File Highlight: Fix issue causing the Download button to show up on every code blocks.

Author: Golmote

plugins/file-highlight/prism-file-highlight.js

@@ -65,19 +65,24 @@
 				}
 			};
 
-			if (pre.hasAttribute('data-download-link') && Prism.plugins.toolbar) {
-				Prism.plugins.toolbar.registerButton('download-file', function () {
-					var a = document.createElement('a');
-					a.textContent = pre.getAttribute('data-download-link-label') || 'Download';
-					a.setAttribute('download', '');
-					a.href = src;
-					return a;
-				});
-			}
-
 			xhr.send(null);
 		});
 
+		if (Prism.plugins.toolbar) {
+			Prism.plugins.toolbar.registerButton('download-file', function (env) {
+				var pre = env.element.parentNode;
+				if (!pre || !/pre/i.test(pre.nodeName) || !pre.hasAttribute('data-src') || !pre.hasAttribute('data-download-link')) {
+					return;
+				}
+				var src = pre.getAttribute('data-src');
+				var a = document.createElement('a');
+				a.textContent = pre.getAttribute('data-download-link-label') || 'Download';
+				a.setAttribute('download', '');
+				a.href = src;
+				return a;
+			});
+		}
+
 	};
 
 	document.addEventListener('DOMContentLoaded', self.Prism.fileHighlight);

plugins/file-highlight/prism-file-highlight.min.js

@@ -849,19 +849,24 @@ Prism.languages.js = Prism.languages.javascript;
 				}
 			};
 
-			if (pre.hasAttribute('data-download-link') && Prism.plugins.toolbar) {
-				Prism.plugins.toolbar.registerButton('download-file', function () {
-					var a = document.createElement('a');
-					a.textContent = pre.getAttribute('data-download-link-label') || 'Download';
-					a.setAttribute('download', '');
-					a.href = src;
-					return a;
-				});
-			}
-
 			xhr.send(null);
 		});
 
+		if (Prism.plugins.toolbar) {
+			Prism.plugins.toolbar.registerButton('download-file', function (env) {
+				var pre = env.element.parentNode;
+				if (!pre || !/pre/i.test(pre.nodeName) || !pre.hasAttribute('data-src') || !pre.hasAttribute('data-download-link')) {
+					return;
+				}
+				var src = pre.getAttribute('data-src');
+				var a = document.createElement('a');
+				a.textContent = pre.getAttribute('data-download-link-label') || 'Download';
+				a.setAttribute('download', '');
+				a.href = src;
+				return a;
+			});
+		}
+
 	};
 
 	document.addEventListener('DOMContentLoaded', self.Prism.fileHighlight);