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/**
* Copyright 2015 The AMP HTML Authors. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS-IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import {Layout, getLayoutClass, getLengthNumeral, getLengthUnits,
isInternalElement, isLayoutSizeDefined, isLoadingAllowed,
parseLayout, parseLength, getNaturalDimensions,
hasNaturalDimensions} from './layout';
import {ElementStub, stubbedElements} from './element-stub';
import {createLoaderElement} from '../src/loader';
import {dev, rethrowAsync, user} from './log';
import {getIntersectionChangeEntry} from '../src/intersection-observer';
import {parseSizeList} from './size-list';
import {reportError} from './error';
import {resourcesFor} from './resources';
import {timer} from './timer';
import {vsyncFor} from './vsync';
import {getServicePromise, getServicePromiseOrNull} from './service';
import * as dom from './dom';
const TAG_ = 'CustomElement';
/**
* This is the minimum width of the element needed to trigger `loading`
* animation. This value is justified as about 1/3 of a smallish mobile
* device viewport. Trying to put a loading indicator into a small element
* is meaningless.
* @private @const {number}
*/
const MIN_WIDTH_FOR_LOADING_ = 100;
/**
* The elements positioned ahead of this threshold may have their loading
* indicator initialized faster. This is benefitial to avoid relayout during
* render phase or scrolling.
* @private @const {number}
*/
const PREPARE_LOADING_THRESHOLD_ = 1000;
/**
* Map from element name to implementation class.
* @const {Object}
*/
const knownElements = {};
/**
* Whether this platform supports template tags.
* @const {boolean}
*/
const TEMPLATE_TAG_SUPPORTED = 'content' in window.document.createElement(
'template'
);
/**
* Registers an element. Upgrades it if has previously been stubbed.
* @param {!Window} win
* @param {string}
* @param {function(!Function)} toClass
*/
export function upgradeOrRegisterElement(win, name, toClass) {
if (!knownElements[name]) {
registerElement(win, name, toClass);
return;
}
user.assert(knownElements[name] == ElementStub,
'%s is already registered. The script tag for ' +
'%s is likely included twice in the page.', name, name);
for (let i = 0; i < stubbedElements.length; i++) {
const stub = stubbedElements[i];
// There are 3 possible states here:
// 1. We never made the stub because the extended impl. loaded first.
// In that case the element won't be in the array.
// 2. We made a stub but the browser didn't attach it yet. In
// that case we don't need to upgrade but simply switch to the new
// implementation.
// 3. A stub was attached. We upgrade which means we replay the
// implementation.
const element = stub.element;
if (element.tagName.toLowerCase() == name) {
try {
element.upgrade(toClass);
} catch (e) {
reportError(e, this);
}
}
}
}
/**
* Stub extended elements missing an implementation.
* @param {!Window} win
*/
export function stubElements(win) {
if (!win.ampExtendedElements) {
win.ampExtendedElements = {};
}
const list = win.document.querySelectorAll('[custom-element]');
for (let i = 0; i < list.length; i++) {
const name = list[i].getAttribute('custom-element');
win.ampExtendedElements[name] = true;
if (knownElements[name]) {
continue;
}
registerElement(win, name, ElementStub);
}
// Repeat stubbing when HEAD is complete.
if (!win.document.body) {
dom.waitForBody(win.document, () => stubElements(win));
}
}
/**
* Applies layout to the element. Visible for testing only.
