HTML

Living Standard — Last Updated 14 July 2020

1. 1. 1. 4.8.5 iframe要素
      2. 4.8.6 embed要素
      3. 4.8.7 object要素
      4. 4.8.8 param要素

4.8.5 iframe要素

カテゴリー：

フローコンテンツ。

フレージングコンテンツ。

エンベディッドコンテンツ。

インタラクティブコンテンツ。

パルパブルコンテンツ。

この要素を使用できるコンテキスト：

エンベディッドコンテンツが期待される場所。

コンテンツモデル：

Nothing。

text/htmlにおけるタグ省略：

どちらのタグも省略不可。

コンテンツ属性：

グローバル属性

src — リソースのアドレス

srcdoc — iframe内でレンダリングする文書

name — ネストされたブラウジングコンテキスト名

sandbox — ネストされたコンテンツのセキュリティールール

allow — iframeのコンテンツに適用されるPermissions policy

allowfullscreen — iframeのコンテンツにrequestFullscreen()の使用を許可するかどうか

allowpaymentrequest — iframeのコンテンツがPaymentRequestインターフェイスを使用して支払い要求を行うことが許可されているかどうか

width — 横の次元

height — 縦の次元

referrerpolicy — 要素によって開始されたフェッチのためのリファラポリシー

loading — 読み込み延期を決定するときに使用

アクセシビリティの考慮：

著者向け。

実装者向け。

DOMインターフェイス：

[Exposed=Window]
interface HTMLIFrameElement : HTMLElement {
  [HTMLConstructor] constructor();

  [CEReactions] attribute USVString src;
  [CEReactions] attribute DOMString srcdoc;
  [CEReactions] attribute DOMString name;
  [SameObject, PutForwards=value] readonly attribute DOMTokenList sandbox;
  [CEReactions] attribute DOMString allow;
  [CEReactions] attribute boolean allowFullscreen;
  [CEReactions] attribute boolean allowPaymentRequest;
  [CEReactions] attribute DOMString width;
  [CEReactions] attribute DOMString height;
  [CEReactions] attribute DOMString referrerPolicy;
  [CEReactions] attribute DOMString loading;
  readonly attribute Document? contentDocument;
  readonly attribute WindowProxy? contentWindow;
  Document? getSVGDocument();

  // also has obsolete members
};

iframe要素は、そのネストされたブラウジングコンテキストを表す。

src属性は、その要素のネストされたブラウジングコンテキストが含まれるページのURLを与える。属性が存在する場合、潜在的にスペースで囲まれた妥当な空でないURLでなければならない。itemprop属性がiframe要素で指定される場合、srcも指定されなければならない。

srcdoc属性は、その要素のネストされたブラウジングコンテキストが含まれるページのコンテンツを与える。属性の値は、iframe srcdoc文書のソースである。

srcdoc属性が存在する場合、指定された順序で、次の構文上のコンポーネントを構成するHTML構文を使用した値を持たなければならない：

1. 任意の数のコメントおよびASCII空白文字。
2. 任意で、DOCTYPE。
3. 任意の数のコメントおよびASCII空白文字。
4. html要素の形式で、文書要素。
5. 任意の数のコメントおよびASCII空白文字。

上記の要件は、同様にXML文書で当てはまる。

<article>
 <h1>I got my own magazine!</h1>
 <p>After much effort, I've finally found a publisher, and so now I
 have my own magazine!Isn't that awesome?!The first issue will come
 out in September, and we have articles about getting food, and about
 getting in boxes, it's going to be great!</p>
 <footer>
  <p>Written by <a href="/users/cap">cap</a>, 1 hour ago.
 </footer>
 <article>
  <footer> Thirteen minutes ago, <a href="/users/ch">ch</a> wrote: </footer>
  <iframe sandbox srcdoc="<p>did you get a cover picture yet?"></iframe>
 </article>
 <article>
  <footer> Nine minutes ago, <a href="/users/cap">cap</a> wrote: </footer>
  <iframe sandbox srcdoc="<p>Yeah, you can see it <a href=&quot;/gallery?mode=cover&amp;amp;page=1&quot;>in my gallery</a>."></iframe>
 </article>
 <article>
  <footer> Five minutes ago, <a href="/users/ch">ch</a> wrote: </footer>
  <iframe sandbox srcdoc="<p>hey that's earl's table.
<p>you should get earl&amp;amp;me on the next cover."></iframe>
 </article>

HTML構文において、著者は属性の内容を包むためにU+0022 QUOTATION MARK文字（"）を使用することを単に覚えておく必要があり、それからすべてのU+0026 AMPERSAND（&）およびU+0022 QUOTATION MARK（"）文字をエスケープし、そしてsandbox属性を指定し、コンテンツの安全な埋め込みを確実にする必要がある。（さらに"ではなく"になるよう、引用符を確実にするために、引用符の前にアンパサンドをエスケープすることを忘れないこと。）

XMLでU+003C LESS-THAN SIGN（<）文字も同様にエスケープする必要がある。属性値正規化を防ぐために、一部のXMLの空白文字―具体的にはU+0009 CHARACTER TABULATION（tab）、U+000A LINE FEED（LF）、U+000D CARRIAGE RETURN（CR）―もまたエスケープする必要がある。[XML]

src属性とsrcdoc属性が両方ともに指定される場合、srcdoc属性が優先される。これは、著者にsrcdoc属性をサポートしないレガシーユーザーエージェントに対してフォールバックURLを提供できる。

When an iframe element element is inserted into a document whose browsing context is non-null, the user agent must run these steps:

1. Create a new nested browsing context for element.

2. Process the iframe attributes for the "first time".

When an iframe element is removed from a document, the user agent must discard the element's nested browsing context, if it is not null, and then set the element's nested browsing context to null.

This happens without any unload events firing (the element's nested browsing context and its Document are discarded, not unloaded).

Whenever an iframe element with a non-null nested browsing context has its srcdoc attribute set, changed, or removed, the user agent must process the iframe attributes.

Similarly, whenever an iframe element with a non-null nested browsing context but with no srcdoc attribute specified has its src attribute set, changed, or removed, the user agent must process the iframe attributes.

When the user agent is to process the iframe attributes, it must run the first appropriate steps from the following list:

If the srcdoc attribute is specified

1. Set the iframe's current navigation was lazy loaded boolean to false.

2. If the will lazy load element steps given the iframe element return true, then:

   1. Set the iframe's lazy load resumption steps to the rest of this algorithm starting with the step labeled navigate to the srcdoc resource.

   2. Set the iframe's current navigation was lazy loaded boolean to true.

   3. Start intersection-observing a lazy loading element for the iframe element.

   4. Return.

3. Navigate to the srcdoc resource: Navigate the element's nested browsing context to a new response whose url list consists of about:srcdoc, header list consists of `Content-Type`/`text/html`, body is the value of the attribute, CSP list is a clone of the iframe element's node document's CSP list, HTTPS state is the HTTPS state of the iframe element's node document.

   The resulting Document must be considered an iframe srcdoc document.

Otherwise, if the element has no src attribute specified, and the user agent is processing the iframe's attributes for the "first time"

Queue an element task on the DOM manipulation task source given the iframe element and the iframe load event steps.

そうでなければ

Run the otherwise steps for iframe or frame elements.

The otherwise steps for iframe or frame elements are as follows:

1. If the element has no src attribute specified, or its value is the empty string, let url be the URL "about:blank".

   Otherwise, parse the value of the src attribute, relative to the element's node document.

   If that is not successful, then let url be the URL "about:blank". Otherwise, let url be the resulting URL record.

2. If there exists an ancestor browsing context whose active document's URL, ignoring fragments, is equal to url, then return.

3. Let resource be a new request whose url is url and whose referrer policy is the current state of the element's referrerpolicy content attribute.

4. Set the iframe's current navigation was lazy loaded boolean to false.

5. If the element is an iframe element, and the will lazy load element steps given the element return true, then:

   1. Set the iframe's lazy load resumption steps to the rest of this algorithm starting with the step labeled navigate to the resource.

   2. Set the iframe's current navigation was lazy loaded boolean to true.

   3. Start intersection-observing a lazy loading element for the iframe element.

   4. Return.

6. Navigate to the resource: Navigate the element's nested browsing context to resource.

Any navigation required of the user agent in the process the iframe attributes algorithm must use the iframe element's node document's browsing context as the source browsing context.

Furthermore, if the active document of the element's nested browsing context before such a navigation was not completely loaded at the time of the new navigation, then the navigation must be completed with replacement enabled.

Similarly, if the element's nested browsing context's session history contained only one Document when the process the iframe attributes algorithm was invoked, and that was the about:blank Document created when the element's nested browsing context was created, then any navigation required of the user agent in that algorithm must be completed with replacement enabled.

When a Document in an iframe is marked as completely loaded, the user agent must run the iframe load event steps.

A load event is also fired at the iframe element when it is created if no other data is loaded in it.

Each Document has an iframe load in progress flag and a mute iframe load flag. When a Document is created, these flags must be unset for that Document.

The iframe load event steps are as follows:

1. Let child document be the active document of the iframe element's nested browsing context (which cannot be null at this point).

2. If child document has its mute iframe load flag set, return.

3. Set child document's iframe load in progress flag.

4. Fire an event named load at the iframe element.

5. Unset child document's iframe load in progress flag.

This, in conjunction with scripting, can be used to probe the URL space of the local network's HTTP servers. User agents may implement cross-origin access control policies that are stricter than those described above to mitigate this attack, but unfortunately such policies are typically not compatible with existing web content.

If an element type potentially delays the load event, then for each element element of that type, the user agent must delay the load event of element's node document if element's nested browsing context is non-null and any of the following are true:

• element's nested browsing context's active document is not ready for post-load tasks.

• Anything is delaying the load event of element's nested browsing context's active document.

• element's nested browsing context is in the delaying load events mode.

If, during the handling of the load event, element's nested browsing context is again navigated, that will further delay the load event.

Each iframe element has an associated current navigation was lazy loaded boolean, initially false. It is set and unset in the process the iframe attributes algorithm.

An iframe element whose current navigation was lazy loaded boolean is false potentially delays the load event.

要素が作成される際、srcdoc属性が設定されず、src属性が設定されてない、または設定されるがその値が解析することができないのいずれかの場合、ブラウジングコンテキストは初期のabout:blankページのままになる。

ユーザーがこのページからナビゲートする場合、iframeのネストされたブラウジングコンテキストのWindowProxyオブジェクトは、新規Documentオブジェクトに対する新規Windowオブジェクトをプロキシサーバーに送るが、src属性は変更されないだろう。

name属性が存在する場合、妥当なブラウジングコンテキスト名でなければならない。指定された値は、要素のネストされたブラウジングコンテキストが作成されたときに存在する場合、その名前を付けるために使用される。

sandbox属性が指定された場合、iframeによってホストされるあらゆるコンテンツに一連の追加の制限が可能になる。その値は、ASCII大文字・小文字不区別である順不同なユニークなスペース区切りのトークンのセットでなければならない。許可される値は、allow-forms、allow-modals、allow-orientation-lock、allow-pointer-lock、allow-popups、allow-popups-to-escape-sandbox、allow-presentation、allow-same-origin、allow-scripts、allow-top-navigation、allow-top-navigation-by-user-activation、allow-downloadsである。

この属性が設定される場合、コンテンツは一意な生成元からのものとして扱われ、フォームやスクリプトは無効となり、リンクは他のブラウジングコンテキストをターゲットすることを防ぎ、プラグインは保護される。allow-same-originキーワードは、コンテンツにユニークな生成元を強制する代わりに、コンテンツを実際の生成元からのものとして扱わさせる。allow-top-navigationキーワードは、コンテンツにトップレベルのブラウジングコンテキストをナビゲートすることができる。allow-top-by-user-activationキーワードは同様に動作するが、ブラウジングコンテキストのアクティブウィンドウがtransient activationを持つ場合にのみそのようなナビゲーションを許可する。allow-forms、allow-modals、allow-orientation-lock、allow-pointer-lock、allow-popups、allow-presentation、allow-scripts、allow-popups-to-escape-sandboxキーワードは、フォーム、モーダルダイアログ、スクリーンの向きのロック、ポインターロックAPI、ポップアップ、プレゼンテーションAPI、スクリプトおよびサンドボックス化されない補助ブラウジングコンテキストの作成をそれぞれ再有効にする。[POINTERLOCK] [SCREENORIENTATION] [PRESENTATION]

allow-top-navigationおよびallow-top-navigation-by-user-activationキーワードは、重複するため、両方指定されてはならない。そのような不適合マークアップにおいて、allow-top-navigationのみが効果を持つ。

効果的に完全にサンドボックスを破壊する、iframeを含むページが埋め込まれたページに簡単にsandbox属性を削除して再読み込みできるので、埋め込まれたページが同一生成元を持つ際に、allow-scriptsおよびallow-same-originの両方のキーワードを共に設定する。

iframe要素のネストされたブラウジングコンテキストがナビゲートされるとき、これらのフラグは効果のみを取る。それらを削除する、または全体のsandbox属性を削除することは、すでに読み込まれたページに影響を与えない。

潜在的に敵対的なファイルは、iframe要素を含むファイルと同じサーバーから提供されるべきではない。攻撃者がiframe内よりむしろ、直接敵対コンテンツを単に訪問することをユーザーに納得させることができる場合、敵対コンテンツをサンドボックス化することは、最小限の助けとなる。敵対的なHTMLコンテンツが原因で発生する可能性のある損害を制限するために、それは独立した専用ドメインから提供されるべきである。たとえsandbox属性の保護なしで、ユーザーが直接そのページを訪れるようだます場合でも、別のドメインを使用することは、ファイル内のスクリプトがサイトを攻撃できないことを保証する。

When an iframe element with a sandbox attribute has its nested browsing context created (before the initial about:blank Document is created), and when an iframe element's sandbox attribute is set or changed while it has a nested browsing context, the user agent must parse the sandboxing directive using the attribute's value as the input and the iframe element's iframe sandboxing flag set as the output.

When an iframe element's sandbox attribute is removed while it has a non-null nested browsing context, the user agent must empty the iframe element's iframe sandboxing flag set.

