diff --git a/src/generators/dom/visitors/Element/Attribute.ts b/src/generators/dom/visitors/Element/Attribute.ts
index 837e0945dbfa..2baf4a7d969d 100644
--- a/src/generators/dom/visitors/Element/Attribute.ts
+++ b/src/generators/dom/visitors/Element/Attribute.ts
@@ -3,7 +3,6 @@ import deindent from '../../../../utils/deindent';
import visitStyleAttribute, { optimizeStyle } from './StyleAttribute';
import { stringify } from '../../../../utils/stringify';
import getExpressionPrecedence from '../../../../utils/getExpressionPrecedence';
-import getStaticAttributeValue from '../../../../utils/getStaticAttributeValue';
import { DomGenerator } from '../../index';
import Block from '../../Block';
import { Node } from '../../../../interfaces';
@@ -56,6 +55,11 @@ export default function visitAttribute(
const isLegacyInputType = generator.legacy && name === 'type' && node.name === 'input';
+ const isDataSet = /^data-/.test(name) && !generator.legacy;
+ const camelCaseName = isDataSet ? name.replace('data-', '').replace(/(-\w)/g, function (m) {
+ return m[1].toUpperCase();
+ }) : name;
+
if (isDynamic) {
let value;
@@ -163,6 +167,11 @@ export default function visitAttribute(
`${state.parentNode}.${propertyName} = ${init};`
);
updater = `${state.parentNode}.${propertyName} = ${shouldCache || isSelectValueAttribute ? last : value};`;
+ } else if (isDataSet) {
+ block.builders.hydrate.addLine(
+ `${state.parentNode}.dataset.${camelCaseName} = ${init};`
+ );
+ updater = `${state.parentNode}.dataset.${camelCaseName} = ${shouldCache || isSelectValueAttribute ? last : value};`;
} else {
block.builders.hydrate.addLine(
`${method}(${state.parentNode}, "${name}", ${init});`
@@ -198,6 +207,7 @@ export default function visitAttribute(
const statement = (
isLegacyInputType ? `@setInputType(${state.parentNode}, ${value});` :
propertyName ? `${state.parentNode}.${propertyName} = ${value};` :
+ isDataSet ? `${state.parentNode}.dataset.${camelCaseName} = ${value};` :
`${method}(${state.parentNode}, "${name}", ${value});`
);
@@ -221,4 +231,4 @@ export default function visitAttribute(
block.builders.hydrate.addLine(updateValue);
if (isDynamic) block.builders.update.addLine(updateValue);
}
-}
\ No newline at end of file
+}
diff --git a/test/js/samples/do-use-dataset/expected-bundle.js b/test/js/samples/do-use-dataset/expected-bundle.js
new file mode 100644
index 000000000000..efd52585f3b1
--- /dev/null
+++ b/test/js/samples/do-use-dataset/expected-bundle.js
@@ -0,0 +1,236 @@
+function noop() {}
+
+function assign(target) {
+ var k,
+ source,
+ i = 1,
+ len = arguments.length;
+ for (; i < len; i++) {
+ source = arguments[i];
+ for (k in source) target[k] = source[k];
+ }
+
+ return target;
+}
+
+function insertNode(node, target, anchor) {
+ target.insertBefore(node, anchor);
+}
+
+function detachNode(node) {
+ node.parentNode.removeChild(node);
+}
+
+function createElement(name) {
+ return document.createElement(name);
+}
+
+function createText(data) {
+ return document.createTextNode(data);
+}
+
+function blankObject() {
+ return Object.create(null);
+}
+
+function destroy(detach) {
+ this.destroy = noop;
+ this.fire('destroy');
+ this.set = this.get = noop;
+
+ if (detach !== false) this._fragment.u();
+ this._fragment.d();
+ this._fragment = this._state = null;
+}
+
+function differs(a, b) {
+ return a !== b || ((a && typeof a === 'object') || typeof a === 'function');
+}
+
+function dispatchObservers(component, group, changed, newState, oldState) {
+ for (var key in group) {
+ if (!changed[key]) continue;
+
+ var newValue = newState[key];
+ var oldValue = oldState[key];
+
+ var callbacks = group[key];
+ if (!callbacks) continue;
+
+ for (var i = 0; i < callbacks.length; i += 1) {
+ var callback = callbacks[i];
+ if (callback.__calling) continue;
+
+ callback.__calling = true;
+ callback.call(component, newValue, oldValue);
+ callback.__calling = false;
+ }
+ }
+}
+
+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) {
+ handlers[i].call(this, data);
+ }
+}
+
