Merge pull request #1715 from sveltejs/dynamic-import

support dynamic import in expressions

src/parse/read/expression.ts

@@ -34,6 +34,9 @@ export default function readExpression(parser: Parser) {
 		const node = parseExpressionAt(parser.template, parser.index, {
 			ecmaVersion: 9,
 			preserveParens: true,
+			plugins: {
+				dynamicImport: true
+			}
 		});
 		parser.index = node.end;
 

test/js/samples/dynamic-import/expected-bundle.js

@@ -0,0 +1,186 @@
+function noop() {}
+
+function assign(tar, src) {
+	for (var k in src) tar[k] = src[k];
+	return tar;
+}
+
+function blankObject() {
+	return Object.create(null);
+}
+
+function destroy(detach) {
+	this.destroy = noop;
+	this.fire('destroy');
+	this.set = noop;
+
+	this._fragment.d(detach !== false);
+	this._fragment = null;
+	this._state = {};
+}
+
+function _differs(a, b) {
+	return a != a ? b == b : a !== b || ((a && typeof a === 'object') || typeof a === 'function');
+}
+
+function fire(eventName, data) {
+	var handlers =
+		eventName in this._handlers && this._handlers[eventName].slice();
+	if (!handlers) return;
+
+	for (var i = 0; i < handlers.length; i += 1) {
+		var handler = handlers[i];
+
+		if (!handler.__calling) {
+			try {
+				handler.__calling = true;
+				handler.call(this, data);
+			} finally {
+				handler.__calling = false;
+			}
+		}
+	}
+}
+
+function flush(component) {
+	component._lock = true;
+	callAll(component._beforecreate);
+	callAll(component._oncreate);
+	callAll(component._aftercreate);
+	component._lock = false;
+}
+
+function get() {
+	return this._state;
+}
+
+function init(component, options) {
+	component._handlers = blankObject();
+	component._slots = blankObject();
+	component._bind = options._bind;
+	component._staged = {};
+
+	component.options = options;
+	component.root = options.root || component;
+	component.store = options.store || component.root.store;
+
+	if (!options.root) {
+		component._beforecreate = [];
+		component._oncreate = [];
+		component._aftercreate = [];
+	}
+}
+
+function on(eventName, handler) {
+	var handlers = this._handlers[eventName] || (this._handlers[eventName] = []);
+	handlers.push(handler);
+
+	return {
+		cancel: function() {
+			var index = handlers.indexOf(handler);
+			if (~index) handlers.splice(index, 1);
+		}
+	};
+}
+
+function set(newState) {
+	this._set(assign({}, newState));
+	if (this.root._lock) return;
+	flush(this.root);
+}
+
+function _set(newState) {
+	var oldState = this._state,
+		changed = {},
+		dirty = false;
+
+	newState = assign(this._staged, newState);
+	this._staged = {};
+
+	for (var key in newState) {
+		if (this._differs(newState[key], oldState[key])) changed[key] = dirty = true;
+	}
+	if (!dirty) return;
+
+	this._state = assign(assign({}, oldState), newState);
+	this._recompute(changed, this._state);
+	if (this._bind) this._bind(changed, this._state);
+
+	if (this._fragment) {
+		this.fire("state", { changed: changed, current: this._state, previous: oldState });
+		this._fragment.p(changed, this._state);
+		this.fire("update", { changed: changed, current: this._state, previous: oldState });
+	}
+}
+
+function _stage(newState) {
+	assign(this._staged, newState);
+}
+
+function callAll(fns) {
+	while (fns && fns.length) fns.shift()();
+}
+
+function _mount(target, anchor) {
+	this._fragment[this._fragment.i ? 'i' : 'm'](target, anchor || null);
+}
+
+var proto = {
+	destroy,
+	get,
+	fire,
+	on,
+	set,
+	_recompute: noop,
+	_set,
+	_stage,
+	_mount,
+	_differs
+};
+
+/* generated by Svelte vX.Y.Z */
+
+function create_main_fragment(component, ctx) {
+
+	var lazyload_initial_data = { load: () => import('./Foo.html') };
+	var lazyload = new LazyLoad({
+		root: component.root,
+		store: component.store,
+		data: lazyload_initial_data
+	});
+
+	return {
+		c() {
+			lazyload._fragment.c();
+		},
+
+		m(target, anchor) {
+			lazyload._mount(target, anchor);
+		},
+
+		p: noop,
+
+		d(detach) {
+			lazyload.destroy(detach);
+		}
+	};
+}
+
+function SvelteComponent(options) {
+	init(this, options);
+	this._state = assign({}, options.data);
+	this._intro = true;
+
+	this._fragment = create_main_fragment(this, this._state);
+
+	if (options.target) {
+		this._fragment.c();
+		this._mount(options.target, options.anchor);
+
+		flush(this);
+	}
+}
+
+assign(SvelteComponent.prototype, proto);
+
+export default SvelteComponent;

test/js/samples/dynamic-import/expected.js

@@ -0,0 +1,46 @@
+/* generated by Svelte vX.Y.Z */
+import { assign, flush, init, noop, proto } from "svelte/shared.js";
+
+function create_main_fragment(component, ctx) {
+
+	var lazyload_initial_data = { load: () => import('./Foo.html') };
+	var lazyload = new LazyLoad({
+		root: component.root,
+		store: component.store,
+		data: lazyload_initial_data
+	});
+
+	return {
+		c() {
+			lazyload._fragment.c();
+		},
+
+		m(target, anchor) {
+			lazyload._mount(target, anchor);
+		},
+
+		p: noop,
+
+		d(detach) {
+			lazyload.destroy(detach);
+		}
+	};
+}
+
+function SvelteComponent(options) {
+	init(this, options);
+	this._state = assign({}, options.data);
+	this._intro = true;
+
+	this._fragment = create_main_fragment(this, this._state);
+
+	if (options.target) {
+		this._fragment.c();
+		this._mount(options.target, options.anchor);
+
+		flush(this);
+	}
+}
+
+assign(SvelteComponent.prototype, proto);
+export default SvelteComponent;

test/js/samples/dynamic-import/input.html

@@ -0,0 +1,9 @@
+<LazyLoad load="{() => import('./Foo.html')}"/>
+
+<script>
+	export default {
+		components: {
+			LazyLoad
+		}
+	};
+</script>