<p>We're not scared of you! Here is your content, unedited:</p>
<iframe sandbox src="https://usercontent.example.net/getusercontent.cgi?id=12193"></iframe>

<iframe sandbox="allow-same-origin allow-forms allow-scripts"
        src="https://maps.example.com/embedded.html"></iframe>

<iframe sandbox="allow-same-origin allow-forms" src=B></iframe>

<iframe sandbox="allow-scripts" src=C></iframe>

<a href=D>Link</a>

allow属性は、指定された場合、iframeのネストされたブラウジングコンテキスト内のDocumentに対するpermissions policyが初期化されるときに使用されるコンテナポリシーを決定する。その値はserialized permissions policyでなければならない。[PERMISSIONSPOLICY]

<iframe src="https://maps.example.com/" allow="geolocation"></iframe>

allowfullscreen属性は、真偽属性である。指定する場合、iframe要素のネストされたブラウジングコンテキスト内のDocumentオブジェクトは、任意の生成元から"fullscreen"機能を使用できるようにするpermissions policyで初期化されることを示す。これは、process permissions policy attributesアルゴリズムによって実施される。[PERMISSIONSPOLICY]

<article>
 <header>
  <p><img src="/usericons/1627591962735"> <b>Fred Flintstone</b></p>
  <p><a href="/posts/3095182851" rel=bookmark>12:44</a> — <a href="#acl-3095182851">Private Post</a></p>
 </header>
 <p>Check out my new ride!</p>
 <iframe src="https://video.example.com/embed?id=92469812" allowfullscreen></iframe>
</article>

allowpaymentrequest属性は、真偽属性である。指定する場合、iframe要素のネストされたブラウジングコンテキスト内のDocumentオブジェクトは、任意の生成元から"payment"機能を使用できるようにするpermissions policyで初期化されることを示す。これは、Process permissions policy attributesアルゴリズムによって実施される。[PERMISSIONSPOLICY]

allow、allowfullscreenまたはallowpaymentrequestのいずれの属性も、iframe要素のノード文書にその機能の使用が許可されない場合、その要素のネストされたブラウジングコンテキストで機能にアクセスを許可することができない。

To determine whether a Document object document is allowed to use the policy-controlled-feature feature, run these steps:

1. If document's browsing context is null, then return false.

2. If document's browsing context's active document is not document, then return false.

3. If the result of running is feature enabled in document for origin on feature, document, and document's origin is "Enabled", then return true.

4. Return false.

ネストされたブラウジングコンテキストのアクティブ文書のpermissions policyにのみ影響するため、allow、allowfullscreenおよびallowpaymentrequest属性は、iframeのネストされたブラウジングコンテキストがナビゲートされるときにのみ有効である。それらを追加または削除しても、すでに読み込まれている文書には影響しない。

iframe要素は、埋め込まれたコンテンツが特定のサイズをもつ（たとえば単位が明確に定義された次元をもつ）場合、次元属性をサポートする。

指定した初期コンテンツ内容が正常に使用されるかどうかに関わらず、常にネストしたブラウジングコンテキストを作成するので、iframe要素はフォールバックコンテンツにならない。

referrerpolicy属性は、リファラポリシー属性である。その目的は、iframe属性を処理する際に使用されるリファラポリシーを設定することにある。[REFERRERPOLICY]

loading属性は、遅延読み込み属性である。その目的は、ビューポート外にあるiframeを読み込むためのポリシーを示すことである。

When the loading attribute's state is changed to the Eager state, the user agent must run these steps:

1. Let resumptionSteps be the iframe element's lazy load resumption steps.

2. If resumptionSteps is null, then return.

3. Set the iframe's lazy load resumption steps to null.

4. Invoke resumptionSteps.

iframe要素の子孫は何も表さない。（iframe要素をサポートしないレガシーユーザーエージェントにおいて、コンテンツはフォールバックコンテンツとして機能することができるマークアップとして解析される。）

HTMLパーサーは、テキストとしてiframe要素の内側のマークアップを扱う。

The IDL attributes src, srcdoc, name, sandbox, and allow must reflect the respective content attributes of the same name.

The supported tokens for sandbox's DOMTokenList are the allowed values defined in the sandbox attribute and supported by the user agent.

The allowFullscreen IDL attribute must reflect the allowfullscreen content attribute.

The allowPaymentRequest IDL attribute must reflect the allowpaymentrequest content attribute.

The referrerPolicy IDL attribute must reflect the referrerpolicy content attribute, limited to only known values.

The loading IDL attribute must reflect the loading content attribute, limited to only known values.

The contentDocument IDL attribute, on getting, must return the iframe element's content document.

The contentWindow IDL attribute must return the WindowProxy object of the iframe element's nested browsing context, if its nested browsing context is non-null, or null otherwise.

<iframe src="https://ads.example.com/?customerid=923513721&amp;format=banner"
        width="468" height="60"></iframe>

4.8.6 embed要素

カテゴリー：

フローコンテンツ。

フレージングコンテンツ。

エンベディッドコンテンツ。

インタラクティブコンテンツ。

パルパブルコンテンツ。

この要素を使用できるコンテキスト：

エンベディッドコンテンツが期待される場所。

コンテンツモデル：

Nothing。

text/htmlにおけるタグ省略：

終了タグなし。

コンテンツ属性：

グローバル属性

src — リソースのアドレス

type — 埋め込みリソースタイプ

width — 横の次元

height — 縦の次元

名前空間を持たないその他の属性（文参照）。

アクセシビリティの考慮：

著者向け。

実装者向け。

DOMインターフェイス：

[Exposed=Window]
interface HTMLEmbedElement : HTMLElement {
  [HTMLConstructor] constructor();

