6.1 Template syntax

6.1.1 Comments

Anything between the sequence $-- and the end of the line will be treated as a comment and omitted from the output.

6.1.2 Delimiters

To mark variables and control structures in the template, either $…$ or ${…} may be used as delimiters. The styles may also be mixed in the same template, but the opening and closing delimiter must match in each case. The opening delimiter may be followed by one or more spaces or tabs, which will be ignored. The closing delimiter may be followed by one or more spaces or tabs, which will be ignored.

To include a literal $ in the document, use $$.

6.1.3 Interpolated variables

A slot for an interpolated variable is a variable name surrounded by matched delimiters. Variable names must begin with a letter and can contain letters, numbers, _, -, and .. The keywords it, if, else, endif, for, sep, and endfor may not be used as variable names. Examples:

$foo$
$foo.bar.baz$
$foo_bar.baz-bim$
$ foo $
${foo}
${foo.bar.baz}
${foo_bar.baz-bim}
${ foo }

Variable names with periods are used to get at structured variable values. So, for example, employee.salary will return the value of the salary field of the object that is the value of the employee field.

6.1.4 Conditionals

A conditional begins with if(variable) (enclosed in matched delimiters) and ends with endif (enclosed in matched delimiters). It may optionally contain an else (enclosed in matched delimiters). The if section is used if variable has a non-empty value, otherwise the else section is used (if present). Examples:

$if(foo)$bar$endif$

$if(foo)$
  $foo$
$endif$

$if(foo)$
part one
$else$
part two
$endif$

${if(foo)}bar${endif}

${if(foo)}
  ${foo}
${endif}

${if(foo)}
${ foo.bar }
${else}
no foo!
${endif}

The keyword elseif may be used to simplify complex nested conditionals:

$if(foo)$
XXX
$elseif(bar)$
YYY
$else$
ZZZ
$endif$

6.1.5 For loops

A for loop begins with for(variable) (enclosed in matched delimiters) and ends with endfor (enclosed in matched delimiters).

Examples:

$for(foo)$$foo$$sep$, $endfor$

$for(foo)$
  - $foo.last$, $foo.first$
$endfor$

${ for(foo.bar) }
  - ${ foo.bar.last }, ${ foo.bar.first }
${ endfor }

$for(mymap)$
$it.name$: $it.office$
$endfor$

You may optionally specify a separator between consecutive values using sep (enclosed in matched delimiters). The material between sep and the endfor is the separator.

${ for(foo) }${ foo }${ sep }, ${ endfor }

Instead of using variable inside the loop, the special anaphoric keyword it may be used.

${ for(foo.bar) }
  - ${ it.last }, ${ it.first }
${ endfor }

6.1.6 Partials

Partials (subtemplates stored in different files) may be included by using the name of the partial, followed by (), for example:

${ styles() }

Partials will be sought in the directory containing the main template. The file name will be assumed to have the same extension as the main template if it lacks an extension. When calling the partial, the full name including file extension can also be used:

${ styles.html() }

(If a partial is not found in the directory of the template and the template path is given as a relative path, it will also be sought in the templates subdirectory of the user data directory.)

Partials may optionally be applied to variables using a colon:

${ date:fancy() }

${ articles:bibentry() }

If articles is an array, this will iterate over its values, applying the partial bibentry() to each one. So the second example above is equivalent to

${ for(articles) }
${ it:bibentry() }
${ endfor }

Note that the anaphoric keyword it must be used when iterating over partials. In the above examples, the bibentry partial should contain it.title (and so on) instead of articles.title.

Final newlines are omitted from included partials.

Partials may include other partials.

A separator between values of an array may be specified in square brackets, immediately after the variable name or partial:

${months[, ]}$

${articles:bibentry()[; ]$

The separator in this case is literal and (unlike with sep in an explicit for loop) cannot contain interpolated variables or other template directives.

6.1.7 Nesting

To ensure that content is “nested,” that is, subsequent lines indented, use the ^ directive:

$item.number$  $^$$item.description$ ($item.price$)

In this example, if item.description has multiple lines, they will all be indented to line up with the first line:

00123  A fine bottle of 18-year old
       Oban whiskey. ($148)

To nest multiple lines to the same level, align them with the ^ directive in the template. For example:

$item.number$  $^$$item.description$ ($item.price$)
               (Available til $item.sellby$.)

will produce

00123  A fine bottle of 18-year old
       Oban whiskey. ($148)
       (Available til March 30, 2020.)

If a variable occurs by itself on a line, preceded by whitespace and not followed by further text or directives on the same line, and the variable’s value contains multiple lines, it will be nested automatically.

6.1.8 Breakable spaces

Normally, spaces in the template itself (as opposed to values of the interpolated variables) are not breakable, but they can be made breakable in part of the template by using the ~ keyword (ended with another ~).

$~$This long line may break if the document is rendered
with a short line length.$~$

6.1.9 Pipes

A pipe transforms the value of a variable or partial. Pipes are specified using a slash (/) between the variable name (or partial) and the pipe name. Example:

$for(name)$
$name/uppercase$
$endfor$

$for(metadata/pairs)$
- $it.key$: $it.value$
$endfor$

$employee:name()/uppercase$

Pipes may be chained:

$for(employees/pairs)$
$it.key/alpha/uppercase$. $it.name$
$endfor$

Some pipes take parameters:

|----------------------|------------|
$for(employee)$
$it.name.first/uppercase/left 20 "| "$$it.name.salary/right 10 " | " " |"$
$endfor$
|----------------------|------------|

Currently the following pipes are predefined: