package.lit-element.js.map Maven / Gradle / Ivy
Show all versions of lit-element Show documentation
{"version":3,"file":"lit-element.js","sources":["src/lit-element.ts"],"sourcesContent":["/**\n * @license\n * Copyright 2017 Google LLC\n * SPDX-License-Identifier: BSD-3-Clause\n */\n\n/**\n * The main LitElement module, which defines the {@linkcode LitElement} base\n * class and related APIs.\n *\n * LitElement components can define a template and a set of observed\n * properties. Changing an observed property triggers a re-render of the\n * element.\n *\n * Import {@linkcode LitElement} and {@linkcode html} from this module to\n * create a component:\n *\n * ```js\n * import {LitElement, html} from 'lit-element';\n *\n * class MyElement extends LitElement {\n *\n * // Declare observed properties\n * static get properties() {\n * return {\n * adjective: {}\n * }\n * }\n *\n * constructor() {\n * this.adjective = 'awesome';\n * }\n *\n * // Define the element's template\n * render() {\n * return html`your ${adjective} template here
`;\n * }\n * }\n *\n * customElements.define('my-element', MyElement);\n * ```\n *\n * `LitElement` extends {@linkcode ReactiveElement} and adds lit-html\n * templating. The `ReactiveElement` class is provided for users that want to\n * build their own custom element base classes that don't use lit-html.\n *\n * @packageDocumentation\n */\nimport {PropertyValues, ReactiveElement} from '@lit/reactive-element';\nimport {render, RenderOptions, noChange, RootPart} from 'lit-html';\nexport * from '@lit/reactive-element';\nexport * from 'lit-html';\n\nimport {LitUnstable} from 'lit-html';\nimport {ReactiveUnstable} from '@lit/reactive-element';\n\n/**\n * Contains types that are part of the unstable debug API.\n *\n * Everything in this API is not stable and may change or be removed in the future,\n * even on patch releases.\n */\n// eslint-disable-next-line @typescript-eslint/no-namespace\nexport namespace Unstable {\n /**\n * When Lit is running in dev mode and `window.emitLitDebugLogEvents` is true,\n * we will emit 'lit-debug' events to window, with live details about the update and render\n * lifecycle. These can be useful for writing debug tooling and visualizations.\n *\n * Please be aware that running with window.emitLitDebugLogEvents has performance overhead,\n * making certain operations that are normally very cheap (like a no-op render) much slower,\n * because we must copy data and dispatch events.\n */\n // eslint-disable-next-line @typescript-eslint/no-namespace\n export namespace DebugLog {\n export type Entry =\n | LitUnstable.DebugLog.Entry\n | ReactiveUnstable.DebugLog.Entry;\n }\n}\n/*\n * When using Closure Compiler, JSCompiler_renameProperty(property, object) is\n * replaced at compile time by the munged name for object[property]. We cannot\n * alias this function, so we have to use a small shim that has the same\n * behavior when not compiling.\n */\n/*@__INLINE__*/\nconst JSCompiler_renameProperty = (\n prop: P,\n _obj: unknown\n): P => prop;\n\nconst DEV_MODE = true;\n\nlet issueWarning: (code: string, warning: string) => void;\n\nif (DEV_MODE) {\n // Ensure warnings are issued only 1x, even if multiple versions of Lit\n // are loaded.\n const issuedWarnings: Set =\n (globalThis.litIssuedWarnings ??= new Set());\n\n // Issue a warning, if we haven't already.\n issueWarning = (code: string, warning: string) => {\n warning += ` See https://lit.dev/msg/${code} for more information.`;\n if (!issuedWarnings.has(warning)) {\n console.warn(warning);\n issuedWarnings.add(warning);\n }\n };\n}\n\n/**\n * Base element class that manages element properties and attributes, and\n * renders a lit-html template.