mirror of
https://github.com/sveltejs/svelte.git
synced 2024-12-01 17:30:59 +01:00
190 lines
4.0 KiB
JavaScript
190 lines
4.0 KiB
JavaScript
function noop() {}
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function assign(target) {
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var k,
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source,
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i = 1,
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len = arguments.length;
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for (; i < len; i++) {
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source = arguments[i];
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for (k in source) target[k] = source[k];
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}
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return target;
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}
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function differs(a, b) {
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return a !== b || ((a && typeof a === 'object') || typeof a === 'function');
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}
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function dispatchObservers(component, group, newState, oldState) {
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for (var key in group) {
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if (!(key in newState)) continue;
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var newValue = newState[key];
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var oldValue = oldState[key];
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if (differs(newValue, oldValue)) {
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var callbacks = group[key];
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if (!callbacks) continue;
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for (var i = 0; i < callbacks.length; i += 1) {
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var callback = callbacks[i];
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if (callback.__calling) continue;
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callback.__calling = true;
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callback.call(component, newValue, oldValue);
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callback.__calling = false;
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}
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}
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}
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}
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function get(key) {
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return key ? this._state[key] : this._state;
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}
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function fire(eventName, data) {
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var handlers =
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eventName in this._handlers && this._handlers[eventName].slice();
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if (!handlers) return;
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for (var i = 0; i < handlers.length; i += 1) {
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handlers[i].call(this, data);
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}
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}
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function observe(key, callback, options) {
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var group = options && options.defer
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? this._observers.post
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: this._observers.pre;
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(group[key] || (group[key] = [])).push(callback);
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if (!options || options.init !== false) {
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callback.__calling = true;
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callback.call(this, this._state[key]);
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callback.__calling = false;
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}
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return {
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cancel: function() {
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var index = group[key].indexOf(callback);
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if (~index) group[key].splice(index, 1);
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}
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};
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}
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function on(eventName, handler) {
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if (eventName === 'teardown') return this.on('destroy', handler);
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var handlers = this._handlers[eventName] || (this._handlers[eventName] = []);
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handlers.push(handler);
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return {
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cancel: function() {
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var index = handlers.indexOf(handler);
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if (~index) handlers.splice(index, 1);
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}
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};
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}
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function set(newState) {
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this._set(assign({}, newState));
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if (this._root._block) return;
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this._root._block = true;
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callAll(this._root._beforecreate);
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callAll(this._root._oncreate);
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callAll(this._root._aftercreate);
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this._root._block = false;
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}
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function callAll(fns) {
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while (fns && fns.length) fns.pop()();
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}
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var proto = {
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get: get,
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fire: fire,
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observe: observe,
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on: on,
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set: set
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};
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function recompute ( state, newState, oldState, isInitial ) {
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if ( isInitial || ( 'x' in newState && differs( state.x, oldState.x ) ) ) {
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state.a = newState.a = template.computed.a( state.x );
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state.b = newState.b = template.computed.b( state.x );
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}
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}
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var template = (function () {
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return {
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computed: {
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a: x => x * 2,
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b: x => x * 3
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}
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};
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}());
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function create_main_fragment ( state, component ) {
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return {
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create: noop,
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mount: noop,
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unmount: noop,
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destroy: noop
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};
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}
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function SvelteComponent ( options ) {
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options = options || {};
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this._state = options.data || {};
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recompute( this._state, this._state, {}, true );
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this._observers = {
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pre: Object.create( null ),
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post: Object.create( null )
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};
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this._handlers = Object.create( null );
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this._root = options._root || this;
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this._yield = options._yield;
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this._torndown = false;
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this._fragment = create_main_fragment( this._state, this );
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if ( options.target ) {
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this._fragment.create();
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this._fragment.mount( options.target, null );
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}
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}
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assign( SvelteComponent.prototype, proto );
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SvelteComponent.prototype._set = function _set ( newState ) {
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var oldState = this._state;
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this._state = assign( {}, oldState, newState );
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recompute( this._state, newState, oldState, false );
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dispatchObservers( this, this._observers.pre, newState, oldState );
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dispatchObservers( this, this._observers.post, newState, oldState );
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};
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SvelteComponent.prototype.teardown = SvelteComponent.prototype.destroy = function destroy ( detach ) {
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this.fire( 'destroy' );
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if ( detach !== false ) this._fragment.unmount();
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this._fragment.destroy();
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this._fragment = null;
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this._state = {};
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this._torndown = true;
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};
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export default SvelteComponent;
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