Custom template for category WordPress - wordpress

Question

Hello I'm new in WordPress custom templates. Can anybody tell me how I can load a different template for a category.
Here is the index.php file
<?php
/**
* The main template file
*
* No comment for now
*
* #package WordPress
* #subpackage site
* #since site
*/
get_header(); ?>
<?php
$strFr='Featured';
$strFinancial='Financial Reports';
$strResearch='Research';
?>
<div id="page-body" role="main">
<div class="container">
<div class="row">
<div class="col-md-12 col-sm-12 col-xs-12 SearchTop">
<form role="search" method="get" id="searchform" class="searchform" action="<?php echo esc_url( home_url( '/' ) ); ?>">
<div class="input-group">
<div class="input-group-addon"><i class="fa fa-search"></i></div>
<input type="text" value="<?php echo get_search_query(); ?>" name="s" id="s" class="form-control customsearchfiled" placeholder="Search of anything related to Site" />
</div>
</form>
</div><!-- SearchTop -->
<div class="col-md-12 col-sm-12 col-xs-12">
<div class="col-md-12 col-sm-12 col-xs-12 mb20 no-gutter">
<div class="col-md-12 col-sm-12 col-xs-12 no-gutter">
<?php if (have_posts()) : ?>
<?php /* Start the Loop */ ?>
<?php while (have_posts()) : the_post(); ?>
<?php get_template_part('content', get_post_format()); ?>
<?php endwhile; ?>
<?php else : ?>
<article id="post-0" class="post no-results not-found">
<?php if (current_user_can('edit_posts')) :
// Show a different message to a logged-in user who can add posts.
?>
<header class="entry-header">
<h1 class="entry-title mt20"><?php _e('No posts to display', 'twentytwelve'); ?></h1>
</header>
<!--<div class="entry-content">
<p><?php //printf(__('Ready to publish your first post? Get started here.', 'twentytwelve'), admin_url('post-new.php')); ?></p>
</div> .entry-content -->
<?php else :
// Show the default message to everyone else.
?>
<header class="entry-header">
<h1 class="entry-title"><?php _e('Nothing Found', 'twentytwelve'); ?></h1>
</header>
<div class="entry-content">
<p><?php _e('Apologies, but no results were found. Perhaps searching will help find a related post.', 'twentytwelve'); ?></p>
<?php get_search_form(); ?>
</div><!-- .entry-content -->
<?php endif; // end current_user_can() check ?>
</article><!-- #post-0 -->
<?php endif; // end have_posts() check ?>
</div>
</div>
</div>
</div>
</div>
</div>
<?php get_footer(); ?>
As far I know the index file is calling content php file that shows the post layout but don't know how to do this. Tried a lot of things but only get php error. I don't know php syntax much
<?php
/**
* Custom template with better structure than WP default.
*
* Used for both single and index/archive/search.
*
* #package WordPress
* #subpackage site
* #since Site 1.0
*/
# for one post
if (is_single()) {
?>
<article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
<header class="entry-header">
<?php if(function_exists('pf_show_link')){echo pf_show_link();} ?>
<p class="text-center topcategory">
<?php foreach((get_the_category()) as $category) {
echo $category->cat_name . ' ';
}
?>
</p>
<h1 class="entry-title"><?php the_title(); ?></h1>
<p class="postmetadown">By :<span class="bluecolor"><?php the_author(); ?></span> | <span><?php the_date() ?></span></p>
</header>
<div class="entry-content col-md-9 col-sm-9 col-xs-12">
<?php the_content(__('Continue reading <span class="meta-nav">→</span>', 'twentytwelve')); ?>
<?php wp_link_pages(array('before' => '<div class="page-links">' . __('Pages:', 'twentytwelve'), 'after' => '</div>')); ?>
</div>
<div class="col-md-3 col-sm-3 col-xs-12">
<?php get_sidebar(); ?>
</div>
<?php if (comments_open()) : ?>
<!--<div id="disqus_thread"></div>

