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# Macros in rest2web

## Using Macros

Macros

- About macros
- Where are Macros Defined?
  - The Macros File
- Things you should know
  - The Order
  - Filepaths
  - Modules
- Advanced Macros
- The Example Macros
  - curlyl and curlyr
  - lt
  - smiley
  - acronym
  - emoticon
  - include
  - colorize
  - +/- coloring
  - small
  - name
  - title
- Including Macros in ReST Pages
  - The Raw Role
  - The Raw Directive
  - Paragraphs
- namespace and uservalues
- Credits
- Footnotes

# About macros

Macros allow you to use a shorthand for often-used text or HTML.

As a simple example, let's say that I use a certain link a lot. I don't want to type it over and over again. I can define a macro foo to include this link every time I type `{foo}`:

foo = 'My link'

In this case, the "macro definition" is simply a string that contains the HTML we want to substitute. We can use more sophisticated macros, though.

Let's assume that I use acronyms a lot, and I'm getting tired of having to type that tag again and again. It would be nice if I could type something like `{acronym;IMO;In My Opinion}`

which expands to IMO. (Move your mouse over the "IMO" to see the effect. Not all browsers may support this.)

To achieve this, we define a simple Python function:

def acronym(acronym, meaning):
return '<acronym title="%s">%s</acronym>' % (
meaning, acronym)

{acronym;IMO;In My Opinion} is equivalent to the function call `acronym("IMO", "In My Opinion")`.

These macros can also be used to do more complex things, like insert pictures, include whole files etc.

Note

Macros pass through the ReST processing untouched (unless you include characters that ReStructured text normal escapes, like '<').

This means that macros on a line of their own will be processed as a paragraph. The generated HTML will be between paragraph tags: `<p>...</p>`.

# Where are Macros Defined?

As of rest2web 0.5.0 all the macros described here are built-in to rest2web. That means you can use them without supplying a macros file.

Two of the built in macros require paths to operate properly. You can do this using the config file. See the smiley and emoticon macros.

You can still override these built-in macros, by defining them in your own macros file. Anything in the macros file will override the built in ones.

## The Macros File

In the rest2web config file you can specify a path to a macros module. This can have any name, but it should be a module that Python can import. Basically that means the filename has to end in '.py' [1].

So, to get started, here's what you need to do:

- Create a file called macros.py.
- Add definitions to it. (It helps if you know some Python, of course, but even without that you can enter simple string macros of the form `name = 'text'`.)
- Put the location of this file in the rest2web config file for your site.

# Things you should know

- Macros are string-based. If a macro's return value isn't a string, then it's turned into one (if at all possible).
- Arguments for a function call are strings too; `{foobar;42}` is the function call `foobar("42")`, not `foobar(42)`. If you want a different type, you'll have to explicitly convert in inside your function.
- Functions with no arguments are called by their name: `{baz}` is equivalent to `baz()`, if baz is a callable object. If not, then the value is taken.
- If a macro name isn't found, it is left alone. In fact, this piece of documentation exists as it is because of this rule. Text like `{knarf}` would be replaced' if it was a macro. Since we didn't define a macro knarf, it is left alone and shows up in text with curly braces and all.
- If an error occurs in a macro (function call), it is left alone as well. So are macros containing newlines.
- If you want to include a semicolon (;) or a curly brace in your arguments, you're out of luck. There are currently no ways to do this. You can always define escape sequences in your functions of course.
- Ditto if you want to suppress a macro call that would normally be substituted. other than the `{curlyl}`, and `{curlyr}`, macros. See The Example Macros below.
- Macros map to Python objects. Usually you'll want to use strings or functions, but other objects are possible as well.
- If you define a function you can also give it a shorter name. For example, to give our smiley function the shorter name sm, I included the line `sm = smiley` after the function definition.

## The Order

Macros are resolved after the pages has been processed by docutils [2]. This means your macros should return html for direct inclusion in the final page.

They are resolved before the page is passed to the template engine. This means that dynamic values like `<% path_to_root %>` output by macros will be resolved.

## Filepaths

Before the macros are run, the current directory is changed to be the same as the macros file. This means all file paths supplied to macros should be relative to this file.

## Modules

The modules directory in the rest2web distribution includes various Python modules used by the macros. If you aren't using macros then you don't need this directory. Credits for all the modules here are in the Credits section below.

