jojaba

Bonjour,
Eh bien advanced Excerpt est exactement ce dont vous avez besoin.

Translation :
Question

I would like to display excerpt with html format

Answer

Advanced Excerpt is exactly what you need to do that

I just tried to install the plugin into another WordPress site anywhere else. The metabox doesn’t display even for the super admin…
Something wrong with the printing of the metabox?

/**
 * Adds a meta box to the post editing screen
 */
function vsaw_custom_meta() {
	add_meta_box( 'vsaw_meta', __( 'Informations sur l\'évènement', 'vsaw-textdomain' ), 'vsaw_meta_callback', 'event', 'high' );
}
add_action( 'add_meta_boxes', 'vsaw_custom_meta' );

/**
 * Outputs the content of the meta box
 */
function vsaw_meta_callback( $post ) {
	wp_nonce_field( basename( __FILE__ ), 'vsaw_nonce' );
	$vsaw_stored_meta = get_post_meta( $post->ID );
	?>

	<p class="start_date">
		<label for="meta-start-date"><?php _e( 'Début de l\'évènement', 'vsaw-textdomain' )?></label><br>
		<input required type="text" name="meta-start-date" id="meta-start-date" value="<?php if ( isset ( $vsaw_stored_meta['meta-start-date'] ) ) echo $vsaw_stored_meta['meta-start-date'][0]; ?>" />
	</p>

	<p class="end_date">
		<label for="meta-end-date"><?php _e( 'Fin de l\'évènement', 'vsaw-textdomain' )?></label><br>
		<input type="text" name="meta-end-date" id="meta-end-date" value="<?php if ( isset ( $vsaw_stored_meta['meta-end-date'] ) ) echo $vsaw_stored_meta['meta-end-date'][0]; ?>" />
	</p>

	<p class="location">
		<label for="meta-loc"><?php _e( 'Lieu', 'vsaw-textdomain' )?></label><br>
		<input required type="text" name="meta-loc" id="meta-loc" value="<?php if ( isset ( $vsaw_stored_meta['meta-loc'] ) ) echo $vsaw_stored_meta['meta-loc'][0]; ?>" />
	</p>

	<p class="url">
		<label for="meta-url"><?php _e( 'URL (facultatif)', 'vsaw-textdomain' )?></label><br>
		<input type="text" name="meta-url" id="meta-url" value="<?php if ( isset ( $vsaw_stored_meta['meta-url'] ) ) echo $vsaw_stored_meta['meta-url'][0]; ?>" />
	</p>

	<script>
	/* The date picker displaying */
    jQuery(document).ready(function(){
    		jQuery("#meta-start-date, #meta-end-date").on("click", function() {
    				jQuery(this).pickadate();
    		});
    });
    </script> 

	<?php
}

Should I use this function ?
<?php register_post_type( $post_type, $args ) ?>
Found on Function register post type in WordPress Codex – http://codex.wordpress.org/Function_Reference/register_post_type