+function get(key) {
+ return key ? this._state[key] : this._state;
+}
+
+function init(component, options) {
+ component.options = options;
+
+ component._observers = { pre: blankObject(), post: blankObject() };
+ component._handlers = blankObject();
+ component._root = options._root || component;
+ component._bind = options._bind;
+}
+
+function observe(key, callback, options) {
+ var group = options && options.defer
+ ? this._observers.post
+ : this._observers.pre;
+
+ (group[key] || (group[key] = [])).push(callback);
+
+ if (!options || options.init !== false) {
+ callback.__calling = true;
+ callback.call(this, this._state[key]);
+ callback.__calling = false;
+ }
+
+ return {
+ cancel: function() {
+ var index = group[key].indexOf(callback);
+ if (~index) group[key].splice(index, 1);
+ }
+ };
+}
+
+function on(eventName, handler) {
+ if (eventName === 'teardown') return this.on('destroy', 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;
+ this._root._lock = true;
+ callAll(this._root._beforecreate);
+ callAll(this._root._oncreate);
+ callAll(this._root._aftercreate);
+ this._root._lock = false;
+}
+
+function _set(newState) {
+ var oldState = this._state,
+ changed = {},
+ dirty = false;
+
+ for (var key in newState) {
+ if (differs(newState[key], oldState[key])) changed[key] = dirty = true;
+ }
+ if (!dirty) return;
+
+ this._state = assign({}, oldState, newState);
+ this._recompute(changed, this._state);
+ if (this._bind) this._bind(changed, this._state);
+ dispatchObservers(this, this._observers.pre, changed, this._state, oldState);
+ this._fragment.p(changed, this._state);
+ dispatchObservers(this, this._observers.post, changed, this._state, oldState);
+}
+
+function callAll(fns) {
+ while (fns && fns.length) fns.pop()();
+}
+
+function _mount(target, anchor) {
+ this._fragment.m(target, anchor);
+}
+
+function _unmount() {
+ this._fragment.u();
+}
+
+var proto = {
+ destroy: destroy,
+ get: get,
+ fire: fire,
+ observe: observe,
+ on: on,
+ set: set,
+ teardown: destroy,
+ _recompute: noop,
+ _set: _set,
+ _mount: _mount,
+ _unmount: _unmount
+};
+
+/* generated by Svelte vX.Y.Z */
+function create_main_fragment(state, component) {
+ var div, text, div_1;
+
+ return {
+ c: function create() {
+ div = createElement("div");
+ text = createText("\n");
+ div_1 = createElement("div");
+ this.h();
+ },
+
+ h: function hydrate() {
+ div.dataset.foo = "bar";
+ div_1.dataset.foo = state.bar;
+ },
+
+ m: function mount(target, anchor) {
+ insertNode(div, target, anchor);
+ insertNode(text, target, anchor);
+ insertNode(div_1, target, anchor);
+ },
+
+ p: function update(changed, state) {
+ if (changed.bar) {
+ div_1.dataset.foo = state.bar;
+ }
+ },
+
+ u: function unmount() {
+ detachNode(div);
+ detachNode(text);
+ detachNode(div_1);
+ },
+
+ d: noop
+ };
+}
+
+function SvelteComponent(options) {
+ init(this, options);
+ this._state = assign({}, options.data);
+
+ this._fragment = create_main_fragment(this._state, this);
+
+ if (options.target) {
+ this._fragment.c();
+ this._fragment.m(options.target, options.anchor || null);
+ }
+}
+
+assign(SvelteComponent.prototype, proto);
+
+export default SvelteComponent;
diff --git a/test/js/samples/do-use-dataset/expected.js b/test/js/samples/do-use-dataset/expected.js
new file mode 100644
index 000000000000..7e67abbfa0e3
--- /dev/null
+++ b/test/js/samples/do-use-dataset/expected.js
@@ -0,0 +1,55 @@
+/* generated by Svelte vX.Y.Z */
+import { assign, createElement, createText, detachNode, init, insertNode, noop, proto } from "svelte/shared.js";
+
+function create_main_fragment(state, component) {
+ var div, text, div_1;
+
+ return {
+ c: function create() {
+ div = createElement("div");
+ text = createText("\n");
+ div_1 = createElement("div");
+ this.h();
+ },
+
+ h: function hydrate() {
+ div.dataset.foo = "bar";
+ div_1.dataset.foo = state.bar;
+ },
+
+ m: function mount(target, anchor) {
+ insertNode(div, target, anchor);
+ insertNode(text, target, anchor);
+ insertNode(div_1, target, anchor);
+ },
+