  [CEReactions] attribute USVString src;
  [CEReactions] attribute DOMString type;
  [CEReactions] attribute DOMString width;
  [CEReactions] attribute DOMString height;
  Document? getSVGDocument();

  // also has obsolete members
};

Depending on the type of content instantiated by the embed element, the node may also support other interfaces.

embed要素は外部の（典型的には非HTML）アプリケーションやインタラクティブコンテンツの統合点を提供する。

src属性は、埋め込まれているリソースのURLを与える。属性が存在する場合、潜在的にスペースで囲まれた妥当な空でないURLを含まなければならない。

著者は、信頼できないリソースの参照を避けるべきである。そのようなリソースは、著者がFlashの"allowScriptAccess"パラメーターなどの機能を使用した場合でも、プラグインのインスタンス化やスクリプトの実行に使用できる。

itempropがembed要素で指定される場合、src属性も指定されなければならない。

type属性が存在する場合は、インスタンスを生成するプラグインが選択されるMIMEタイプを提供する。値は妥当なMIMEタイプ文字列でなければならない。type属性とsrc属性の両方が存在する場合、type属性は、src属性で指定されたリソースの明示的なContent-Typeメタデータと同じ型を指定しなければならない。

While any of the following conditions are occurring, any plugin instantiated for the element must be removed, and the embed element represents nothing:

• The element has neither a src attribute nor a type attribute.

• The element has a media element ancestor.

• The element has an ancestor object element that is not showing its fallback content.

An embed element is said to be potentially active when the following conditions are all met simultaneously:

• The element is in a document or was in a document the last time the event loop reached step 1.
• The element's node document is fully active.
• The element has either a src attribute set or a type attribute set (or both).
• The element's src attribute is either absent or its value is not the empty string.
• The element is not a descendant of a media element.
• The element is not a descendant of an object element that is not showing its fallback content.
• The element is being rendered, or was being rendered the last time the event loop reached step 1.

Whenever an embed element that was not potentially active becomes potentially active, and whenever a potentially active embed element that is remaining potentially active and has its src attribute set, changed, or removed or its type attribute set, changed, or removed, the user agent must queue an element task on the embed task source given the element to run the embed element setup steps for that element.

The embed element setup steps for a given embed element element are as follows:

1. If another task has since been queued to run the embed element setup steps for element, then return.

2. If the Should element be blocked a priori by Content Security Policy? algorithm returns "Blocked" when executed on element, then return. [CSP]

3. If element has a src attribute set, then:

   1. Let url be the result of parsing the value of element's src attribute, relative to element's node document.

   2. If url is failure, then return.

   3. Let request be a new request whose url is url, client is element's node document's relevant settings object, destination is "embed", credentials mode is "include", mode is "navigate", and whose use-URL-credentials flag is set.

   4. Fetch request.

      Fetching the resource must delay the load event of element's node document.

      To process response for the response response:

      1. If another task has since been queued to run the embed element setup steps for element, then return.

      2. Let type be the result of determining the type of content given element and response.

      3. Switch on type:

         null

         1. Display no plugin for element.

         image/svg+xml

         1. If element's nested browsing context is null, then create a new nested browsing context for element.

         2. Navigate element's nested browsing context to response, with replacement enabled, and with element's node document's browsing context as the source browsing context.

            element's src attribute does not get updated if the browsing context gets further navigated to other locations.

         3. element now represents its nested browsing context.

         4. When the Document of element's nested browsing context is marked as completely loaded, queue an element task on the DOM manipulation task source given element to fire an event named load at element.

         そうでなければ

         1. Display a plugin for element, given type and response.

4. Otherwise:

   1. Let type be the value of element's type attribute.

   2. If type is a type that a plugin supports, then display a plugin for element given type.

   3. Otherwise, display no plugin for element.

To determine the type of the content given an embed element element and a response response, run the following steps:

1. If element has a type attribute, and that attribute's value is a type that a plugin supports, then return the value of the type attribute.

2. If the path component of response's url matches a pattern that a plugin supports, then return the type that that plugin can handle.

   For example, a plugin might say that it can handle URLs with path components that end with the four character string ".swf".

3. If response has explicit Content-Type metadata, and that value is a type that a plugin supports, then return that value.

4. Return null.

It is intentional that the above algorithm allows response to be a network error or to have a non-ok status. This allows servers to return data for plugins even with error responses (e.g., HTTP 500 Internal Server Error codes can still contain plugin data).

To display a plugin for an embed element element, given a string type and optionally a response response:

1. If element's nested browsing context is not null, then:

   1. Discard element's nested browsing context.

   2. Set element's nested browsing context to null.

2. Find and instantiate an appropriate plugin based on type, replacing any previously-instantiated plugin for element. If response was given, forward it to the plugin.

3. element now represents this plugin instance.

