loadstart ( onloadstart )イベント

　loadstart ( onloadstart )イベントは、<audio>,<video>メディアデータのダウンロードプロセスが始まったら発生するイベントです。

メディアに関するイベント

　<audio>,<video>によるロードプロセスをフォローするイベントには以下があります。

イベントタイプ名	条件
oncanplay	<audio>または<video>メディアの再生が可能になったら
oncanplaythrough	バッファリングを停止することなく再生できる
ondurationchange	メディアの再生時間が変更されたら
onloadedmetadata	メディアのmetaデータが読み込まれたら
onloadeddata	次のフレームが再生できなければ
onpause	メディアの再生を一時停止
onplay	再生される、または一時停止から再開すると
onplaying	一時停止または停止した後に再生を再開すると
onratechange	再生速度が変更されたら
onseeked	再生位置を変更するまたはスキップし再生が始まったら
onseeking	再生位置を変更またはスキップ操作直後

構文（Syntax）

in HTML

<tagelement onloadstart="oneFunction()">

in JavaScript

object.onloadstart = function(){ };

object.addEventListener("loadstart", script_);

備考（Remarks）


Bubbles	No
Cancelable	No
Interface	UiEvent（ユーザーインターフェイスから生成された場合）,Event
Supported HTML Elements	全般

読み込みに関するイベント

　読み込み、 FileReader に関するイベントです。 FileReader は EventTarget が継承しているインターフェイスです。


onabort	読み込みが途中でキャンセルされたら
onerror	リソースの読み込みの失敗または実行時にエラーが発生したら
onload	ページが読み込まれたら。キャッシュからページが読み込まれたこのイベントは発生しません
onloadend	読み込みが終了したら
onloadstart	メディアデータのダウンロードプロセスが始まったら
pagehide	ページが遷移したら。キャッシュされます
pageshow	ページが読み込まれたら。キャッシュの有無に関係なくイベントが発生
onprogress	リクエストが処理されている間
onunload	ページが遷移したら。キャッシュされません

ABC順INDEX

A

Interface: Attr; AnimationEvent
Event: abort; afterprint　未対応ブラウザあり ( Window ); animationend; animationiteration; animationstart
Parameter: activeElement ( DocumentOrShadowRoot ); altKey ( MouseEvent,KeyboardEvent ); animationName ( AnimationEvent ); assignedSlot ( Slotable ); attributes ( Element )
Method: addEventListener() ( EventTarget ); animate() ( Element ); appendChild() ( Node ); attachShadow() ( Element ); atob() ( WindowOrWorkerGlobalScope )

B

Interface
Event: beforeprint　未対応ブラウザあり ( Window ); beforeunload ( Window ); blur
Parameter: baseURI ( Node ); baseURIObject ( Node ); body ( Document ); bubbles ( Event ); button ( MouseEvent ); buttons ( MouseEvent )
Method: btoa() ( WindowOrWorkerGlobalScope )

C

Interface: ClipboardEvent; CSS Object Model
Event: canplay; canplaythrough; change; click; contextmenu; copy; cut
Parameter: cancelable ( Event ); caches ( WindowOrWorkerGlobalScope ); charCode ( KeyboardEvent ); characterSet ( Document ); childNodes ( Node ); classList ( Element ); className ( Element ); clearInterval() ( WindowOrWorkerGlobalScope ); clearTimeout() ( WindowOrWorkerGlobalScope ); clientHeight ( Element ); clientLeft ( Element ); clientTop ( Element ); clientWidth ( Element ); clientX ( MouseEvent ); clientY ( MouseEvent ); closed ( Window ); code ( KeyboardEvent ); computedName ( Element ); computedRole ( Element ); console ( Window ); controllers ( Window ); cookie ( Document ); ctrlKey ( MouseEvent,KeyboardEvent ); currentTarget ( Event )
Method: cloneNode() ( Node ); closest() ( Element ); computedStyleMap() ( Element ); compareDocumentPosition() ( Node ); contains() ( Node ); createEvent(); crypto ( Window ); createImageBitmap() ( WindowOrWorkerGlobalScope ); createShadowRoot() ( Element ); customElements ( Window )