+ p: function update(changed, state) {
+ if (changed.bar) {
+ div_1.dataset.foo = state.bar;
+ }
+ },
+
+ u: function unmount() {
+ detachNode(div);
+ detachNode(text);
+ detachNode(div_1);
+ },
+
+ d: noop
+ };
+}
+
+function SvelteComponent(options) {
+ init(this, options);
+ this._state = assign({}, options.data);
+
+ this._fragment = create_main_fragment(this._state, this);
+
+ if (options.target) {
+ this._fragment.c();
+ this._fragment.m(options.target, options.anchor || null);
+ }
+}
+
+assign(SvelteComponent.prototype, proto);
+export default SvelteComponent;
diff --git a/test/js/samples/do-use-dataset/input.html b/test/js/samples/do-use-dataset/input.html
new file mode 100644
index 000000000000..acd9d623b44b
--- /dev/null
+++ b/test/js/samples/do-use-dataset/input.html
@@ -0,0 +1,2 @@
+
+
diff --git a/test/js/samples/dont-use-dataset-in-legacy/_config.js b/test/js/samples/dont-use-dataset-in-legacy/_config.js
new file mode 100644
index 000000000000..67924a4ffed2
--- /dev/null
+++ b/test/js/samples/dont-use-dataset-in-legacy/_config.js
@@ -0,0 +1,5 @@
+export default {
+ options: {
+ legacy: true
+ }
+};
diff --git a/test/js/samples/dont-use-dataset-in-legacy/expected-bundle.js b/test/js/samples/dont-use-dataset-in-legacy/expected-bundle.js
new file mode 100644
index 000000000000..4eaea5ee0a2a
--- /dev/null
+++ b/test/js/samples/dont-use-dataset-in-legacy/expected-bundle.js
@@ -0,0 +1,240 @@
+function noop() {}
+
+function assign(target) {
+ var k,
+ source,
+ i = 1,
+ len = arguments.length;
+ for (; i < len; i++) {
+ source = arguments[i];
+ for (k in source) target[k] = source[k];
+ }
+
+ return target;
+}
+
+function insertNode(node, target, anchor) {
+ target.insertBefore(node, anchor);
+}
+
+function detachNode(node) {
+ node.parentNode.removeChild(node);
+}
+
+function createElement(name) {
+ return document.createElement(name);
+}
+
+function createText(data) {
+ return document.createTextNode(data);
+}
+
+function setAttribute(node, attribute, value) {
+ node.setAttribute(attribute, value);
+}
+
+function blankObject() {
+ return Object.create(null);
+}
+
+function destroy(detach) {
+ this.destroy = noop;
+ this.fire('destroy');
+ this.set = this.get = noop;
+
+ if (detach !== false) this._fragment.u();
+ this._fragment.d();
+ this._fragment = this._state = null;
+}
+
+function differs(a, b) {
+ return a !== b || ((a && typeof a === 'object') || typeof a === 'function');
+}
+
+function dispatchObservers(component, group, changed, newState, oldState) {
+ for (var key in group) {
+ if (!changed[key]) continue;
+
+ var newValue = newState[key];
+ var oldValue = oldState[key];
+
+ var callbacks = group[key];
+ if (!callbacks) continue;
+
+ for (var i = 0; i < callbacks.length; i += 1) {
+ var callback = callbacks[i];
+ if (callback.__calling) continue;
+
+ callback.__calling = true;
+ callback.call(component, newValue, oldValue);
+ callback.__calling = false;
+ }
+ }
+}
+
+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) {
+ handlers[i].call(this, data);
+ }
+}
+
+function get(key) {
+ return key ? this._state[key] : this._state;
+}
+
+function init(component, options) {
+ component.options = options;
+
+ component._observers = { pre: blankObject(), post: blankObject() };
+ component._handlers = blankObject();
+ component._root = options._root || component;
+ component._bind = options._bind;
+}
+
+function observe(key, callback, options) {
+ var group = options && options.defer
+ ? this._observers.post
+ : this._observers.pre;
+
+ (group[key] || (group[key] = [])).push(callback);
+
+ if (!options || options.init !== false) {
+ callback.__calling = true;
+ callback.call(this, this._state[key]);
+ callback.__calling = false;
+ }
+
+ return {
+ cancel: function() {
+ var index = group[key].indexOf(callback);
+ if (~index) group[key].splice(index, 1);
+ }
+ };
+}
+
+function on(eventName, handler) {
+ if (eventName === 'teardown') return this.on('destroy', 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;
+ this._root._lock = true;
