com/sneveu"]
|
|
---
|
|
|
|
Haml is a markup language predominantly used with Ruby that cleanly and simply describes the HTML of any web document without the use of inline code. It is a popular alternative to using Rails templating language (.erb) and allows you to embed Ruby code into your markup.
|
|
|
|
It aims to reduce repetition in your markup by closing tags for you based on the structure of the indents in your code. The result is markup that is well-structured, DRY, logical, and easier to read.
|
|
|
|
You can also use Haml on a project independent of Ruby, by installing the Haml gem on your machine and using the command line to convert it to html.
|
|
|
|
$ haml input_file.haml output_file.html
|
|
|
|
|
|
```haml
|
|
/ -------------------------------------------
|
|
/ Indenting
|
|
/ -------------------------------------------
|
|
|
|
/
|
|
Because of the importance indentation has on how your code is rendered, the
|
|
indents should be consistent throughout the document. Any differences in
|
|
indentation will throw an error. It's common-practice to use two spaces,
|
|
but it's really up to you, as long as they're constant.
|
|
|
|
|
|
/ -------------------------------------------
|
|
/ Comments
|
|
/ -------------------------------------------
|
|
|
|
/ This is what a comment looks like in Haml.
|
|
|
|
/
|
|
To write a multi line comment, indent your commented code to be
|
|
wrapped by the forward slash
|
|
|
|
-# This is a silent comment, which means it wont be rendered into the doc at all
|
|
|
|
|
|
/ -------------------------------------------
|
|
/ Html elements
|
|
/ -------------------------------------------
|
|
|
|
/ To write your tags, use the percent sign followed by the name of the tag
|
|
%body
|
|
%header
|
|
%nav
|
|
|
|
/ Notice no closing tags. The above code would output
|
|
<body>
|
|
<header>
|
|
<nav></nav>
|
|
</header>
|
|
</body>
|
|
|
|
/ The div tag is the default element, so they can be written simply like this
|
|
.foo
|
|
|
|
/ To add content to a tag, add the text directly after the declaration
|
|
%h1 Headline copy
|
|
|
|
/ To write multiline content, nest it instead
|
|
%p
|
|
This is a lot of content that we could probably split onto two
|
|
separate lines.
|
|
|
|
/
|
|
You can escape html by using the ampersand and equals sign ( &= ). This
|
|
converts html-sensitive characters (&, /, :) into their html encoded
|
|
equivalents. For example
|
|
|
|
%p
|
|
&= "Yes & yes"
|
|
|
|
/ would output 'Yes & yes'
|
|
|
|
/ You can unescape html by using the bang and equals sign ( != )
|
|
%p
|
|
!= "This is how you write a paragraph tag <p></p>"
|
|
|
|
/ which would output 'This is how you write a paragraph tag <p></p>'
|
|
|
|
/ CSS classes can be added to your tags either by chaining .classnames to the tag
|
|
%div.foo.bar
|
|
|
|
/ or as part of a Ruby hash
|
|
%div{:class => 'foo bar'}
|
|
|
|
/ Attributes for any tag can be added in the hash
|
|
%a{:href => '#', :class => 'bar', :title => 'Bar'}
|
|
|
|
/ For boolean attributes assign the value 'true'
|
|
%input{:selected => true}
|
|
|
|
/ To write data-attributes, use the :data key with its value as another hash
|
|
%div{:data => {:attribute => 'foo'}}
|
|
|
|
|
|
/ -------------------------------------------
|
|
/ Inserting Ruby
|
|
/ -------------------------------------------
|
|
|
|
/
|
|
To output a Ruby value as the contents of a tag, use an equals sign followed
|
|
by the Ruby code
|
|
|
|
%h1= book.name
|
|
|
|
%p
|
|
= book.author
|
|
= book.publisher
|
|
|
|
|
|
/ To run some Ruby code without rendering it to the html, use a hyphen instead
|
|
- books = ['book 1', 'book 2', 'book 3']
|
|
|
|
/ Allowing you to do all sorts of awesome, like Ruby blocks
|
|
- books.shuffle.each_with_index do |book, index|
|
|
%h1= book
|
|
|
|
if book do
|
|
%p This is a book
|
|
|
|
/ Adding ordered / unordered list
|
|
%ul
|
|
%li
|
|
=item1
|
|
=item2
|
|
|
|
/
|
|
Again, no need to add the closing tags to the block, even for the Ruby.
|
|
Indentation will take care of that for you.
|
|
|
|
/ -------------------------------------------
|
|
/ Inserting Table with bootstrap classes
|
|
/ -------------------------------------------
|
|
|
|
%table.table.table-hover
|
|
%thead
|
|
%tr
|
|
%th Header 1
|
|
%th Header 2
|
|
|
|
%tr
|
|
%td Value1
|
|
%td value2
|
|
|
|
%tfoot
|
|
%tr
|
|
%td
|
|
Foot value
|
|
|
|
|
|
/ -------------------------------------------
|
|
/ Inline Ruby / Ruby interpolation
|
|
/ -------------------------------------------
|
|
|
|
/ Include a Ruby variable in a line of plain text using #{}
|
|
%p Your highest scoring game is #{best_game}
|
|
|
|
|
|
/ -------------------------------------------
|
|
/ Filters
|
|
/ -------------------------------------------
|
|
|
|
/
|
|
Use the colon to define Haml filters, one example of a filter you can
|
|
use is :javascript, which can be used for writing inline js
|
|
|
|
:javascript
|
|
console.log('This is inline <script>');
|
|
|
|
```
|
|
|
|
## Additional resources
|
|
|
|
- [What is HAML?](http://haml.info/) - A good introduction that does a much better job of explaining the benefits of using HAML.
|
|
- [Official Docs](http://haml.info/docs/yardoc/file.REFERENCE.html) - If you'd like to go a little deeper.
|