🔩 mend.html

Mend is a simple HTML template processor designed to, but not limited to be used to generate static websites.

Caution

This project is currently in Beta, meaning that it is NOT production ready.

• Installation
• Usage
  • Example Usage
• Language Specification
  • 1. Comment Statements
    • Extend Statement
    • If Statement
    • Range Statement
    • Include Statement
    • Slot Statement
  • 2. Expression Statements

Installation

Download the latest release or install via the command line with:

go install github.com/bbfh-dev/mend.html

Usage

Run mend --help to display usage information.

Example Usage

mend build -s '{"title":"Hello World!","filename":"index.html","items":[]}' example/index.html > dist/output.html

This command builds the example/index.html file along with all its dependencies into dist/output.html using the provided JSON parameters.

Note that mend build outputs the result into Stdout, which is why > operator is used to redirect output into a file.

Language Specification

Tip

In the documentation, [argument] denotes required arguments and (argument) denotes optional ones.

Mend processes a file's content unchanged until it encounters one of two types of mend statements:

1. Comment Statements

Important

Mend comments must be on separate, single lines to be recognized and processed.

There are two types of comment statements:

• <!-- @... --> — A simple inline mend statement.
• <!-- #... --> paired with <!-- /... --> — A mend block used to wrap a section of content.

Extend Statement

Syntax:
<!-- #extend [filename] (parameters) --> ... <!-- /extend -->

This statement extends a referenced file. Use the Slot statement within the parent file to define where the child content should be inserted.

If Statement

Syntax:
<!-- #if [name] [operator] [value] --> ... <!-- /if -->

This block conditionally removes its enclosed content if the specified condition evaluates to false.

Supported Operators:

• == (equals)
• != (does not equal)
• has (checks if an array contains a specified element)
• lacks (checks if an array does not contain a specified element)

Range Statement

Syntax:
<!-- #range [parameter] --> ... <!-- /range -->

This block iterates over an array. To access properties of the current item, prefix the expression with # (for example, {{ #.child_property }}).

Include Statement

Syntax:
<!-- @include [filename] (parameters) -->

This inline statement inserts the contents of the referenced file directly into the current document.

Slot Statement

Syntax:
<!-- @slot -->

This statement marks the insertion point for content when a file is extended. Note: Each file can declare only one slot.

2. Expression Statements

Expression statements insert values directly into the output.

• An expression beginning with . accesses a property from the input JSON (e.g. {{ .path.to.name }} retrieves the value at path.to.name).
• Using just . outputs the entire JSON object (the root).

Expressions can also include modifiers, using the format: {{ modifier_name .path.to.property }}.

Supported Modifiers:

• length, len, or size — Returns the length of an array.
• quote — Wraps the output value in double quotes.