* @param {!AmpElement} element
*/
export function applyLayout_(element) {
const layoutAttr = element.getAttribute('layout');
const widthAttr = element.getAttribute('width');
const heightAttr = element.getAttribute('height');
const sizesAttr = element.getAttribute('sizes');
const heightsAttr = element.getAttribute('heights');
// Input layout attributes.
const inputLayout = layoutAttr ? parseLayout(layoutAttr) : null;
user.assert(inputLayout !== undefined, 'Unknown layout: %s', layoutAttr);
const inputWidth = (widthAttr && widthAttr != 'auto') ?
parseLength(widthAttr) : widthAttr;
user.assert(inputWidth !== undefined, 'Invalid width value: %s', widthAttr);
const inputHeight = heightAttr ? parseLength(heightAttr) : null;
user.assert(inputHeight !== undefined, 'Invalid height value: %s',
heightAttr);
// Effective layout attributes. These are effectively constants.
let width;
let height;
let layout;
// Calculate effective width and height.
if ((!inputLayout || inputLayout == Layout.FIXED ||
inputLayout == Layout.FIXED_HEIGHT) &&
(!inputWidth || !inputHeight) && hasNaturalDimensions(element.tagName)) {
// Default width and height: handle elements that do not specify a
// width/height and are defined to have natural browser dimensions.
const dimensions = getNaturalDimensions(element);
width = (inputWidth || inputLayout == Layout.FIXED_HEIGHT) ? inputWidth :
dimensions.width;
height = inputHeight || dimensions.height;
} else {
width = inputWidth;
height = inputHeight;
}
// Calculate effective layout.
if (inputLayout) {
layout = inputLayout;
} else if (!width && !height) {
layout = Layout.CONTAINER;
} else if (height && (!width || width == 'auto')) {
layout = Layout.FIXED_HEIGHT;
} else if (height && width && (sizesAttr || heightsAttr)) {
layout = Layout.RESPONSIVE;
} else {
layout = Layout.FIXED;
}
// Verify layout attributes.
if (layout == Layout.FIXED || layout == Layout.FIXED_HEIGHT ||
layout == Layout.RESPONSIVE) {
user.assert(height, 'Expected height to be available: %s', heightAttr);
}
if (layout == Layout.FIXED_HEIGHT) {
user.assert(!width || width == 'auto',
'Expected width to be either absent or equal "auto" ' +
'for fixed-height layout: %s', widthAttr);
}
if (layout == Layout.FIXED || layout == Layout.RESPONSIVE) {
user.assert(width && width != 'auto',
'Expected width to be available and not equal to "auto": %s',
widthAttr);
}
if (layout == Layout.RESPONSIVE) {
user.assert(getLengthUnits(width) == getLengthUnits(height),
'Length units should be the same for width and height: %s, %s',
widthAttr, heightAttr);
} else {
user.assert(heightsAttr === null,
'Unexpected "heights" attribute for none-responsive layout');
}
// Apply UI.
element.classList.add(getLayoutClass(layout));
if (isLayoutSizeDefined(layout)) {
element.classList.add('-amp-layout-size-defined');
}
if (layout == Layout.NODISPLAY) {
element.style.display = 'none';
} else if (layout == Layout.FIXED) {
element.style.width = width;
element.style.height = height;
} else if (layout == Layout.FIXED_HEIGHT) {
element.style.height = height;
} else if (layout == Layout.RESPONSIVE) {
const sizer = element.ownerDocument.createElement('i-amp-sizer');
sizer.style.display = 'block';
sizer.style.paddingTop =
((getLengthNumeral(height) / getLengthNumeral(width)) * 100) + '%';
element.insertBefore(sizer, element.firstChild);
element.sizerElement_ = sizer;
} else if (layout == Layout.FILL) {
// Do nothing.
} else if (layout == Layout.CONTAINER) {
// Do nothing. Elements themselves will check whether the supplied
// layout value is acceptable. In particular container is only OK
// sometimes.
}
return layout;
}
/**
* Returns "true" for internal AMP nodes or for placeholder elements.
* @param {!Node} node
* @return {boolean}
*/
function isInternalOrServiceNode(node) {
if (isInternalElement(node)) {
return true;
}
if (node.tagName && (node.hasAttribute('placeholder') ||
node.hasAttribute('fallback') ||
node.hasAttribute('overflow'))) {
return true;
}
return false;
}
/**
* The interface that is implemented by all custom elements in the AMP
* namespace.
* @interface
*/
class AmpElement {
// TODO(dvoytenko): Add all exposed methods.
}
/**
* Creates a new custom element class prototype.
