Templito

The Back end Templating language behind the Siter - a static website generator.

What makes templito different

Templito templates largely resemble those of handlebars and Go templates, but they have a few standout features.

• Language
  • Multiple parameters to templates
  • Functions can be run on the result of a block
  • Whitespace can be escaped
• Rust
  • Template functions can be closures, so they can have data attached to the functions.
  • Template and Function Managers are separate from the template and can be switched in and out generically.

Examples

Basic structure of a template

{{let title = "Page"}}\
<h1>{{first $title "Default Title"}}</h1>
{{if .cat}}\
    {{for k v in .cat}}\
        <p>{{$k}} = {{$v}}</p>
    {{/for}}\
{{/if}}\

Using Blocks

{{@md}}
Markdown
============================

Everthing between an '@<func>' and '\func' tags will run the function on the result of the contents.

for example the because this code is within an '@md' block, the contents will be treated as markdown.

(Assuming the md function is included by the FuncManager)

Ranges like this will create a bullet point list of items:

{{for k v in .items}}
* {{$v}} 
{{- /for}}

{{/md}}

In fact any string to string function can be used as an "@block"

But they are more powerful than that.

{{@let lines}}
apple
cat
sandwhich
{{/let}}\
{{for k v in split $lines}}
    <p>{{$v}}</p>
{{/for}}

will output:

    <p>apple</p>
    <p>cat</p>
    <p>sandwhich</p>

Depending on the security situation, you can opt in or out to allowing "exec" functions. ("exec" is not included in the defaults)

{{for k v in split (exec "cat" "path/to/file") "\n"}}
    <p>{{$k}} = {{$v}}</p>
{{/for}}

Control Flow

• "let"

  Create variables (Used in rest of docs) {{let x=3;y=9;list=["fish","dog"]}}

• "export"

  Export variables can be returned to the calling program in a map of exports

• "if","elif" and "else"

  Control flow, only resolve the contents if the contition is met otherwise look at the elif and elses {{if gt $x 3}}{{$x}}{{elif gt $y 3}}{{$y}}{{else}}Something else{{/if}} //output: 9

• "return"

  return a value instead of the main string

• "for"

  Loop over a list or value. This requires the index, and value be named (eg k and v) {{for k v in $list}}list at {{$k}} equals {{$v}};{{/for}}

  //output: list at 0 equals fish;list at 1 equals dog;

• "switch" and "case"

  choose one option based on the value matched by a pattern {{- switch $list -}} {{- case [_,]}}List with second element {{$b}} {{- case {fish:} }}Map with fish element {{$f}} {{- /switch -}} //output: List with second element dog

• "as"

  Create a single switch case

  {{as $list: [_,]}}{{$b}}{{/as}} //output: dog

• "define" and "global"

  Create functions either as variables to run or globals that are added to the func manager {{define cat age}}I'm a cat aged {{$age}}{/define}} {{run $cat 55}} //output: I'm a cat aged 55

• "@let" and "@export"

  Create a local or exported variable from the contents of the block; {{- @let a -}} I love {{for k v in $list}}{{if eq $k 0}} and {{/if}}{{$v}}{{/for}} {{- /let -}} {{$a}} //output: I love fish and dog