\n *\n * To define a component, subclass `LitElement` and implement a\n * `render` method to provide the component's template. Define properties\n * using the {@linkcode LitElement.properties properties} property or the\n * {@linkcode property} decorator.\n */\nexport class LitElement extends ReactiveElement {\n // This property needs to remain unminified.\n static ['_$litElement$'] = true;\n\n /**\n * @category rendering\n */\n readonly renderOptions: RenderOptions = {host: this};\n\n private __childPart: RootPart | undefined = undefined;\n\n /**\n * @category rendering\n */\n protected override createRenderRoot() {\n const renderRoot = super.createRenderRoot();\n // When adoptedStyleSheets are shimmed, they are inserted into the\n // shadowRoot by createRenderRoot. Adjust the renderBefore node so that\n // any styles in Lit content render before adoptedStyleSheets. This is\n // important so that adoptedStyleSheets have precedence over styles in\n // the shadowRoot.\n this.renderOptions.renderBefore ??= renderRoot!.firstChild as ChildNode;\n return renderRoot;\n }\n\n /**\n * Updates the element. This method reflects property values to attributes\n * and calls `render` to render DOM via lit-html. Setting properties inside\n * this method will *not* trigger another update.\n * @param changedProperties Map of changed properties with old values\n * @category updates\n */\n protected override update(changedProperties: PropertyValues) {\n // Setting properties in `render` should not trigger an update. Since\n // updates are allowed after super.update, it's important to call `render`\n // before that.\n const value = this.render();\n if (!this.hasUpdated) {\n this.renderOptions.isConnected = this.isConnected;\n }\n super.update(changedProperties);\n this.__childPart = render(value, this.renderRoot, this.renderOptions);\n }\n\n /**\n * Invoked when the component is added to the document's DOM.\n *\n * In `connectedCallback()` you should setup tasks that should only occur when\n * the element is connected to the document. The most common of these is\n * adding event listeners to nodes external to the element, like a keydown\n * event handler added to the window.\n *\n * ```ts\n * connectedCallback() {\n * super.connectedCallback();\n * addEventListener('keydown', this._handleKeydown);\n * }\n * ```\n *\n * Typically, anything done in `connectedCallback()` should be undone when the\n * element is disconnected, in `disconnectedCallback()`.\n *\n * @category lifecycle\n */\n override connectedCallback() {\n super.connectedCallback();\n this.__childPart?.setConnected(true);\n }\n\n /**\n * Invoked when the component is removed from the document's DOM.\n *\n * This callback is the main signal to the element that it may no longer be\n * used. `disconnectedCallback()` should ensure that nothing is holding a\n * reference to the element (such as event listeners added to nodes external\n * to the element), so that it is free to be garbage collected.\n *\n * ```ts\n * disconnectedCallback() {\n * super.disconnectedCallback();\n * window.removeEventListener('keydown', this._handleKeydown);\n * }\n * ```\n *\n * An element may be re-connected after being disconnected.\n *\n * @category lifecycle\n */\n override disconnectedCallback() {\n super.disconnectedCallback();\n this.__childPart?.setConnected(false);\n }\n\n /**\n * Invoked on each update to perform rendering tasks. This method may return\n * any value renderable by lit-html's `ChildPart` - typically a\n * `TemplateResult`. Setting properties inside this method will *not* trigger\n * the element to update.