updates for new svg view/download links

extras/svg-links.js

@@ -0,0 +1,58 @@
+(() => {
+	
+	if (document.readyState === 'complete') {
+		add_svg_links();
+	}
+
+	else {
+		window.addEventListener('DOMContentLoaded', add_svg_links);
+	}
+
+	function add_svg_links() {
+		const svg_elems = document.querySelectorAll('figure > svg');
+
+		for (const svg_elem of svg_elems) {
+			const figure_elem = svg_elem.parentElement;
+			const anchor_elem = document.createElement('a');
+			const lang = figure_elem.getAttribute('data-lang') || '';
+
+			let svg_html;
+
+			if ('svg_link_css' in window) {
+				const svg_clone = svg_elem.cloneNode(true);
+				const style_elem = document.createElement('style');
+				svg_clone.insertBefore(style_elem, svg_clone.firstChild);
+
+				const css
+					= (window.svg_link_css['*'] || '')
+					+ (lang ? window.svg_link_css[lang] || '' : '');
+	
+				style_elem.setAttribute('type', 'text/css');
+				style_elem.appendChild(document.createTextNode(css));
+
+				svg_html = svg_clone.outerHTML;
+			}
+
+			else {
+				svg_html = svg_elem.outerHTML;
+			}
+			
+			const box = document.createElement('div');
+			const svg_xml = '<?xml version="1.0" standalone="no" ?>\r\n'
+				+ svg_html.replace(/(&(?!(amp|gt|lt|quot|apos))[^;]+;)/g, ($0, $1) => {
+					box.innerHTML = $0;
+					return box.textContent;
+				});
+
+			const svg_blob = new Blob([ svg_xml ], { type: 'image/svg+xml; charset=utf-8' });
+			const svg_object_url = URL.createObjectURL(svg_blob);
+
+			anchor_elem.href = svg_object_url;
+			anchor_elem.className = 'view-svg';
+			anchor_elem.textContent = 'View / Download Graphic';
+
+			figure_elem.insertBefore(anchor_elem, svg_elem);
+		}
+	}
+
+})();