pub fn fill_placeholders(
blocks: &mut [EmailGutenbergBlock],
replacements: &HashMap<String, String>,
) -> BTreeSet<String>Expand description
Replaces {{KEY}} in every attribute, nested blocks included. Values are HTML-escaped in rich
text and inserted as is elsewhere; a protocol Gutenberg prepended to a link whose whole target is
a placeholder is dropped. Returns the keys found that replacements has no value for;
those are left in place.