diff --git a/runtime/app.js b/runtime/app.js
index 64cc60b..26dafe1 100644
--- a/runtime/app.js
+++ b/runtime/app.js
@@ -4,6 +4,16 @@ const detach = node => {
let component;
+const scroll_history = {};
+let uid = 1;
+let cid;
+
+window.scroll_history = scroll_history;
+
+if ('scrollRestoration' in history) {
+ history.scrollRestoration = 'manual'
+}
+
const app = {
init(target, routes) {
function select_route(url) {
@@ -22,7 +32,7 @@ const app = {
}
}
- function render(Component, data) {
+ function render(Component, data, scroll) {
Promise.resolve(
Component.preload ? Component.preload(data) : {}
).then(preloaded => {
@@ -48,33 +58,70 @@ const app = {
data: Object.assign(data, preloaded),
hydrate: !!component
});
+
+ window.scrollTo(scroll.x, scroll.y);
});
}
- function navigate(url) {
+ function navigate(url, id) {
const selected = select_route(url);
if (selected) {
+ if (id) {
+ // popstate or initial navigation
+ cid = id;
+ } else {
+ // clicked on a link. preserve scroll state
+ scroll_history[cid] = scroll_state();
+
+ id = cid = ++uid;
+ scroll_history[cid] = { x: 0, y: 0 };
+
+ history.pushState({ id }, '', url.href);
+ event.preventDefault();
+ }
+
selected.route.load().then(mod => {
- render(mod.default, selected.data);
+ render(mod.default, selected.data, scroll_history[id]);
});
+ cid = id;
return true;
}
}
function findAnchor(node) {
- while (node && node.nodeName !== 'A') node = node.parentNode;
+ while (node && node.nodeName.toUpperCase() !== 'A') node = node.parentNode; // SVG elements have a lowercase name
return node;
}
window.addEventListener('click', event => {
+ // Adapted from https://github.com/visionmedia/page.js
+ // MIT license https://github.com/visionmedia/page.js#license
+ if (which(event) !== 1) return;
+ if (event.metaKey || event.ctrlKey || event.shiftKey) return;
+ if (event.defaultPrevented) return;
+
const a = findAnchor(event.target);
if (!a) return;
- if (navigate(new URL(a.href))) {
- event.preventDefault();
- history.pushState({}, '', a.href);
- }
+ event.preventDefault();
+
+ // check if link is inside an svg
+ // in this case, both href and target are always inside an object
+ const svg = typeof a.href === 'object' && a.href.constructor.name === 'SVGAnimatedString';
+ const href = svg ? a.href.baseVal : a.href;
+
+ // Ignore if tag has
+ // 1. 'download' attribute
+ // 2. rel='external' attribute
+ if (a.hasAttribute('download') || a.getAttribute('rel') === 'external') return;
+
+ // Ignore if has a target
+ if (svg ? a.target.baseVal : a.target) return;
+
+ const scroll = scroll_state();
+
+ navigate(new URL(a.href), null);
});
function preload(event) {
@@ -94,11 +141,31 @@ const app = {
window.addEventListener('mouseover', preload);
window.addEventListener('popstate', event => {
- navigate(new URL(window.location));
+ if (!event.state) return; // hashchange, or otherwise outside sapper's control
+ scroll_history[cid] = scroll_state();
+
+ console.log(`storing current scroll: ${cid}`, scroll_state());
+ console.log(`navigating to state: ${event.state.id}`, scroll_history[event.state.id]);
+ navigate(new URL(window.location), event.state.id);
});
- navigate(new URL(window.location));
+ const scroll = scroll_history[uid] = scroll_state();
+
+ history.replaceState({ id: uid }, '', window.location.href);
+ navigate(new URL(window.location), uid);
}
};
+function which(event) {
+ event = event || window.event;
+ return event.which === null ? event.button : event.which;
+}
+
+function scroll_state() {
+ return {
+ x: window.scrollX,
+ y: window.scrollY
+ };
+}
+
export default app;
\ No newline at end of file