Specifically, I'd like to create a plugin to echo the following in the header immediately after the default stylesheet
The preferred way is to enqueue it, with the default/main stylesheet as the dependency.
Here's a demo plugin, with the structure:
+ plugins/
|
+--+ my-ie-style/
|
+--+ my-ie-style.php
|
+--+ css/
|
+--+ ie.css
where the my-ie-style.php file is:
<?php
/**
* Plugin Name: Demo - My IE style
* Plugin URI: http://wordpress.stackexchange.com/a/85496/26350
* Description: Enqueue With IE conditional, depending on the main-style stylesheet
* Author: wpse
* Version: 1.0.0
*/
add_action( 'wp_enqueue_scripts', function()
{
// Register
wp_register_style(
'my-ie-style', // handle
plugin_dir_url( __FILE__ ) . 'css/ie.css', // file
[ 'main-style' ], // dependency <-- ADJUST THIS!
'1.0.0', // version
'all' // media
);
// Enqueue
wp_enqueue_style( 'my-ie-style' );
// Add IE conditional
wp_style_add_data(
'my-ie-style', // handle
'conditional', // key ('conditional', 'rtl', 'suffix', 'after', 'alt', 'title')
'IE' // value
);
} );
This will generate the following within the <head> tag:
<link rel='stylesheet'
id='main-style-css'
href='http://example.tld/wp-content/themes/mytheme/style.css?ver=4.5.3'
type='text/css'
media='all' />
<!--[if IE]>
<link rel='stylesheet'
id='my-ie-style-css'
href='http://example.tld/wp-content/plugins/my-ie-style/css/ie.css?ver=1.0.0'
type='text/css'
media='all' />
<![endif]-->
where our custom IE stylesheet loads after the main stylesheet.
Hopefully you can adjust it to your needs.