*
* Visible for testing only.
*
* @param {!Window} win The window in which to register the elements.
* @param {string} name Name of the custom element
* @param {function(new:BaseElement, !Element)} implementationClass
* @return {!AmpElement.prototype}
*/
export function createAmpElementProto(win, name, implementationClass) {
/**
* @lends {AmpElement.prototype}
*/
const ElementProto = win.Object.create(win.HTMLElement.prototype);
/**
* Called when elements is created. Sets instance vars since there is no
* constructor.
* @final
*/
ElementProto.createdCallback = function() {
this.classList.add('-amp-element');
// Flag "notbuilt" is removed by Resource manager when the resource is
// considered to be built. See "setBuilt" method.
/** @private {boolean} */
this.built_ = false;
this.classList.add('-amp-notbuilt');
this.classList.add('amp-notbuilt');
this.readyState = 'loading';
this.everAttached = false;
/** @private @const {!Resources} */
this.resources_ = resourcesFor(win);
/** @private {!Layout} */
this.layout_ = Layout.NODISPLAY;
/** @private {number} */
this.layoutWidth_ = -1;
/** @private {number} */
this.layoutCount_ = 0;
/** @private {boolean} */
this.isInViewport_ = false;
/** @private {string|null|undefined} */
this.mediaQuery_ = undefined;
/** @private {!SizeList|null|undefined} */
this.sizeList_ = undefined;
/** @private {!SizeList|null|undefined} */
this.heightsList_ = undefined;
/**
* This element can be assigned by the {@link applyLayout_} to a child
* element that will be used to size this element.
* @private {?Element}
*/
this.sizerElement_ = null;
/** @private {boolean|undefined} */
this.loadingDisabled_ = undefined;
/** @private {boolean|undefined} */
this.loadingState_ = undefined;
/** @private {?Element} */
this.loadingContainer_ = null;
/** @private {?Element} */
this.loadingElement_ = null;
/** @private {?Element|undefined} */
this.overflowElement_ = undefined;
/** @private {!BaseElement} */
this.implementation_ = new implementationClass(this);
this.implementation_.createdCallback();
/**
* Action queue is initially created and kept around until the element
* is ready to send actions directly to the implementation.
* @private {?Array<!ActionInvocation>}
*/
this.actionQueue_ = [];
/**
* Whether the element is in the template.
* @private {boolean|undefined}
*/
this.isInTemplate_ = undefined;
};
/** @private */
ElementProto.assertNotTemplate_ = function() {
dev.assert(!this.isInTemplate_, 'Must never be called in template');
};
/**
* Whether the element has been upgraded yet.
* @return {boolean}
* @final
*/
ElementProto.isUpgraded = function() {
return !(this.implementation_ instanceof ElementStub);
};
/**
* Upgrades the element to the provided new implementation. If element
* has already been attached, it's layout validation and attachment flows
* are repeated for the new implementation.
* @param {function(new:BaseElement, !Element)} newImplClass
* @final @package
*/
ElementProto.upgrade = function(newImplClass) {
if (this.isInTemplate_) {
return;
}
this.implementation_ = new newImplClass(this);
this.classList.remove('amp-unresolved');
this.classList.remove('-amp-unresolved');
this.implementation_.createdCallback();
if (this.layout_ != Layout.NODISPLAY &&
!this.implementation_.isLayoutSupported(this.layout_)) {
throw new Error('Layout not supported: ' + this.layout_);
}
this.implementation_.layout_ = this.layout_;
this.implementation_.layoutWidth_ = this.layoutWidth_;
if (this.everAttached) {
this.implementation_.firstAttachedCallback();
this.dispatchCustomEvent('amp:attached');
}
this.resources_.upgraded(this);
};
/**
* Whether the element has been built. A built element had its
* {@link buildCallback} method successfully invoked.
* @return {boolean}
* @final
*/
ElementProto.isBuilt = function() {
return this.built_;
};
/**
* Requests or requires the element to be built. The build is done by
* invoking {@link BaseElement.buildCallback} method.