<script type="text/javascript">
/* * * CONFIGURATION VARIABLES: EDIT BEFORE PASTING INTO YOUR WEBPAGE * * */
var disqus_shortname = 'site'; // required: replace example with your forum shortname
/* * * DON'T EDIT BELOW THIS LINE * * */
(function () {
var dsq = document.createElement('script');
dsq.type =
'text/javascript';
dsq.async = true;
dsq.src = '//' + disqus_shortname + '.disqus.com/embed.js';
(document.getElementsByTagName('head')[0] ||
document.getElementsByTagName('body')
[0]).appendChild(dsq);
})();
</script>
<noscript>Please enable JavaScript to view the <a href="http://disqus.com/? ref_noscript">comments powered
by Disqus.</a></noscript>
comments powered by <span class="logo- disqus">Disqus</span>-->
<?php endif; ?>
<footer class="entry-meta col-md-12">
<?php if ($googlePlusAcc = get_the_author_meta('googleplus')) { ?>
<?php hr_single_entry_meta(); ?>
<?php } else { ?>
<?php twentytwelve_entry_meta(); ?>
<?php } ?>
<?php edit_post_link(__('Edit', 'twentytwelve'), '<span class="edit-link">', '</span>'); ?>
<?php if (is_singular() && get_the_author_meta('description') && is_multi_author()) : // If a user has filled out their description and this is a multi-author blog, show a bio on their entries. ?>
<div class="author-info">
<div class="author-avatar">
<?php
/** This filter is documented in author.php */
$author_bio_avatar_size = apply_filters('twentytwelve_author_bio_avatar_size', 68);
echo get_avatar(get_the_author_meta('user_email'), $author_bio_avatar_size);
?>
</div>
<!-- .author-avatar -->
<div class="author-description">
<h2><?php printf(__('About %s', 'twentytwelve'), get_the_author()); ?></h2>
<p><?php the_author_meta('description'); ?></p>
<div class="author-link">
<a href="<?php echo esc_url(get_author_posts_url(get_the_author_meta('ID'))); ?>"
rel="author">
<?php printf(__('View all posts by %s <span class="meta-nav">→</span>', 'twentytwelve'), get_the_author()); ?>
</a>
</div>
</div>
</div>
<?php endif; ?>
</footer>
</article>
<?php
#for listing page
} else {
$category = get_the_category();
if (!empty($category))
$category = $category[0];
?>
<article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
<?php //if (is_sticky() && is_home() && !is_paged()) : ?>
<!--<div class="featured-post">
<?php //_e('Featured post', 'twentytwelve'); ?>
</div>-->
<?php //endif; ?>
<div class="col-md-4 col-sm-4 col-xs-12 categoryimg no-gutter">
<?php if (has_post_thumbnail()) { ?>
<div class="post-thumbnal-wrapper-multiple">
<?php the_post_thumbnail(); ?>
</div>
<?php } ?>
</div>
<div class="col-md-8 col-sm-8 col-xs-12 categoryContent">
<header class="entry-header">
<h1 class="entry-title">
<?php the_title(); ?>
</h1>
</header>
<?php if (is_search()) : // Only display Excerpts for Search ?>
<div class="entry-summary">
<?php the_excerpt(); ?>
</div>
<?php else : ?>
<div class="entry-content">
<?php the_excerpt_more(); ?>
</div>
<?php endif; ?>
<div class="col-md-12">
<footer class="entry-meta">
<?php twentytwelve_entry_meta(); ?>
<?php edit_post_link(__('Edit', 'twentytwelve'), '<span class="edit-link">', '</span>'); ?>
</footer>
</div>
</div><!-- categoryContent -->
</article>
<div class="clearfix"></div>
<?php
}

Answer 1

If you want a template for the category page, see https://codex.wordpress.org/Category_Templates. If you want a different template for the content, based on the category, you could use (in your content.php)
<?php if (is_category('Category A')) : ?>
<p>This is the text to describe category A</p>
<?php elseif (is_category('Category B')) : ?>
<p>This is the text to describe category B</p>
<?php else : ?>
<p>This is some generic text to describe all other category pages,
I could be left blank</p>
<?php endif; ?>
If there's a lot of difference between categories, I would place this in index.php, and create different templates for every category

Answer 2

Check out this page Template Hierachy. Basically if you want to target a specific category you create a file like so category-{slug}.php {slug} being the category slug you want to target.

Answer 3

I suggest you to read about Wordpress Template Hierarchy in https://developer.wordpress.org/themes/basics/template-hierarchy/
To answer your question, you need to create a category-{id}.php or category-{slug}.php file. in your theme folder (Choose only one)
id = your category ID
slug = your category slug
After creating the file, then you can put your custom code if you want.

Answer 4

Add your code inside archive.php which will list all the posts in the category and add the detail page template inside single.php .
https://codex.wordpress.org/Category_Templates