+ callAll(this._root._beforecreate);
+ callAll(this._root._oncreate);
+ callAll(this._root._aftercreate);
+ this._root._lock = false;
+}
+
+function _set(newState) {
+ var oldState = this._state,
+ changed = {},
+ dirty = false;
+
+ for (var key in newState) {
+ if (differs(newState[key], oldState[key])) changed[key] = dirty = true;
+ }
+ if (!dirty) return;
+
+ this._state = assign({}, oldState, newState);
+ this._recompute(changed, this._state);
+ if (this._bind) this._bind(changed, this._state);
+ dispatchObservers(this, this._observers.pre, changed, this._state, oldState);
+ this._fragment.p(changed, this._state);
+ dispatchObservers(this, this._observers.post, changed, this._state, oldState);
+}
+
+function callAll(fns) {
+ while (fns && fns.length) fns.pop()();
+}
+
+function _mount(target, anchor) {
+ this._fragment.m(target, anchor);
+}
+
+function _unmount() {
+ this._fragment.u();
+}
+
+var proto = {
+ destroy: destroy,
+ get: get,
+ fire: fire,
+ observe: observe,
+ on: on,
+ set: set,
+ teardown: destroy,
+ _recompute: noop,
+ _set: _set,
+ _mount: _mount,
+ _unmount: _unmount
+};
+
+/* generated by Svelte vX.Y.Z */
+function create_main_fragment(state, component) {
+ var div, text, div_1;
+
+ return {
+ c: function create() {
+ div = createElement("div");
+ text = createText("\n");
+ div_1 = createElement("div");
+ this.h();
+ },
+
+ h: function hydrate() {
+ setAttribute(div, "data-foo", "bar");
+ setAttribute(div_1, "data-foo", state.bar);
+ },
+
+ m: function mount(target, anchor) {
+ insertNode(div, target, anchor);
+ insertNode(text, target, anchor);
+ insertNode(div_1, target, anchor);
+ },
+
+ p: function update(changed, state) {
+ if (changed.bar) {
+ setAttribute(div_1, "data-foo", state.bar);
+ }
+ },
+
+ u: function unmount() {
+ detachNode(div);
+ detachNode(text);
+ detachNode(div_1);
+ },
+
+ d: noop
+ };
+}
+
+function SvelteComponent(options) {
+ init(this, options);
+ this._state = assign({}, options.data);
+
+ this._fragment = create_main_fragment(this._state, this);
+
+ if (options.target) {
+ this._fragment.c();
+ this._fragment.m(options.target, options.anchor || null);
+ }
+}
+
+assign(SvelteComponent.prototype, proto);
+
+export default SvelteComponent;
diff --git a/test/js/samples/dont-use-dataset-in-legacy/expected.js b/test/js/samples/dont-use-dataset-in-legacy/expected.js
new file mode 100644
index 000000000000..a10c40c13d73
--- /dev/null
+++ b/test/js/samples/dont-use-dataset-in-legacy/expected.js
@@ -0,0 +1,55 @@
+/* generated by Svelte vX.Y.Z */
+import { assign, createElement, createText, detachNode, init, insertNode, noop, proto, setAttribute } from "svelte/shared.js";
+
+function create_main_fragment(state, component) {
+ var div, text, div_1;
+
+ return {
+ c: function create() {
+ div = createElement("div");
+ text = createText("\n");
+ div_1 = createElement("div");
+ this.h();
+ },
+
+ h: function hydrate() {
+ setAttribute(div, "data-foo", "bar");
+ setAttribute(div_1, "data-foo", state.bar);
+ },
+
+ m: function mount(target, anchor) {
+ insertNode(div, target, anchor);
+ insertNode(text, target, anchor);
+ insertNode(div_1, target, anchor);
+ },
+
+ p: function update(changed, state) {
+ if (changed.bar) {
+ setAttribute(div_1, "data-foo", state.bar);
+ }
+ },
+
+ u: function unmount() {
+ detachNode(div);
+ detachNode(text);
+ detachNode(div_1);
+ },
+
+ d: noop
+ };
+}
+
+function SvelteComponent(options) {
+ init(this, options);
+ this._state = assign({}, options.data);
+
+ this._fragment = create_main_fragment(this._state, this);
+
+ if (options.target) {
+ this._fragment.c();
+ this._fragment.m(options.target, options.anchor || null);
+ }
+}
+
+assign(SvelteComponent.prototype, proto);
+export default SvelteComponent;
diff --git a/test/js/samples/dont-use-dataset-in-legacy/input.html b/test/js/samples/dont-use-dataset-in-legacy/input.html
new file mode 100644
index 000000000000..acd9d623b44b
--- /dev/null
+++ b/test/js/samples/dont-use-dataset-in-legacy/input.html
@@ -0,0 +1,2 @@
+
+