4. Once the plugin, and response if given, are completely loaded, queue an element task on the DOM manipulation task source give element to fire an event named load at element.

To display no plugin for an embed element element:

1. If element's nested browsing context is not null, then:

   1. Discard element's nested browsing context.

   2. Set element's nested browsing context to null.

2. Display an indication that no plugin could be found for element, replacing any previously-instantiated plugin for element.

3. element now represents nothing.

The embed element has no fallback content; its descendants are ignored.

Whenever an embed element that was potentially active stops being potentially active, any plugin that had been instantiated for that element must be unloaded.

When a plugin is to be instantiated but it cannot be secured and the sandboxed plugins browsing context flag is set on the embed element's node document's active sandboxing flag set, then the user agent must not instantiate the plugin, and must instead render the embed element in a manner that conveys that the plugin was disabled. The user agent may offer the user the option to override the sandbox and instantiate the plugin anyway; if the user invokes such an option, the user agent must act as if the conditions above did not apply for the purposes of this element.

Plugins that cannot be secured are disabled in sandboxed browsing contexts because they might not honor the restrictions imposed by the sandbox (e.g. they might allow scripting even when scripting in the sandbox is disabled). User agents should convey the danger of overriding the sandbox to the user if an option to do so is provided.

The embed element potentially delays the load event.

name、align、hspace、およびvspace以外の名前空間なしの属性は、その名前がXML互換性があり、ASCII大文字を一切含まない限り、embed要素で指定されてもよい。これらの属性は、プラグインにパラメーターとして渡される。

大文字の制限がそのような文書に影響しないので、HTML文書内のすべての属性は自動的に小文字を取得する。

4つの例外は、プラグインに送信するパラメーターを超えた副作用を持つ従来の属性を除外するのに適当である。

The user agent should pass the names and values of all the attributes of the embed element that have no namespace to the plugin used, when one is instantiated.

The HTMLEmbedElement object representing the element must expose the scriptable interface of the plugin instantiated for the embed element, if any.

embed要素は、次元属性をサポートする。

IDL属性src、およびtypeのそれぞれは、同じ名前の各コンテンツ属性を反映しなければならない。

<embed src="catgame.swf">

<embed src="catgame.swf" quality="high">

<object data="catgame.swf">
 <param name="quality" value="high">
</object>

4.8.7 object要素

カテゴリー：

フローコンテンツ。

フレージングコンテンツ。

エンベディッドコンテンツ。

要素がusemap属性をもつ場合：インタラクティブコンテンツ。

リストおよび提出可能 フォーム関連要素。

パルパブルコンテンツ。

この要素を使用できるコンテキスト：

エンベディッドコンテンツが期待される場所。

コンテンツモデル：

0個以上のparam要素、それから透過的。

text/htmlにおけるタグ省略：

どちらのタグも省略不可。

コンテンツ属性：

グローバル属性

data — リソースのアドレス

type — 埋め込みリソースタイプ

name — ネストされたブラウジングコンテキスト名

usemap — 使用するイメージマップの名前

form — form要素とこの要素を関連付ける

width — 横の次元

height — 縦の次元

アクセシビリティの考慮：

著者向け。

実装者向け。

DOMインターフェイス：

[Exposed=Window]
interface HTMLObjectElement : HTMLElement {
  [HTMLConstructor] constructor();

  [CEReactions] attribute USVString data;
  [CEReactions] attribute DOMString type;
  [CEReactions] attribute DOMString name;
  [CEReactions] attribute DOMString useMap;
  readonly attribute HTMLFormElement? form;
  [CEReactions] attribute DOMString width;
  [CEReactions] attribute DOMString height;
  readonly attribute Document? contentDocument;
  readonly attribute WindowProxy? contentWindow;
  Document? getSVGDocument();

  readonly attribute boolean willValidate;
  readonly attribute ValidityState validity;
  readonly attribute DOMString validationMessage;
  boolean checkValidity();
  boolean reportValidity();
  void setCustomValidity(DOMString error);

  // also has obsolete members
};

Depending on the type of content instantiated by the object element, the node also supports other interfaces.

The object element can represent an external resource, which, depending on the type of the resource, will either be treated as an image, as a child browsing context, or as an external resource to be processed by a plugin.

data属性は存在する場合、リソースのURLを指定する。存在する場合、属性は、潜在的にスペースで囲まれた妥当な空でないURLでなければならない。

著者は、信頼できないリソースの参照を避けるべきである。そのようなリソースは、著者がFlashの"allowScriptAccess"パラメーターなどの機能を使用した場合でも、プラグインのインスタンス化やスクリプトの実行に使用できる。

type属性が存在する場合、リソースのタイプを指定する。存在する場合、属性は妥当なMIMEタイプ文字列でなければならない。

data属性またはtype属性のいずれか一方が少なくとも存在しなければならない。

object要素でitempropが指定される場合、data属性も指定されなければならない。

name属性が存在する場合、妥当なブラウジングコンテキスト名でなければならない。The given value is used to name the element's nested browsing context, if applicable, and if present when the element's nested browsing context is created.

