Add Content to Content()

Question

The Question::: This is a strange question but I need to add content to content() in page.php. How do I do this?

The Why::: You see there's a plugin that uses the [plugin id="1337"] and I am linking this id with user ID so the ID needs to be dynamic and then added to the content of the page. This way each user will see something different from the plugin it will be cool I swear.

I tried added it directly to the html but no luck it has to be added to content() somehow. No luck finding anything online either.

Installation::: I'm running wordpress version 3.2.1 and using the TwentyEleven Theme

Answer 1

// Hook into the_content filter here
function append_to_the_content($content){
    ob_start();
    // Start doing stuff here ...

    // End doing stuff here ...
    $new_content = ob_get_clean();
    return $content.$new_content; // Append new content
    return $new_content.$content; // Prepend new content
} // function append_to_the_content($content)
// 11 priority avoid wpautop() that messes custom HTML
add_filter('the_content', 'append_to_the_content', 11);

Regards.