\n * @category rendering\n */\n protected render(): unknown {\n return noChange;\n }\n}\n\n/**\n * Ensure this class is marked as `finalized` as an optimization ensuring\n * it will not needlessly try to `finalize`.\n *\n * Note this property name is a string to prevent breaking Closure JS Compiler\n * optimizations. See @lit/reactive-element for more information.\n */\n(LitElement as unknown as Record)[\n JSCompiler_renameProperty('finalized', LitElement)\n] = true;\n\n// Install hydration if available\nglobalThis.litElementHydrateSupport?.({LitElement});\n\n// Apply polyfills if available\nconst polyfillSupport = DEV_MODE\n ? globalThis.litElementPolyfillSupportDevMode\n : globalThis.litElementPolyfillSupport;\npolyfillSupport?.({LitElement});\n\n/**\n * END USERS SHOULD NOT RELY ON THIS OBJECT.\n *\n * Private exports for use by other Lit packages, not intended for use by\n * external users.\n *\n * We currently do not make a mangled rollup build of the lit-ssr code. In order\n * to keep a number of (otherwise private) top-level exports mangled in the\n * client side code, we export a _$LE object containing those members (or\n * helper methods for accessing private fields of those members), and then\n * re-export them for use in lit-ssr. This keeps lit-ssr agnostic to whether the\n * client-side code is being used in `dev` mode or `prod` mode.\n *\n * This has a unique name, to disambiguate it from private exports in\n * lit-html, since this module re-exports all of lit-html.\n *\n * @private\n */\nexport const _$LE = {\n _$attributeToProperty: (\n el: LitElement,\n name: string,\n value: string | null\n ) => {\n // eslint-disable-next-line\n (el as any)._$attributeToProperty(name, value);\n },\n // eslint-disable-next-line\n _$changedProperties: (el: LitElement) => (el as any)._$changedProperties,\n};\n\n// IMPORTANT: do not change the property name or the assignment expression.\n// This line will be used in regexes to search for LitElement usage.\n(globalThis.litElementVersions ??= []).push('4.0.6');\nif (DEV_MODE && globalThis.litElementVersions.length > 1) {\n issueWarning!(\n 'multiple-versions',\n `Multiple versions of Lit loaded. Loading multiple versions ` +\n `is not recommended.`\n );\n}\n"],"names":["LitElement","ReactiveElement","constructor","this","renderOptions","host","__childPart","undefined","createRenderRoot","renderRoot","super","renderBefore","firstChild","update","changedProperties","value","render","hasUpdated","isConnected","connectedCallback","setConnected","disconnectedCallback","noChange","globalThis","litElementHydrateSupport","polyfillSupport","litElementPolyfillSupport","_$LE","_$attributeToProperty","el","name","_$changedProperties","litElementVersions","push"],"mappings":";;;;;GAyHM,MAAOA,UAAmBC,EAAhC,WAAAC,uBAOWC,KAAAC,cAA+B,CAACC,KAAMF,MAEvCA,KAAWG,UAAyBC,CA8F7C,CAzFoB,gBAAAC,GACjB,MAAMC,EAAaC,MAAMF,mBAOzB,OADAL,KAAKC,cAAcO,eAAiBF,EAAYG,WACzCH,CACR,CASkB,MAAAI,CAAOC,GAIxB,MAAMC,EAAQZ,KAAKa,SACdb,KAAKc,aACRd,KAAKC,cAAcc,YAAcf,KAAKe,aAExCR,MAAMG,OAAOC,GACbX,KAAKG,KAAcU,EAAOD,EAAOZ,KAAKM,WAAYN,KAAKC,cACxD,CAsBQ,iBAAAe,GACPT,MAAMS,oBACNhB,KAAKG,MAAac,cAAa,EAChC,CAqBQ,oBAAAC,GACPX,MAAMW,uBACNlB,KAAKG,MAAac,cAAa,EAChC,CASS,MAAAJ,GACR,OAAOM,CACR,EApGMtB,EAAgB,eAAI,EA8G5BA,GAC2B,2BACxB,EAGJuB,WAAWC,2BAA2B,CAACxB,eAGvC,MAAMyB,EAEFF,WAAWG,0BACfD,IAAkB,CAACzB,eAoBN,MAAA2B,EAAO,CAClBC,KAAuB,CACrBC,EACAC,EACAf,KAGCc,EAAWD,KAAsBE,EAAMf,EAAM,EAGhDgB,KAAsBF,GAAoBA,EAAWE,OAKtDR,WAAWS,qBAAuB,IAAIC,KAAK"}