How to have random posts only on index page (not category, author…)?

[ Moderator note: bbcode removed. It doesn’t work in these forums. ]

At first, thanks for great theme ??

I’m working on an interesting online image-dictionary project ([url]https://phut59.com[/url]), and I want to have random word on the index page. After a few searches I did it by adding a php code in function bfa_loop() in template_tags.php to query random posts.

function bfa_loop( $postformat = 'postformat' ) {

	query_posts($query_string . '&orderby=rand'); <!-- here is the code i added -->

	if( have_posts() ) : ?>

	<div class="post-list">
	<?php while (have_posts()) : the_post(); ?>
		<?php bfa_get_template_part( $postformat, get_post_format() ); ?>
	<?php endwhile; ?>
	</div>
...

And it worked, I have random posts on the index page, but it does also to the category and author page too. After that, I figured out the category and author page use the same main template index.php. So I guess that to have normal posts in category (or author page) I must create a new main template “category.php” then make a another loop function like this in template_tags.php

function bfa_loop_norandom( $postformat = 'postformat' ) {

	if( have_posts() ) : ?>

	<div class="post-list">
	<?php while (have_posts()) : the_post(); ?>
		<?php bfa_get_template_part( $postformat, get_post_format() ); ?>
	<?php endwhile; ?>
	</div>
...

Then call it in the category.php main template.

<!--<div id="container">-->
<?php get_header(); ?>
<div id="main" class="row">
	<div id="content" class="cf col8">

    <?php bfa_loop_norandom( 'postformat' );  ?>

	</div>

	<div id="widgetarea-one" class="col4">
		<?php dynamic_sidebar( 'Widget Area ONE' ); ?>
	</div>

</div>
<?php get_footer(); ?>

<!--</div>-->

[You need to use the code buttons right above the posting box – not make your own – your code may have been damaged as is]

But it did not work, there was nothing on category page (for example https://phut59.com/category/tu-sieu-de/) . It seemed the new function I added not work.

I wonder if someone can help.

Thanks in advance ??