htmlcc is a simple HTML templating engine for C. At compile time, htmlcc transpiles template files into C functions to generate HTML, i.e. templates are statically compiled into C.

Usage

python -m htmlcc input.html > output.c

By default, htmlcc emits C code which prints the generated HTML to standard output. An extensible framework is provided to customise this behaviour via the --emitter flag (see htmlcc/emitter/cgit.py for an example implementation).

Features

htmlcc syntax is based loosely on Jinja, using double curly braces.

The following language features are supported:

{% page page_name %} ... {% endpage %} declares a page function with the C signature void page_name(void) { ... }.
- Page functions can declare arguments using the syntax {% page page_name(char *arg1, int arg2) %}, etc.
- {% block block_name %} ... {% endblock %} is equivalent, but emitters may override this and provide for different behaviour.
{{ expression }} escapes and outputs the given char* expression as HTML text.
- {{ expression|attr }} escapes and outputs the given char* expression as an HTML attribute.
- {{ expression|urlencode }} escapes and outputs the given char* expression as a percent-encoded URL component (not implemented for the stdout emitter).
- {{ expression|%d }}, {{ expression|%ld }} escape and output the given int and long expressions respectively.
{% if expr %} ... {% endif %}, {% while expr %} ... {% endwhile %}, {% for init_expr; cond_expr; loop_expr } ... {% endfor %} generate if/while/for statements respectively.
- {% if expr %} ... {% elif expr %} ... {% else %} ... {% endif %} blocks are supported.
{! ... !} inserts raw C code, e.g. {! foo.bar(); !}.
{# ... #} is a comment, which is not included in the generated template.

Using the default emitter, generated C code is cross-platform, has no dependencies, and requires no memory allocations.

Example

{! char *my_name = "Alice"; !}
{% page hello_world %}
<html>
    <body>Hello world, my name is {{ my_name }}!</body>
</html>
{% endpage %}

The above template transpiles into the following C code:

#include <stdio.h>

void output_variable_as_text(char *variable) { /* escape special characters ... */ }

char *my_name = "Alice";

void hello_world(void) {
    printf("%s", "<html>\n");
    printf("%s", "    <body>Hello world, my name is ");
    output_variable_as_text(my_name);
    printf("%s", "!</body>\n");
    printf("%s", "</html>\n");
}

See examples/helloworld.html for a more complex example making use of variables and control flow.