Front end page submission form does not attach custom post type

Question

This side of WordPress is completely new to me, but is also extremely important. I have created a form that allows me to upload a page, with all the parameters I need, however a custom taxonomy is not assigned to the page. However, I need a drop down of all the terms in my custom taxonomy 'walls', so that the user can pick the term and it is assigned to the post. I have googled and searched on stack exchange and yet none of the code examples I found have worked out for me. I have tried the code with categories and it works fine.

Code:

<?php if ( is_user_logged_in() ) { ?>

<?php
$postTitleError = '';

if(isset($_POST['submitted']) && isset($_POST['post_nonce_field']) && wp_verify_nonce($_POST['post_nonce_field'], 'post_nonce')) {

if(trim($_POST['postTitle']) === '') {
$postTitleError = 'Please enter a title.';
$hasError = true;
} else {
$postTitle = trim($_POST['postTitle']);
}

$post_information = array(
'post_title' => esc_attr(strip_tags($_POST['postTitle'])),
'post_content' => esc_attr(strip_tags($_POST['postContent'])),
'post_type' => 'page',
'page_template'  => 'Review.php',
'post_status' => 'pending',
'tax_input' => array( 'walls' => array( $_POST['pickWall'] ) ),
);

$post_id = wp_insert_post($post_information);

if($post_id)
{
// Update Custom Meta
update_post_meta($post_id, 'product_aesthetics', esc_attr(strip_tags($_POST['product_aesthetics_meta'])));

wp_redirect(home_url());
exit;
}

}

?>

<?php get_header(); ?>


<!-- #primary BEGIN -->
<div id="primary">

<form action="" id="primaryPostForm" method="POST">

<fieldset>

<label for="postTitle"><?php _e('Post\'s Title:', 'framework') ?></label>

<input type="text" name="postTitle" id="postTitle" value="<?php if(isset($_POST['postTitle'])) echo $_POST['postTitle'];?>" class="required" />

</fieldset>

<?php if($postTitleError != '') { ?>
<span class="error"><?php echo $postTitleError; ?></span>
<div class="clearfix"></div>
<?php } ?>

<fieldset>

<label for="postContent"><?php _e('Post\'s Content:', 'framework') ?></label>

<textarea name="postContent" id="postContent" rows="8" cols="30"><?php if(isset($_POST['postContent'])) { if(function_exists('stripslashes')) { echo stripslashes($_POST['postContent']); } else { echo $_POST['postContent']; } } ?></textarea>

</fieldset>


<fieldset>

<label for="product_aesthetics_meta"><?php _e('Product Aesthetics Meta:', 'framework') ?></label>

<textarea name="product_aesthetics_meta" id="product_aesthetics_meta" rows="8" cols="30"><?php if(isset($_POST['product_aesthetics_meta'])) { if(function_exists('stripslashes')) { echo stripslashes($_POST['product_aesthetics_meta']); } else { echo $_POST['product_aesthetics_meta']; } } ?></textarea>

</fieldset>

<fieldset>
<label for="pickWall">Type of wall</label> 
<select name="pickWall">

<?php

// ======= Custom post types category drop down ======== 
$taxonomy = 'walls';
$terms = get_terms($taxonomy); // Get all terms of a taxonomy

if ( $terms && !is_wp_error( $terms ) ) :

foreach ( $terms as $term ) { 
echo '<option value="' . get_term_link($term->slug, $taxonomy) . '">' . $term->name . '</option>';
}

endif;
?>

</select>
</fieldset>


<fieldset>

<?php wp_nonce_field('post_nonce', 'post_nonce_field'); ?>

<input type="hidden" name="submitted" id="submitted" value="true" />
<button type="submit"><?php _e('Add Post', 'framework') ?></button>

</fieldset>

</form>

</div><!-- #primary END -->

<?php } ?>

Answer 1

First, you should change your input field names to something unique. category is a WordPress query var, so submitting a form with that field name may have unexpected results.

That said, post_category is only for the category taxonomy, custom taxonomies should use the tax_input parameter.

however... if this form is being submitted by users who are not logged in or don't have the capability to assign terms in your custom taxonomy, then you must use wp_set_object_terms to assign terms after the post is inserted. See the note in wp_insert_post:

'tax_input': Equivalent to calling wp_set_post_terms() for each custom taxonomy in the array. If the current user doesn't have the capability to work a taxonomy, the you must use wp_set_object_terms() instead.

EDIT-

for the select field, you can output the term ID as the option value:

<?php

// ======= Custom post types category drop down ======== 
$taxonomy = 'walls';
$terms = get_terms($taxonomy); // Get all terms of a taxonomy

if ( $terms && !is_wp_error( $terms ) ) :

foreach ( $terms as $term ) { 
    echo '<option value="' . $term->term_id . '">' . $term->name . '</option>';
}

endif;
?>

Then when you insert the post:

'tax_input' => array( 'walls' => array( $_POST['your_tax_field'] ) )