D

Interface: Document; DragEvent
Event: dblclick; devicemotion ( Window ); deviceorientation ( Window ); drag; dragend; dragenter; dragleave; dragover; dragstart; drop; durationchange
Parameter: data ( InputEvent ); defaultPrevented ( Event ); defaultView ( Document ); deltaMode ( WheelEvent ); deltaX ( WheelEvent ); deltaY ( WheelEvent ); deltaZ ( WheelEvent ); designMode ( Document ); detail ( UiEvent ); devicePixelRatio ( Window ); dialogArguments ( Window ); dir ( Document ); doctype ( Document ); document ( Window ); documentElement ( Document ); documentURI ( Document ); domain ( Document ); DOMMatrix ( Window ); DOMMatrixReadOnly ( Window ); DOMPoint ( Window ); DOMPointReadOnly ( Window ); DOMQuad ( Window ); DOMRect ( Window ); DOMRectReadOnly ( Window )
Method: dispatchEvent() ( EventTarget )

E

Interface: Element; EventTarget; Event
Event: emptied; ended; error
Parameter: elapsedTime ( AnimationEvent,TransitionEvent ); embeds ( Document ); event ( Window ); eventPhase ( Event )
Method: entries() ( NodeList )

F

Interface: FocusEvent
Event: focus; focusin; focusout; fullscreenchange; fullscreenerror
Parameter: featurePolicy ( Document ); firstChild ( Node ); fonts ( Document ); forms ( Document ); frameElement ( Window ); frames ( Window ); fullScreen ( Window ); fullscreenElement ( DocumentOrShadowRoot )
Method: fetch() ( WindowOrWorkerGlobalScope ); forEach() ( NodeList )

G

Interface: GamepadEvent
Event: gamepadconnected ( Window ); gamepaddisconnected ( Window )
Parameter
Method: getAnimations() ( Element ); getAttribute() ( Element ); getAttributeNames() ( Element ); getAttributeNS() ( Element ); getAttributeNode() ( Element ); getAttributeNodeNS() ( Element ); getBoundingClientRect() ( Element ); getClientRects() ( Element ); getElementsByClassName() (Document, Element); getElementById() (Document); getElementsByName() (Document, Element); getElementsByTagName() (Document, Element); getElementsByTagNameNS() (Document, Element); getModifierState() ( Event ); getRootNode() ( Node )

H

Interface: HashChangeEvent; HTMLFieldSetElement; HTMLFormElement; HTMLAnchorElement; HTMLAreaElement; HTMLAudioElement; HTMLBaseElement; HTMLBaseFontElement (en-US); HTMLBodyElement; HTMLBRElement; HTMLButtonElement; HTMLCanvasElement; HTMLCollection; HTMLContentElement; HTMLDataElement; HTMLDataListElement (en-US); HTMLDetailsElement; HTMLDialogElement; HTMLDivElement; HTMLDListElement; HTMLDocument; HTMLElement; HTMLEmbedElement; HTMLFieldSetElement; HTMLFontElement (en-US); HTMLFormControlsCollection; HTMLFormElement; HTMLFrameSetElement (en-US); HTMLHeadElement; HTMLHeadingElement; HTMLHRElement; HTMLHtmlElement; HTMLIFrameElement; HTMLImageElement (en-US); HTMLInputElement; HTMLKeygenElement; HTMLLabelElement; HTMLLegendElement; HTMLLIElement; HTMLLinkElement; HTMLMapElement; HTMLMarqueeElement (en-US); HTMLMediaElement; HTMLMenuElement (en-US); HTMLMenuItemElement (en-US); HTMLMetaElement; HTMLMeterElement (en-US); HTMLModElement; HTMLObjectElement; HTMLOListElement; HTMLOptGroupElement (en-US); HTMLOptionElement; HTMLOptionsCollection (en-US); HTMLOutputElement; HTMLParagraphElement; HTMLParamElement; HTMLPictureElement; HTMLPreElement (en-US); HTMLProgressElement (en-US); HTMLQuoteElement; HTMLScriptElement; HTMLSelectElement; HTMLShadowElement; HTMLSlotElement; HTMLSourceElement; HTMLSpanElement; HTMLStyleElement; HTMLTableCaptionElement (en-US); HTMLTableCellElement (en-US); HTMLTableColElement; HTMLTableElement; HTMLTableRowElement; HTMLTableSectionElement (en-US); HTMLTemplateElement; HTMLTextAreaElement; HTMLTimeElement; HTMLTitleElement; HTMLTrackElement (en-US); HTMLUListElement (en-US); HTMLUnknownElement; HTMLVideoElement
Event: hashchange ( Window )
Parameter: head ( Document ); hidden ( Document ); history ( Window )
Method: hasAttribute() ( Element ); hasAttributeNS() ( Element ); hasAttributes() ( Element ); hasChildNodes() ( Node ); hasPointerCapture() ( Element )