Whenever one of the following conditions occur:

• the element is created,
• the element is popped off the stack of open elements of an HTML parser or XML parser,
• the element is not on the stack of open elements of an HTML parser or XML parser, and it is either inserted into a document or removed from a document,
• the element's node document changes whether it is fully active,
• one of the element's ancestor object elements changes to or from showing its fallback content,
• the element's classid attribute is set, changed, or removed,
• the element's classid attribute is not present, and its data attribute is set, changed, or removed,
• neither the element's classid attribute nor its data attribute are present, and its type attribute is set, changed, or removed,
• the element changes from being rendered to not being rendered, or vice versa,

...the user agent must queue an element task on the DOM manipulation task source given the object element to run the following steps to (re)determine what the object element represents. This task being queued or actively running must delay the load event of the element's node document.

1. If the user has indicated a preference that this object element's fallback content be shown instead of the element's usual behavior, then jump to the step below labeled fallback.

   For example, a user could ask for the element's fallback content to be shown because that content uses a format that the user finds more accessible.

2. If the element has an ancestor media element, or has an ancestor object element that is not showing its fallback content, or if the element is not in a document whose browsing context is non-null, or if the element's node document is not fully active, or if the element is still in the stack of open elements of an HTML parser or XML parser, or if the element is not being rendered, or if the Should element be blocked a priori by Content Security Policy? algorithm returns "Blocked" when executed on the element, then jump to the step below labeled fallback. [CSP]

3. If the classid attribute is present, and has a value that isn't the empty string, then: if the user agent can find a plugin suitable according to the value of the classid attribute, and either plugins aren't being sandboxed or that plugin can be secured, then that plugin should be used, and the value of the data attribute, if any, should be passed to the plugin. If no suitable plugin can be found, or if the plugin reports an error, jump to the step below labeled fallback.

4. If the data attribute is present and its value is not the empty string, then:

   1. If the type attribute is present and its value is not a type that the user agent supports, and is not a type that the user agent can find a plugin for, then the user agent may jump to the step below labeled fallback without fetching the content to examine its real type.

   2. Parse the URL specified by the data attribute, relative to the element's node document.

   3. If that failed, fire an event named error at the element, then jump to the step below labeled fallback.

   4. Let request be a new request whose url is the resulting URL record, client is the element's node document's relevant settings object, destination is "object", credentials mode is "include", mode is "navigate", and whose use-URL-credentials flag is set.

   5. Fetch request.

      Fetching the resource must delay the load event of the element's node document until the task that is queued by the networking task source once the resource has been fetched (defined next) has been run.

      For the purposes of the application cache networking model, this fetch operation is not for a child browsing context (though it might end up being used for one after all, as defined below).

   6. If the resource is not yet available (e.g. because the resource was not available in the cache, so that loading the resource required making a request over the network), then jump to the step below labeled fallback. The task that is queued by the networking task source once the resource is available must restart this algorithm from this step. Resources can load incrementally; user agents may opt to consider a resource "available" whenever enough data has been obtained to begin processing the resource.

   7. If the load failed (e.g. there was an HTTP 404 error, there was a DNS error), fire an event named error at the element, then jump to the step below labeled fallback.

   8. Determine the resource type, as follows:

      1. Let the resource type be unknown.

      2. If the user agent is configured to strictly obey Content-Type headers for this resource, and the resource has associated Content-Type metadata, then let the resource type be the type specified in the resource's Content-Type metadata, and jump to the step below labeled handler.

         This can introduce a vulnerability, wherein a site is trying to embed a resource that uses a particular plugin, but the remote site overrides that and instead furnishes the user agent with a resource that triggers a different plugin with different security characteristics.

      3. If there is a type attribute present on the object element, and that attribute's value is not a type that the user agent supports, but it is a type that a plugin supports, then let the resource type be the type specified in that type attribute, and jump to the step below labeled handler.

      4. Run the appropriate set of steps from the following list:

         If the resource has associated Content-Type metadata

         1. Let binary be false.

         2. If the type specified in the resource's Content-Type metadata is "text/plain", and the result of applying the rules for distinguishing if a resource is text or binary to the resource is that the resource is not text/plain, then set binary to true.

         3. If the type specified in the resource's Content-Type metadata is "application/octet-stream", then set binary to true.

         4. If binary is false, then let the resource type be the type specified in the resource's Content-Type metadata, and jump to the step below labeled handler.

         5. If there is a type attribute present on the object element, and its value is not application/octet-stream, then run the following steps:

            1. If the attribute's value is a type that a plugin supports, or the attribute's value is a type that starts with "image/" that is not also an XML MIME type, then let the resource type be the type specified in that type attribute.

            2. Jump to the step below labeled handler.

         Otherwise, if the resource does not have associated Content-Type metadata

         1. If there is a type attribute present on the object element, then let the tentative type be the type specified in that type attribute.

            Otherwise, let tentative type be the computed type of the resource.

         2. If tentative type is not application/octet-stream, then let resource type be tentative type and jump to the step below labeled handler.