This directory is put in the Python search path. If you move them elsewhere you should make sure they are on the `sys.path`. If you don't know what I'm on about then leave them where they are

# Advanced Macros

As well as the normal macros discussed above, there is a more advanced system of macros as well. This allows you to apply a macro to a whole chunk of text. Unlike the simple macros, these macros can be nested to apply several effects to passages.

The advanced macros work by enclosing a passage of text between a `{+macro}` and a `{-macro}`. The macro is applied to all the text between the + and the -. In this case it would be applied to and a.

You can also nest them So you can do things like :

    {+second}{+first} The text {-second}{-first}

    {+whole} Some text {+part} a bit in the middle {-part} more text{-whole}

These macros aren't the same as normal macros though. Here's the idea. While a regular macro `{f;x;y}` translates to a function call `f("x", "y")`, the + and - versions use a class definition. A simple example :

class rot13(textmacros.BaseMacro):
def open(self, text):
return text.encode("rot13")

Once this is defined, in your macros file (or just imported into it), you can use it as follows :

    The solution is {+rot13}not for your eyes{-rot13}.

Upon execution, this will convert the text between the rot13 tags. This becomes :

    The solution is abg sbe lbhe rlrf.

In your class the +tag corresponds to the class's `open(text)` method, the -tag to the `close()` method.

Note that if you are using docutils to process your text then it will be processed by docutils before it is processed by the macro. If you want to bypass this, and pass the text to your macro only, then you need to use the `.. raw:: html` directive. e.g. :

    .. raw:: html

        {+rot13}
        this text will *not* be processed as reST
        {-rot13}

# The Example Macros

These are the macros that come built into rest2web.

## curlyl and curlyr

These two macros perform simple substitution. They are a way of including curly left hand brackets and curly right hand brackets in your pages. They are also have the shorter forms `cl` and `cr`.

For example, to include `{example}` in your page - without it being interpreted as a macro - you can write `{curlyl}example{curlyr}` or `{cl}example{cr}`.

This came in very handy when creating this page

## lt

This is another simple substitution macro. It puts a '<' (less than) symbol into pages.

It is especially where you need to include a literal `<$ ... $>` or `<* .. *>` in your pages.

Example :

> `{lt}`

## smiley

This is one of the nicest macros. It uses a modified version of smiley.py by Mark Andrews to put smilies onto your site.

In order to use the smilies, rest2web needs to know the path to the smiley images on your hard drive, and also what URL path you want to be used in the image links that rest2web generates. You do this in the `[Macro Paths]` section of your config file.

The two values to supply are :

- `smiley_directory`

  > The default is to use the standard set which come built in to rest2web.

- `smiley_url`

  > The default is to use the following path, `'<% path_to_root %>images/smilies/'`.

You can use `sm` as a shorter alias for `smiley`.

Examples :

> `{smiley;:-)}` becomes

> `{sm;:roll:}` becomes

It will read standard smiley packages like the ones used by phpbb. Download more from the stylesdb site.

You can see a full list of all of the smilies from the example set in the Smilies Page.

## acronym

We`ve seen this in the first example. `{acronym;acronym;meaning}` produces acronym. You can also use `{acro;acronym;meaning}`.

As an added bonus there are a few standard acronyms that can be called without the acronym definition. These are :

# a dictionary of standard acronyms
# keys should be lowercase
acronyms = {
'wysiwyg' : 'What You See Is What You Get',
'html' : 'HyperText Markup Language',
'xml' : 'eXtensible Markup Language',
'xhtml' : 'eXtensible HyperText Markup Language',
}

So you can do `{acro;WYSIWYG}`, which becomes WYSIWYG . Feel free to add your own of course.

The built in acronyms are :

    {
    'wysiwyg': 'What You See Is What You Get',
    'html': 'HyperText Markup Language',
    'xml': 'eXtensible Markup Language',
    'xhtml': 'eXtensible HyperText Markup Language',
    'rest': 'ReStructuredText',
    'css': 'Cascading Style Sheets',
    'ie': 'Internet Exploder',
    'afaik': 'As Far as I Know',
    'ianal': 'I am not a Lawyer',
    'ssi': 'Server Side Includes',
    'cgi': 'Common Gateway Interface',
    'lol': 'Laughing Out Loud',
    'rotfl': 'Roll On the Floor Laughing',
    'http': 'HyperText Transfer Protocol',
    'ascii': 'American Standard Code for Information Interchange',
    'gui': 'Graphical User Interface',
    'cli': 'Command Line Interface',
    'pda': 'Personal Digital Assistant',
    'rtfm': 'Read the Manual',
    'ftp': 'File Transfer Protocol',
    'nntp': 'Network News Transfer Protocol',
    'uk': 'United Kingdom',
    'pc': 'Personal Computer',
    'url': 'Uniform Resource Locator',
    'uri': 'Uniform Resource Identifier',
    'tcp/ip': 'Transport Control Protocol/Internet Protocol',
    'udp': 'User Data Paragram'
    }

The `macros.py` file that comes with rest2web contains an acronyms dictionary. Any acronyms that you add to this dictionary will be available to the acronyms macro.

