Merge pull request #3579 from tcrowe/set-attribute-only-if-different

Rich-Harris · web-flow · commit 99911c31f547 · 2019-10-16T22:05:47.000-04:00
Prevent image flicker and reloading by checking attribute before setting it
diff --git a/src/runtime/internal/dom.ts b/src/runtime/internal/dom.ts
@@ -86,7 +86,7 @@ export function self(fn) {
 
 export function attr(node: Element, attribute: string, value?: string) {
 	if (value == null) node.removeAttribute(attribute);
-	else node.setAttribute(attribute, value);
+	else if (node.getAttribute(attribute) !== value) node.setAttribute(attribute, value);
 }
 
 export function set_attributes(node: Element & ElementCSSInlineStyle, attributes: { [x: string]: string }) {

Original file line number	Diff line number	Diff line change
`@@ -86,7 +86,7 @@ export function self(fn) {`
`86`	`86`
`87`	`87`	`export function attr(node: Element, attribute: string, value?: string) {`
`88`	`88`	`if (value == null) node.removeAttribute(attribute);`
`89`		`- else node.setAttribute(attribute, value);`
	`89`	`+ else if (node.getAttribute(attribute) !== value) node.setAttribute(attribute, value);`
`90`	`90`	`}`
`91`	`91`
`92`	`92`	`export function set_attributes(node: Element & ElementCSSInlineStyle, attributes: { [x: string]: string }) {`