I

Interface: InputEvent
Event: input; invalid
Parameter: id ( Element ); images ( Document ); implementation ( Document ); indexedDB ( WindowOrWorkerGlobalScope ); innerHeight ( Window ); innerHTML ( Element ); innerWidth ( Window ); inputType ( InputEvent ); isConnected( Node ); isSecureContext ( Window ); isSecureContext ( WindowOrWorkerGlobalScope ); isTrusted ( Event )
Method: insertAdjacentElement() ( Element ); insertAdjacentHTML() ( Element ); insertAdjacentText() ( Element ); insertBefore() ( Node ); item() ( NodeList ); isDefaultNamespace() ( Node ); isEqualNode() ( Node ); isSameNode() ( Node )

J

K

Interface: KeyboardEvent
Event: keydown; keypress; keyup
Parameter: key ( KeyboardEvent ); keyCode( KeyboardEvent )
Method: keys() ( NodeList )

L

Interface: Location
Event: languagechange ( Window ); load; loadeddata; loadedmetadata; loadstart
Parameter: lastChild ( Node ); lastModified ( Document ); lastStyleSheetSet ( Document ); length ( NodeList ); length ( Window ); links ( Document ); localName ( Element ); localname ( Attr ); localStorage ( Window ); location ( Document ); location ( KeyboardEvent ); location ( Window ); locationbar ( Window )
Method: lookupPrefix() ( Node ); lookupNamespaceURI() ( Node )

M

Interface: MouseEvent
Event: message ( Window ); mousedown; mouseenter; mouseleave; mousemove; mouseout; mouseover; mouseup
Parameter: menubar ( Window ); messageManager ( Window ); mozInnerScreenX ( Window ); mozInnerScreenY ( Window ); metaKey ( MouseEvent,KeyboardEvent ); mozSyntheticDocument ( Document )
Method: matches() ( Element )

N

Interface: Node; NodeList
Event
Parameter: name ( Attr ); name ( Window ); namespaceURI ( Attr ); namespaceURI ( Element ); navigator ( Window ); nextElementSibling ( NonDocumentTypeChildNode ); nextSibling ( Node ); newURL ( HashChangeEvent ); nodeName ( Node ); nodePrincipal ( Node ); nodeType ( Node ); nodeValue ( Node )
Method: normalize() ( Node )

O

Interface: OfflineAudioCompletionEvent
Event: offline　未対応のブラウザあり ( Window ); online　未対応のブラウザあり ( Window ); open
Parameter: oldURL ( HashChangeEvent ); outerHTML ( Element ); opener ( Window ); openOrClosedShadowRoot ( Element ); origin ( WindowOrWorkerGlobalScope ); outerHeight ( Window ); outerWidth ( Window ); ownerElement ( Attr ); ownerDocument ( Node )