## emoticon

This is another shorthand way of including images in your pages. It's useful for putting emoticons inline with text, hence the name. Unlike the `smiley` macro it doesn't need to read anything of disk.

rest2web needs to know what url path to use for the emoticon images. You can supply this using the `emoticon_url` value in the `[Macro Paths]` section of your config file. If you don't supply a value, the default is `'<% path_to_root %>images/'`.

The emoticon macro assumes your images are all 'gif's.

Warning

Including images without specifying a size may slow down the browser rendering of your pages. You could make all your images the same size and hardwire the sizes into the 'img' tag that this macro creates. Alternatively you could do something clever with the PIL by Frederik Lundh - and have it work out the sizes and insert them for you.

Examples :

> `{emoticon;eyeballz}` becomes

> `{emo;noise}` becomes

You can use `emo` as a shorter alias for `emoticon`.

## include

This macro is very simple. Give it a filepath (relative to the macro module) and it will include the contents of that file into this page. The optional 'escape' parameter allows you to escape whitespace. This will insert files as they are - without having to use the '<pre>' tag, which breaks my layout - have I mentioned that before ?

For example `<tt>{include;r2w.ini;True}</tt>` escapes the r2w.ini file and inserts it into the page :

`# Attempt to use psyco ?
psyco = True
# pause after building ?
pause = True
# the root directory
start_directory = 'docs'
# the directory to generate files in
target_directory = 'docs_html'
# directory to compare against (defaults to target_directory)
compare_directory = ''
# file to log output to (if any)
log_file = 'log.txt'
# Skip errors (continue processing)
skiperrors = False
# file containing macros (if any)
macros = 'macros.py'
# Promote lone section headers to title
# rest only and only in the absence of an
# explicit page-title
promote_headers = True
# Enter DEBUG mode ?
# (Interactive interpreter prompt in each page namespace)
DEBUG = False
[uservalues]
# Any global uservalues you want to set
__encoding__ = 'UTF8'
uservalue1 = A Value
uservalue2 = Another Value
[Macro Paths]
smiley_directory = ''
smiley_url = 'images/smilies/'
emoticon_url = 'images/'
`

You can use `inc` as a shorter alias for `include`.

To include HTML files (without escaping), use `{include;some_file.html}`.

## colorize

This macro takes a file and applies Python syntax highlighting to it. You need the right rules in your CSS file for the coloring to be visible. See the rules that start py in `test.css`.

`{colorize;docs/example_function.txt}` becomes :

#
# syntax coloring
try:
import colorize as col
except ImportError:
def colorize(filename):
raise ImportError, 'Importing colorize.py failed.'
else:
def colorize(filename):
"""
format a python script as html
Using the appropriate css it will be nicely colored.
Needs the colorize.py module.
"""
fullname = os.path.join(filename)
f = open(fullname, 'r')
data = f.read()
f.close()
p = col.Parser(data)
p.format(None, None)
src = p.getvalue()
return src.replace('\n', '<br />\n').replace(' ', '&nbsp;&nbsp;')
# to avoid having to use <pre>..

You can use `col` as a shorter alias for `colorize`.

To use the colorize macro, you need the right definitions in your CSS. Something like :

    .pysrc {
        border: #c0c0ff 2px dotted;  padding:10px;
        font-weight: normal; background: #e0e0ff; margin: 20px;
        padding:10px;
    }

    .pykeyword {
        font-weight: bold;
        color: orange;
    }
    .pystring {
        color: green
    }
    .pycomment {
        color: red
    }
    .pynumber {
        color:purple;
    }
    .pyoperator {
        color:purple;
    }
    .pytext {
        color:black;
    }
    .pyerror {
        font-weight: bold;
        color: red;
    }

Change the color definitions to alter the appearance.