*
* If the "force" argument is "false", the element will first check if
* implementation is ready to build by calling
* {@link BaseElement.isReadyToBuild} method. If this method returns "true"
* the build proceeds, otherwise no build is done.
*
* If the "force" argument is "true", the element performs build regardless
* of what {@link BaseElement.isReadyToBuild} would return.
*
* Returned value indicates whether or not build has been performed.
*
* This method can only be called on a upgraded element.
*
* @param {boolean} force Whether or not force the build.
* @return {boolean}
* @final
*/
ElementProto.build = function(force) {
this.assertNotTemplate_();
if (this.isBuilt()) {
return true;
}
dev.assert(this.isUpgraded(), 'Cannot build unupgraded element');
if (!force && !this.implementation_.isReadyToBuild()) {
return false;
}
try {
this.implementation_.buildCallback();
this.preconnect(/* onLayout */ false);
this.built_ = true;
this.classList.remove('-amp-notbuilt');
this.classList.remove('amp-notbuilt');
} catch (e) {
reportError(e, this);
throw e;
}
if (this.built_ && this.isInViewport_) {
this.updateInViewport_(true);
}
if (this.actionQueue_) {
if (this.actionQueue_.length > 0) {
// Only schedule when the queue is not empty, which should be
// the case 99% of the time.
timer.delay(this.dequeueActions_.bind(this), 1);
} else {
this.actionQueue_ = null;
}
}
return true;
};
/**
* Called to instruct the element to preconnect to hosts it uses during
* layout.
* @param {boolean} onLayout Whether this was called after a layout.
*/
ElementProto.preconnect = function(onLayout) {
if (onLayout) {
this.implementation_.preconnectCallback(onLayout);
} else {
// If we do early preconnects we delay them a bit. This is kind of
// an unfortunate trade off, but it seems faster, because the DOM
// operations themselves are not free and might delay
timer.delay(() => {
this.implementation_.preconnectCallback(onLayout);
}, 1);
}
};
/**
* @return {!Vsync}
* @private
*/
ElementProto.getVsync_ = function() {
return vsyncFor(this.ownerDocument.defaultView);
};
/**
* Updates the layout box of the element.
* See {@link BaseElement.getLayoutWidth} for details.
* @param {!LayoutRect} layoutBox
*/
ElementProto.updateLayoutBox = function(layoutBox) {
this.layoutWidth_ = layoutBox.width;
if (this.isUpgraded()) {
this.implementation_.layoutWidth_ = this.layoutWidth_;
}
// TODO(malteubl): Forward for stubbed elements.
this.implementation_.onLayoutMeasure();
if (this.isLoadingEnabled_()) {
if (this.isInViewport_) {
// Already in viewport - start showing loading.
this.toggleLoading_(true);
} else if (layoutBox.top < PREPARE_LOADING_THRESHOLD_ &&
layoutBox.top >= 0) {
// Few top elements will also be pre-initialized with a loading
// element.
this.getVsync_().mutate(() => {
this.prepareLoading_();
});
}
}
};
/**
* If the element has a media attribute, evaluates the value as a media
* query and based on the result adds or removes the class
* `-amp-hidden-by-media-query`. The class adds display:none to the element
* which in turn prevents any of the resource loading to happen for the
* element.
*
* This method is called by Resources and shouldn't be called by anyone else.
*
* @final
* @package
*/
ElementProto.applySizesAndMediaQuery = function() {
this.assertNotTemplate_();
// Media query.
if (this.mediaQuery_ === undefined) {
this.mediaQuery_ = this.getAttribute('media') || null;
}
if (this.mediaQuery_) {
this.classList.toggle('-amp-hidden-by-media-query',
!this.ownerDocument.defaultView.matchMedia(this.mediaQuery_).matches);
}
// Sizes.