P

Interface: PageTransitionEvent; PopStateEvent; ProgressEvent
Event: pagehide ( Window ); pageshow ( Window ); paste; pause; play; playing; plugins ( Document ); onpopstate ( Window ); preferredStyleSheetSet ( Document ); progress
Parameter: pageX ( MouseEvent ); pageY ( MouseEvent ); pageXOffset ( Window ); pageYOffset ( Window ); parent ( Window ); parentNode ( Node ); parentElement ( Node ); part ( Element ); performance ( Window ); personalbar ( Window ); prefix ( Attr ); prefix ( Element ); previousElementSibling ( NonDocumentTypeChildNode ); pointerLockElement ( DocumentOrShadowRoot ); previousSibling ( Node ); persisted ( PageTransitionEvent ); propertyName ( TransitionEvent )
Method: pseudo() ( Element ); preventDefault() ( Event )

Q

Method: querySelector() ( Element ); querySelectorAll() ( Element )

R

Interface
Event: readystatechange ( Document ); ratechange; reset; resize
Parameter: readyState ( Document ); referrer ( Document ); relatedTarget ( MouseEvent、FocusEvent )
Method: releasePointerCapture() ( Element ); remove() ( ChildNode ); removeAttribute() ( Element ); removeAttributeNS() ( Element ); removeAttributeNode() ( Element ); removeChild() ( Node ); removeEventListener() ( EventTarget ); replaceChild() ( Node ); requestFullscreen() ( Element ); requestPointerLock() ( Element )

S

Interface: StorageEvent
Event: scroll; search; seeked; seeking; select; show　未対応のブラウザあり; stalled; storage ( Window ); submit; suspend
Parameter: screen ( Window ); screenLeft ( Window ); screenTop ( Window ); screenX ( MouseEvent ); screenX ( Window ); screenY ( MouseEvent ); screenY ( Window ); scripts ( Document ); scrollbars ( Window ); scrollMaxX ( Window ); scrollMaxY ( Window ); scrollX ( Window ); scrollY ( Window ); scrollingElement ( Document ); scrollHeight ( Element ); scrollLeft ( Element ); scrollLeftMax ( Element ); scrollTop ( Element ); scrollTopMax ( Element ); scrollWidth ( Element ); selectedStyleSheetSet ( Document ); self ( Window ); sessionStorage ( Window ); shadowRoot ( Element ); shiftKey ( MouseEvent, KeyboardEvent ); sidebar ( Window ); slot ( Element ); styleSheets ( DocumentOrShadowRoot ); styleSheetSets ( Document )
Method: scroll() ( Element ); scrollBy() ( Element ); scrollIntoView() ( Element ); scrollTo() ( Element ); setAttribute() ( Element ); setAttributeNS() ( Element ); setAttributeNode() ( Element ); setAttributeNodeNS() ( Element ); setCapture() ( Element ); setInterval() ( WindowOrWorkerGlobalScope ); setPointerCapture() ( Element ); setTimeout() ( WindowOrWorkerGlobalScope ); specified ( Attr ); speechSynthesis ( Window ); status ( Window ); statusbar ( Window ); stopImmediatePropagation() ( Event ); stopPropagation() ( Event )

T

Interface: TouchEvent
Event: timeupdate; toggle; touchcancel; touchend; touchmove; touchstart; transitionend
Parameter: tabStop ( Element ); tagName ( Element ); target ( Event ); targetTouches ( Event ); textContent ( Node ); timeline ( Document ); timeStamp ( Event ); title ( Document ); toolbar ( Window ); top ( Window ); touches ( Event ); transitionend ( Event ); type ( Event )
Method: toggleAttribute() ( Element ); toLocaleString() ( prototype )

U

Interface: UiEvent
Event: unhandledrejection ( Window ); unload ( Window )
Parameter: undoManager ( Element ); undoScope ( Element ); URL ( Document )

V

Interface
Event: visibilitychange ( Document ); volumechange
Parameter: visualViewport ( Window ); view ( Event ); visibilityState ( Document )
Method: value ( Attr ); values() ( NodeList )