Include HTML with conditions?

Question

HTML

Given: there is a footer, it has a block that is different on different pages, block A, block B, block C.
The footer is a separate file that is connected using include.

<include src="source/html-blocks/block_footer.html"></include>

Can I somehow embed blocks with conditions inside the footer? How?
For example, on the main page inside the footer there should be block A, on catalog pages block B, on all other pages block C.
Use gulp and posthtml-include
task:

gulp.task("html", function () {
  return gulp.src("source/*.html")
    .pipe(posthtml([
      include()
    ]))
    .pipe(gulp.dest("build"));
});

Answer 1

Use full-fledged template engines, not any surrogates.
For example twig (gulp-twig for layout)

{% if some_variable == 2 %}
  {% include "file1.twig" %}
{% else %}
  {% include "file2.twig" %}
{% endif %}

UPD
Read the comments. Twig is what is called like html template engine. Those. a normal html file fed to a template engine will not cause compilation errors. This means that you can essentially just insert template engine control constructs into your html.

Answer 2

To make it easier to manage chunks of HTML, use includeHTML .