if (this.sizeList_ === undefined) {
const sizesAttr = this.getAttribute('sizes');
this.sizeList_ = sizesAttr ? parseSizeList(sizesAttr) : null;
}
if (this.sizeList_) {
this.style.width = this.sizeList_.select(this.ownerDocument.defaultView);
}
// Heights.
if (this.heightsList_ === undefined) {
const heightsAttr = this.getAttribute('heights');
this.heightsList_ = heightsAttr ?
parseSizeList(heightsAttr, /* allowPercent */ true) : null;
}
if (this.heightsList_ && this.layout_ ===
Layout.RESPONSIVE && this.sizerElement_) {
this.sizerElement_.style.paddingTop = this.heightsList_.select(
this.ownerDocument.defaultView);
}
};
/**
* Changes the size of the element.
*
* This method is called by Resources and shouldn't be called by anyone else.
* This method must always be called in the mutation context.
*
* @param {number|undefined} newHeight
* @param {number|undefined} newWidth
* @final
* @package
*/
ElementProto./*OK*/changeSize = function(newHeight, newWidth) {
if (this.sizerElement_) {
// From the moment height is changed the element becomes fully
// responsible for managing its height. Aspect ratio is no longer
// preserved.
this.sizerElement_.style.paddingTop = '0';
}
if (newHeight !== undefined) {
this.style.height = newHeight + 'px';
}
if (newWidth !== undefined) {
this.style.width = newWidth + 'px';
}
};
/**
* Called when the element is first attached to the DOM. Calls
* {@link firstAttachedCallback} if this is the first attachment.
* @final
*/
ElementProto.attachedCallback = function() {
if (!TEMPLATE_TAG_SUPPORTED) {
this.isInTemplate_ = !!dom.closestByTag(this, 'template');
}
if (this.isInTemplate_) {
return;
}
if (!this.everAttached) {
this.everAttached = true;
try {
this.firstAttachedCallback_();
} catch (e) {
reportError(e, this);
}
}
this.resources_.add(this);
};
/**
* Called when the element is detached from the DOM.
* @final
*/
ElementProto.detachedCallback = function() {
if (this.isInTemplate_) {
return;
}
this.resources_.remove(this);
};
/**
* Called when the element is attached to the DOM for the first time.
* @private @final
*/
ElementProto.firstAttachedCallback_ = function() {
if (!this.isUpgraded()) {
this.classList.add('amp-unresolved');
this.classList.add('-amp-unresolved');
}
try {
this.layout_ = applyLayout_(this);
if (this.layout_ != Layout.NODISPLAY &&
!this.implementation_.isLayoutSupported(this.layout_)) {
throw new Error('Layout not supported for: ' + this.layout_);
}
this.implementation_.layout_ = this.layout_;
this.implementation_.firstAttachedCallback();
} catch (e) {
reportError(e, this);
throw e;
}
if (!this.isUpgraded()) {
// amp:attached is dispatched from the ElementStub class when it replayed
// the firstAttachedCallback call.
this.dispatchCustomEvent('amp:stubbed');
} else {
this.dispatchCustomEvent('amp:attached');
}
};
/**
* @param {string} name
* @param {!Object=} opt_data Event data.
* @final
*/
ElementProto.dispatchCustomEvent = function(name, opt_data) {
const data = opt_data || {};
// Constructors of events need to come from the correct window. Sigh.
const win = this.ownerDocument.defaultView;
const event = win.document.createEvent('Event');
event.data = data;
event.initEvent(name, true, true);
this.dispatchEvent(event);
};
/**
* Whether the element can pre-render.
* @return {boolean}
* @final
*/
ElementProto.prerenderAllowed = function() {
return this.implementation_.prerenderAllowed();
};
/**
* Whether the element should ever render when it is not in viewport.
* @return {boolean}
* @final
*/
ElementProto.renderOutsideViewport = function() {
return this.implementation_.renderOutsideViewport();
};
/**
* @return {!LayoutRect}
* @final
*/
ElementProto.getLayoutBox = function() {
return this.resources_.getResourceForElement(this).getLayoutBox();
};
/**
* Returns a change entry for that should be compatible with
* IntersectionObserverEntry.
