Majavat

A templating engine for Clojure

Installation

Add majavat to dependency list

[org.clojars.jj/majavat "1.0.6"]

Usage

Rendering templates

(:require
  [jj.majavat :as majavat])

(majavat/render-file "index.html" {:user "jj"})

Additional options can be passed with

(majavat/render-file "index.html" {:user "jj"} {:return-type :input-stream})

All supported options:

Option	Default Value	Supported Options
return-type	:string	:string, :input-stream
template-resolver	ResourceResolver	Any TemplateResolver implementation
cache?	true	true, false
character-escaper	nil	Any CharEscaper implementation

Creating templates

Inserting value

Rendering file.txt with content

Hello {{ name }}!

(render-file "file.txt" {:name "world"}) ;; => returns Hello world!

or with a filter

Hello {{ name | upper-case }}!

(render-file "file.txt" {:name "world"}) ;; => returns Hello WORLD!

supported filters	type
upper-case	String
lower-case	String
capitalize	String
name	keyword
inc	Number
dec	Number

Conditionals

Rendering input file with content:

"Hello {% if name %}{{name}}{% else %}world{% endif %}!"

(render-file "input-file" {:name "jj"}) ;; returns "Hello jj!"
(render-file "input-file" {}) ;; returns "Hello world!"

or

"Hello {% if not name %}world{% else %}jj{% endif %}!"

(render-file "input-file" {:name "foo"}) ;; returns "Hello jj!"
(render-file "input-file" {}) ;; returns "Hello world!"

Looping

Rendering input file with content:

{% for item in items %}
- {{ item }} is {{ loop.index }} of {{ loop.total }}
{% endfor %}

(render-file "input-file" {:items ["Apple" "Banana" "Orange"]}) ;; returns "- Apple is 0 of 3\n- Banana is 1 of 3\n- Orange is 2 of 3"

The loop context provides access to:

loop.total - total number of items in the collection

loop.index - current 0-based index position

loop.first? - true only for the first item

loop.last? - true only for the last item

Including template

file.txt content

foo

Rendering input file with content:

included {% include "file.txt" %}

(render-file "input-file" {}) ;; returns "included foo"

Setting value

You can set value within a template via:

hello {% let foo = "baz" %}{{ foo }}{% endlet %}

(render-file "input-file" {}) ;; returns "hello baz"

Extending template

file.txt content

foo
{% block content %}
baz

Rendering input file with content:

{% extends content "file.txt" %}
bar

(render-file "input-file" {}) ;; returns "foo\nbar\nbaz"

TemplateResolver

The TemplateResolver protocol provides a uniform interface for accessing template content from different sources.

Protocol Methods

open-reader

Returns reader for that template, or nil if not found.

(open-reader "/templates/header.html")

template-exists?

Check if template exists at a path.

(template-exists? resolver "/templates/footer.html") ;; => true

Built-in Implementations

• ResourceResolver (default) - Reads from classpath
• FsResolver - Reads from filesystem

License

Copyright © 2025 ruroru

This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which is available at https://www.eclipse.org/legal/epl-2.0/.

This Source Code may also be made available under the following Secondary Licenses when the conditions for such availability set forth in the Eclipse Public License, v. 2.0 are satisfied GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version, with the GNU Classpath Exception which is available at https://www.gnu.org/software/classpath/license.html.