## +/- coloring

This is the only example of an advanced macro included. It does the same job as the `colorize` macro, but instead of passing it a filename - it works on the text it encloses. This :

    .. raw:: html

        {+coloring}
        class coloring:
            """A Macro for coloring chunks of text."""
            def open(self, data):
                p = color.Parser(data)
                p.format(None, None)
                src = p.getvalue()
                src = src.replace('\n', '<br />\n')
                return src.replace('  ', '&nbsp;&nbsp;')

            def close(self, *args):
                pass
        {-coloring}

Becomes :

class coloring:
"""A Macro for coloring chunks of text."""
def open(self, data):
p = color.Parser(data)
p.format(None, None)
src = p.getvalue()
return src.replace('\n', '<br />\n').replace(' ', '&nbsp;&nbsp;')
def close(self, *args):
pass

## small

This macro puts the enclosed text between <small>.... </small> tags. This is a feature missing from docutils.

<cl}small;Some text that we would like to make smaller} becomes Some text that we would like to make smaller.

## name

This macro inserts a named anchor tag. This means you can link to the tag using the name you provide.

{name;anchor} would insert the following HTML - `<a name="anchor" id="anchor"></a>`.

You link to it using the HTML - `<a href="#anchor">Link to Anchor</a>`.

## title

This is a shortcut for inserting headlines. You pass in the text and the size (which defaults to an `h3` headline).

{title;A Headline} becomes :

    .. raw:: html

> ### A Headline

{title;Another Headline;1} becomes :

    .. raw:: html

> # Another Headline

# Including Macros in ReST Pages

Macros are just treated as ordinary text by docutils. That means that they must fit into the reST syntax. If they don't, then you should escape them using the raw role or the raw directive.

## The Raw Role

The raw role can only be used if it is declared at the start of the document. You must include the following declaration :

    .. role:: raw-html(raw)
        :format: html

From then on you can pass anything through docutils untouched, like this : `:raw-html:`{small;Something to be made small}``

In the above example it's not very useful. However, macros return HTML. If you tried to include HTML in your macro - docutils would escape the < tags, and they would be included as text (or break your macro).

So `{small;<em>Something to be made small</em>}` doesn't work in reST documents. Try it if you don't believe me.

Instead you can do `:raw-html:`{small;<em>Something to be made small</em>}``, which does work.

## The Raw Directive

If you use the Advanced Macros then you almost certainly want to include a passage of text to transform it. That transformation will be done after docutils has seen the text. Usually you will want the macro to transform your text verbatim - and have docutils leave it alone. In this case you need to use the raw directive.

The classic example of this is the Python source coloring macro :

    .. raw:: html

        {+coloring}

        section = sections['section-name']
        pages = section['pages']

        {-coloring}

If you didn't include the raw directive, docutils would do strange things to the chunk of code - and the macro wouldn't be able to process it.

## Paragraphs

Docutils treats macros as ordinary text. That means if it comes across one on its own it will treat it as a paragraph. That may not be what you intend.

For example - the {title} macro is used to create headlines. If you put this in your document on it's own, then docutils will encase it in paragraph tags. The following :

    {title;Some Heading}

Produces this HTML :

    <p><h3>Some Heading</h3></p>

This is neither valid, nor what you intended. The way round it, is to use the raw directive :

    .. raw:: html

        {title;Some Heading}

# namespace and uservalues

The `macros.py` file that comes with rest2web has a `set_uservalues` function. This is used to set the global values `namespace` and `uservalues`.

That means that you can use access the uservalues and namespace for each page from your macros.

# Credits

The example macro file uses various Python modules. These are included in the `modules` directory that comes with the rest2web distribution. If you don't use the macros, you don't need this folder.

The various modules come from the following people and places :

- A lot of the text in this page comes from the document Firedrop macros by Hans Nowak
- The macros module [3] comes from Firedrop by Hans Nowak
- The smilies use smiley.py by Mark Andrews.
- smiley.py depends on path.py by Jason Orendorff.
- smiley.py uses smiley sets that follow the phpbb convention, you can download alternative sets from stylesdb.
- The smiley set included with rest2web is by a gentleman called Spider.
- The colorize macro uses a module called colorize.py. It originated as part of the MoinMoin project. The version we use is the one from the Python Cookbook.

# Footnotes

[1] | And the filename must only consist of alphanumerics and the underscore character. It should start with a letter, not a number, and is case sensitive, got all that ?

[2] | Assuming the page is in reST format of course.

[3] | textmacros.py - in the rest2web folder.

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Page last modified Thu Oct 12 22:24:09 2006.

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