* @return {!IntersectionObserverEntry} A change entry.
* @final
*/
ElementProto.getIntersectionChangeEntry = function() {
const box = this.implementation_.getIntersectionElementLayoutBox();
const rootBounds = this.implementation_.getViewport().getRect();
return getIntersectionChangeEntry(
timer.now(),
rootBounds,
box);
};
/**
* The runtime calls this method to determine if {@link layoutCallback}
* should be called again when layout changes.
* @return {boolean}
* @package @final
*/
ElementProto.isRelayoutNeeded = function() {
return this.implementation_.isRelayoutNeeded();
};
/**
* Instructs the element to layout its content and load its resources if
* necessary by calling the {@link BaseElement.layoutCallback} method that
* should be implemented by BaseElement subclasses. Must return a promise
* that will yield when the layout and associated loadings are complete.
*
* This method is always called for the first layout, but for subsequent
* layouts the runtime consults {@link isRelayoutNeeded} method.
*
* Can only be called on a upgraded and built element.
*
* @return {!Promise}
* @package @final
*/
ElementProto.layoutCallback = function() {
this.assertNotTemplate_();
dev.assert(this.isUpgraded() && this.isBuilt(),
'Must be upgraded and built to receive viewport events');
this.dispatchCustomEvent('amp:load:start');
const promise = this.implementation_.layoutCallback();
this.preconnect(/* onLayout */ true);
this.classList.add('-amp-layout');
return promise.then(() => {
this.readyState = 'complete';
this.layoutCount_++;
this.toggleLoading_(false, /* cleanup */ true);
if (this.layoutCount_ == 1) {
this.implementation_.firstLayoutCompleted();
}
}, reason => {
this.toggleLoading_(false, /* cleanup */ true);
throw reason;
});
};
/**
* Instructs the resource that it entered or exited the visible viewport.
*
* Can only be called on a upgraded and built element.
*
* @param {boolean} inViewport Whether the element has entered or exited
* the visible viewport.
* @final @package
*/
ElementProto.viewportCallback = function(inViewport) {
this.assertNotTemplate_();
this.isInViewport_ = inViewport;
if (this.layoutCount_ == 0) {
if (!inViewport) {
this.toggleLoading_(false);
} else {
// Set a minimum delay in case the element loads very fast or if it
// leaves the viewport.
timer.delay(() => {
if (this.layoutCount_ == 0 && this.isInViewport_) {
this.toggleLoading_(true);
}
}, 100);
}
}
if (this.isUpgraded() && this.isBuilt()) {
this.updateInViewport_(inViewport);
}
};
/**
* @param {boolean} inViewport
* @private
*/
ElementProto.updateInViewport_ = function(inViewport) {
this.implementation_.inViewport_ = inViewport;
this.implementation_.viewportCallback(inViewport);
};
/**
* Requests the resource to stop its activity when the document goes into
* inactive state. The scope is up to the actual component. Among other
* things the active playback of video or audio content must be stopped.
*
* @package @final
*/
ElementProto.pauseCallback = function() {
this.assertNotTemplate_();
if (!this.isBuilt() || !this.isUpgraded()) {
return;
}
this.implementation_.pauseCallback();
};
/**
* Requests the resource to resume its activity when the document returns from
* an inactive state. The scope is up to the actual component. Among other
* things the active playback of video or audio content may be resumed.
*
* @package @final
*/
ElementProto.resumeCallback = function() {
this.assertNotTemplate_();
if (!this.isBuilt() || !this.isUpgraded()) {
return;
}
this.implementation_.resumeCallback();
};
/**
* Requests the element to unload any expensive resources when the element
* goes into non-visible state. The scope is up to the actual component.
*
* Calling this method on unbuilt ot unupgraded element has no effect.
*
* @return {boolean}
* @package @final
*/
ElementProto.unlayoutCallback = function() {
this.assertNotTemplate_();
if (!this.isBuilt() || !this.isUpgraded()) {
return false;
}
return this.implementation_.unlayoutCallback();
};
/**
* Whether to call {@link unlayoutCallback} when pausing the element.
