Replace Shortcodes with HTML in Wordpress - php

Question

I'm working on a WordPress site that has been using a plugin to grab amazon product images using a shortcode.
You simply insert the asin of a book into a shortcode, like this:
[amazon template=image&asin=B00FYY53B8]
When the post loads, the shortcode is converted into the actual image HTML using the URL from amazon.... so the example above would return
http://ecx.images-amazon.com/images/I/71kIifYTccL._SL1500_.jpg
I'm using another custom plugin to build out the content for posts, and so far am just using this shortcode as part of the post content. I would like to do some other things, such as set the featured image, etc. and need that URL.
I've tried
echo do_shortcode( '[amazon template=image&asin=B00FYY53B8]' );
But it doesn't return anything. Is there a way to "execute" shortcodes in a plugin and save the output?
Ultimately, I would also like to scale this functionality so I can replace other/old shortcodes with their HTML output, and save it back to the post, essentially eliminating the use of some shortcodes in posts.

Answer 1

I have a demo for add a short code in wordpress. I hope it help.
add_action('plugins_loaded','MOD_load');
function MOD_load() {
short_enable_form();
}
function short_enable_form(){
if(!function_exists('add_shortcode')) {
return;
}
add_shortcode('form_mod' , array(&$this, 'out_put_form'));
}
public function out_put_form(){
return 'HTML TEXT';
}

Answer 2

You can include this code in functions.php. And call this function in content-singular.php or the similar file in your theme.
function updatesc_database( $post ) {
if ( empty($post) ) global $post;
if ( empty($post) || ! isset($post->post_content) ) return false;
$content = $post->post_content;
$shortc1="amazon template=image&asin";
$shortc2="B00FYY53B8]"; //insert the number variable here
$shortwh=$shortc1.$shortc2;
$replace = do_shortcode($shortwh);
$content = str_replace( $shortwh, $replace, $content );
return $content;
}