Display post formats differently on index.php (loop in function)

Question

I'm new to WordPress and I'm hoping to display post formats differently on the home page; sort of like this image:

The problem is that the theme I'm using is very different than other themes I've seen, the loop is in a function.

In my index.php, I have

<?php
            if(have_posts()) :
                while(have_posts()) : the_post();
                    echo cool_post_article_normal_block();
                endwhile;
            endif;
?>

In the function it says:

function cool_post_article_normal_block ($usecategory = false)
{
    add_filter( 'excerpt_length', 'cool_article_excerpt_latest_length', 999 );
    add_filter('excerpt_more', 'cool_article_excerpt_latest_more');
    $timeformat = "<time class='post-date' datetime='" . get_the_time("Y-m-d H:i:s") . "'>" . get_the_time("F j, Y ")  . "</time>";
    $categoryarray = get_the_category();
    $categorytext = '';
    if(!empty($categoryarray))
        $categorytext = "<span class='post-category'><a href='" . get_category_link($categoryarray[0]->term_id) . "' rel='category'>" . $categoryarray[0]->name . "</a></span>";
    $authorurl = get_author_posts_url(get_the_author_meta('ID'));
    $authorname = apply_filters('cool_get_author_name', null);
    $authortext = '<span class="post-author">'. __('By', 'cool_textdomain') . ' <a href="' . $authorurl .'" rel="author">' . $authorname .'</a></span>';
    $firsttext = $authortext;
    if($usecategory) {
        $firsttext = $categorytext;
    }

    $post_class = get_post_class(array('review-list', 'clearfix'), get_the_ID());

    if(is_sticky()) {
        $htmlcontent =
            '<article class="'. implode(' ', $post_class) .'">
               <div class="col-md-6">
                   ' . apply_filters('cool_featured_figure_lazy', null, 'half-post-featured') . '
               </div>
               <div class="col-md-6">
                   <div class="">
                       <header class="content">
                           <h2 class="post-title"><a href="'. get_permalink(get_the_ID()) .'">'. get_the_title() .'</a></h2>
                       </header>
                       <div class="post-meta">
                           ' . $firsttext . '
                           ' . $timeformat .  '
                       </div>
                       <div class="post-excerpt">
                           <p>'.  get_the_excerpt() .'</p>
                       </div>
                   </div>
               </div>
           </article>';
    } else {
        $htmlcontent =
            '<article class="'. implode(' ', $post_class) .'">
           <div class="col-md-5">
               ' . apply_filters('cool_featured_figure_lazy', null, 'half-post-featured') . '
           </div>
           <div class="col-md-7">
               <div class="">
                   <header class="content">
                       <h2 class="post-title"><a href="'. get_permalink(get_the_ID()) .'">'. get_the_title() .'</a></h2>
                   </header>
                   <div class="post-meta">
                       ' . $firsttext . '
                       ' . $timeformat .  '
                   </div>
                   <div class="post-excerpt">
                       <p>'.  get_the_excerpt() .'</p>
                   </div>
               </div>
           </div>
       </article>';
    }

    remove_filter( 'excerpt_length', 'cool_article_excerpt_latest_length');
    remove_filter( 'excerpt_more', 'cool_article_excerpt_latest_more');

    return $htmlcontent;
}

What I understand is that I'm supposed to modify between <article></article> but what I don't know how to do is get the post format conditionally; especially since there is already a sticky conditional-- and I don't know PHP well :(

I'm very new to PHP so I'm unsure how to do this. I have several post formats activated: quote, video, gallery, audio and image.

I'd like the loop to go something like:

if (sticky) {
if (quote)
 show title only
} elseif (video, audio, gallery) {
 show title
 show excerpt
} elseif(image){
 show title
 show featured image
} else {
if (quote) {
 show title only
}elseif (video, audio, gallery){
 show title
 show excerpt
} elseif (image) {
 show title
 show featured image
}

Answer 1

The best way to do this is get the post format and then use the switch statement, like this:

$my_format = get_post_format ();
switch ($my_format) {
    case 'quote': $htmlcontent = ... ; break;
    case 'aside': $htmlcontent = ... ; break;
    and so on
    }

The function that builds up $htmlcontent starts with declaring some building blocks that are used later on (from $timeformat to $firsttext). You can improve on this by setting up larger blocks. The code as it is now, for instance, would already be better if it had blocks like this:

$post-title =      '<header class="content">
                       <h2 class="post-title"><a href="'. get_permalink(get_the_ID()) .'">'. get_the_title() .'</a></h2>
                   </header>';

This code is now duplicated, which is never a good idea.

Answer 2

Looking at your list, you are really only changing the default result for excerpts for the image and quote formats (at the moment), you can remove those using the_excerpt filter...

add_filter('the_excerpt','custom_post_format_excerpt',99);
function custom_post_format_excerpt() {
     $noexcerptformats = array('quote','image');
     if (has_post_format($noexcerptformats)) {$excerpt = '';}
     return $excerpt;
}

It looks like your theme has a custom filter for the thumbnail called cool_featured_figure_lazy with two arguments... you might try something like this to remove the featured image for anything but image post formats (and standard posts):

add_filter('cool_featured_figure_lazy','custom_post_format_thumbnail',99,2);
function custom_post_format_thumbnail($thumbnail,$class) {
    $nothumbnailformats = array('quote','video','audio','gallery');
    if (has_post_format($nothumbnailformats)) {$thumbnail = '';}
    return $thumbnail;
}

If you need to you can change the title similarly, you can use the the_title filter for that... eg.

add_filter('the_title','custom_post_format_title',99);
function custom_post_format_title($title) {
     if (is_sticky()) {$title = 'Featured: '.$title;}
     return $title;
}