* Certain elements cannot properly pause (like amp-iframes with unknown
* video content), and so we must unlayout to stop playback.
*
* @return {boolean}
* @package @final
*/
ElementProto.unlayoutOnPause = function() {
return this.implementation_.unlayoutOnPause();
};
/**
* Enqueues the action with the element. If element has been upgraded and
* built, the action is dispatched to the implementation right away.
* Otherwise the invocation is enqueued until the implementation is ready
* to receive actions.
* @param {!ActionInvocation} invocation
* @final
*/
ElementProto.enqueAction = function(invocation) {
this.assertNotTemplate_();
if (!this.isBuilt()) {
dev.assert(this.actionQueue_).push(invocation);
} else {
this.executionAction_(invocation, false);
}
};
/**
* Dequeues events from the queue and dispatches them to the implementation
* with "deferred" flag.
* @private
*/
ElementProto.dequeueActions_ = function() {
if (!this.actionQueue_) {
return;
}
const actionQueue = dev.assert(this.actionQueue_);
this.actionQueue_ = null;
// TODO(dvoytenko, #1260): dedupe actions.
actionQueue.forEach(invocation => {
this.executionAction_(invocation, true);
});
};
/**
* Executes the action immediately. All errors are consumed and reported.
* @param {!ActionInvocation} invocation
* @param {boolean} deferred
* @final
* @private
*/
ElementProto.executionAction_ = function(invocation, deferred) {
try {
this.implementation_.executeAction(invocation, deferred);
} catch (e) {
rethrowAsync('Action execution failed:', e,
invocation.target.tagName, invocation.method);
}
};
/**
* Returns the original nodes of the custom element without any service nodes
* that could have been added for markup. These nodes can include Text,
* Comment and other child nodes.
* @return {!Array<!Node>}
* @package @final
*/
ElementProto.getRealChildNodes = function() {
const nodes = [];
for (let n = this.firstChild; n; n = n.nextSibling) {
if (!isInternalOrServiceNode(n)) {
nodes.push(n);
}
}
return nodes;
};
/**
* Returns the original children of the custom element without any service
* nodes that could have been added for markup.
* @return {!Array<!Element>}
* @package @final
*/
ElementProto.getRealChildren = function() {
const elements = [];
for (let i = 0; i < this.children.length; i++) {
const child = this.children[i];
if (!isInternalOrServiceNode(child)) {
elements.push(child);
}
}
return elements;
};
/**
* Returns an optional placeholder element for this custom element.
* @return {?Element}
* @package @final
*/
ElementProto.getPlaceholder = function() {
return dom.childElementByAttr(this, 'placeholder');
};
/**
* Hides or shows the placeholder, if available.
* @param {boolean} state
* @package @final
*/
ElementProto.togglePlaceholder = function(state) {
this.assertNotTemplate_();
const placeholder = this.getPlaceholder();
if (placeholder) {
placeholder.classList.toggle('amp-hidden', !state);
}
};
/**
* Returns an optional fallback element for this custom element.
* @return {?Element}
* @package @final
*/
ElementProto.getFallback = function() {
return dom.childElementByAttr(this, 'fallback');
};
/**
* Hides or shows the fallback, if available. This function must only
* be called inside a mutate context.
* @param {boolean} state
* @package @final
*/
ElementProto.toggleFallback = function(state) {
this.assertNotTemplate_();
// This implementation is notably less efficient then placeholder toggling.
// The reasons for this are: (a) "not supported" is the state of the whole
// element, (b) some realyout is expected and (c) fallback condition would
// be rare.
this.classList.toggle('amp-notsupported', state);
if (state == true) {
const fallbackElement = this.getFallback();
if (fallbackElement) {
this.resources_.scheduleLayout(this, fallbackElement);
}
}
};
/**
* Whether the loading can be shown for this element.
You can’t perform that action at this time.