I can't find the rights arguments to display only one post of a category when I click on a div. I call the post with Ajax and I display it in a div popup.Perhaps these arguments are not sufficient, or the problem come from another part?But when I echo the get_the_id in the loop it is the correct id of the post.However, it displays all posts in category. Another problem, if I don't specify a category (name or id) it display all posts of my Wordpress.These two problems come only when I call posts in Ajax.

function more_content() {

    $the_post_id = the_ID(); // $_POST['the_ID'];
    $args = array(
        'post_type' => 'post',
        'category_name' => 'materials',
        'p' => $the_post_id

    );

    $ajax_query = new WP_Query($args);
    $the_excerpt;
    $the_content;

    if ( $ajax_query->have_posts() ) : while ( $ajax_query->have_posts() ) : $ajax_query->the_post();

          $the_excerpt = the_excerpt();
          $the_content = the_content();

    endwhile;
    endif; 
    echo $the_excerpt;
  echo "<div style='color:white; font-size:40px;'>",$the_post_id,"</div>";
    echo $the_content;

    wp_reset_postdata();

    die();
}

I can't find the rights arguments to display only one post of a category when I click on a div. I call the post with Ajax and I display it in a div popup.Perhaps these arguments are not sufficient, or the problem come from another part?But when I echo the get_the_id in the loop it is the correct id of the post.However, it displays all posts in category. Another problem, if I don't specify a category (name or id) it display all posts of my Wordpress.These two problems come only when I call posts in Ajax.

function more_content() {

    $the_post_id = the_ID(); // $_POST['the_ID'];
    $args = array(
        'post_type' => 'post',
        'category_name' => 'materials',
        'p' => $the_post_id

    );

    $ajax_query = new WP_Query($args);
    $the_excerpt;
    $the_content;

    if ( $ajax_query->have_posts() ) : while ( $ajax_query->have_posts() ) : $ajax_query->the_post();

          $the_excerpt = the_excerpt();
          $the_content = the_content();

    endwhile;
    endif; 
    echo $the_excerpt;
  echo "<div style='color:white; font-size:40px;'>",$the_post_id,"</div>";
    echo $the_content;

    wp_reset_postdata();

    die();
}

• posts
• wp-query
• parameter

• Is the category a subcategory (or child category)? If so, see developer.wordpress/reference/functions/query_posts/… – Ted Stresen-Reuter Commented Sep 4, 2019 at 10:21
• it's a category (not a subcategory, not a child category). I think the main problem doesn't come with the category, even if it's not normal to define a category to display a unique post. the code above is the functions.php file. Do you think the problem could come from other file ex : ajaxcall.js ? – Rak Arthus Commented Sep 4, 2019 at 10:40

1 Answer 1

I am pretty sure that the Category parameters cannot be combined with p. In the documentation it says: "Show posts associated with certain categories." and none of the examples combine a category with a single post like you are trying to do.

Instead I think you need to use a taxonomy query as such:

$args = [
    'post_type' => 'post', 
    'p'=>(int)$_POST['the_ID'], 
    'tax_query' => [
        [
            'taxonomy'=>'category',
            'field'=>'slug',
            'terms'=>'materials'
        ]
    ]
];

Give that a try and remember to mark this as the answer if it solves your problem.

Also, be sure you are getting the right ID. In the code sample you provided, the_ID() is definitely not what you want. the_ID() echos the value of the ID to the output. What you probably want instead is get_the_ID() but even that will be wrong in this context (retrieving a single post by ID as defined by the input coming from the GET request).

And also, if you are plucking the ID from $_POST or $_GET, be sure to sanitize it prior to using it in your query (although, I'm pretty sure WordPress also sanitizes input prior to running the query, you can never be too safe).