      5. If applying the URL parser algorithm to the URL of the specified resource (after any redirects) results in a URL record whose path component matches a pattern that a plugin supports, then let resource type be the type that that plugin can handle.

         For example, a plugin might say that it can handle resources with path components that end with the four character string ".swf".

      It is possible for this step to finish, or for one of the substeps above to jump straight to the next step, with resource type still being unknown. In both cases, the next step will trigger fallback.

   9. Handler: Handle the content as given by the first of the following cases that matches:

      If the resource type is not a type that the user agent supports, but it is a type that a plugin supports

      If the object element's nested browsing context is non-null, then it must be discarded and then set to null.

      If plugins are being sandboxed and the plugin that supports resource type cannot be secured, jump to the step below labeled fallback.

      Otherwise, the user agent should use the plugin that supports resource type and pass the content of the resource to that plugin. If the plugin reports an error, then jump to the step below labeled fallback.

      If the resource type is an XML MIME type, or if the resource type does not start with "image/"

      If the object element's nested browsing context is null, then create a new nested browsing context for the element.

      If the URL of the given resource is not about:blank, the element's nested browsing context must then be navigated to that resource, with replacement enabled, and with the object element's node document's browsing context as the source browsing context. (The data attribute of the object element doesn't get updated if the browsing context gets further navigated to other locations.)

      If the URL of the given resource is about:blank, then, instead, the user agent must queue an element task on the DOM manipulation task source given the object element to fire an event named load at the object element. No load event is fired at the about:blank document itself.

      The object element represents its nested browsing context.

      In certain situations, e.g., if the resource was fetched from an application cache but it is an HTML file with a manifest attribute that points to a different application cache manifest, the navigation of the browsing context will be restarted so as to load the resource afresh from the network or a different application cache. Even if the resource is then found to have a different type, it is still used as part of a browsing context: only the navigate algorithm is restarted, not this object algorithm.

      If the resource type starts with "image/", and support for images has not been disabled

      If the object element's nested browsing context is non-null, then it must be discarded and then set to null.

      Apply the image sniffing rules to determine the type of the image.

      The object element represents the specified image.

      If the image cannot be rendered, e.g. because it is malformed or in an unsupported format, jump to the step below labeled fallback.

      そうでなければ

      The given resource type is not supported. Jump to the step below labeled fallback.

      If the previous step ended with the resource type being unknown, this is the case that is triggered.

   10. The element's contents are not part of what the object element represents.

   11. Return. Once the resource is completely loaded, queue an element task on the DOM manipulation task source given the object element to fire an event named load at the element.

5. If the data attribute is absent but the type attribute is present, and the user agent can find a plugin suitable according to the value of the type attribute, and either plugins aren't being sandboxed or the plugin can be secured, then that plugin should be used. If these conditions cannot be met, or if the plugin reports an error, jump to the step below labeled fallback. Otherwise return; once the plugin is completely loaded, queue an element task on the DOM manipulation task source given the object element to fire an event named load at the element.

6. Fallback: The object element represents the element's children, ignoring any leading param element children. This is the element's fallback content. If the element has an instantiated plugin, then unload it. If the element's nested browsing context is non-null, then it must be discarded and then set to null.

When the algorithm above instantiates a plugin, the user agent should pass to the plugin used the names and values of all the attributes on the element, in the order they were added to the element, with the attributes added by the parser being ordered in source order, followed by a parameter named "PARAM" whose value is null, followed by all the names and values of parameters given by param elements that are children of the object element, in tree order. If the plugin supports a scriptable interface, the HTMLObjectElement object representing the element should expose that interface. The object element represents the plugin. The plugin is not a nested browsing context.

Plugins are considered sandboxed for the purpose of an object element if the sandboxed plugins browsing context flag is set on the object element's node document's active sandboxing flag set.

Due to the algorithm above, the contents of object elements act as fallback content, used only when referenced resources can't be shown (e.g. because it returned a 404 error). This allows multiple object elements to be nested inside each other, targeting multiple user agents with different capabilities, with the user agent picking the first one it supports.

The object element potentially delays the load event.

object要素が画像を表すと同時に存在する場合、usemap属性は、イメージマップに関連付けられるオブジェクトを持つことを示すことができる。object要素が画像を表さない場合、この属性は無視されなければならない。

form属性は、明示的にそのフォームの所有者とobject要素を関連付けるために使用される。

Constraint validation: object elements are always barred from constraint validation.

object要素は次元属性をサポートする。

IDL属性data、typeおよびnameのそれぞれは、同じ名前の各コンテンツ属性を反映しなければならない。The useMap IDL attribute must reflect the usemap content attribute.

The contentDocument IDL attribute, on getting, must return the object element's content document.

The contentWindow IDL attribute must return the WindowProxy object of the object element's nested browsing context, if its nested browsing context is non-null; otherwise, it must return null.

The willValidate, validity, and validationMessage attributes, and the checkValidity(), reportValidity(), and setCustomValidity() methods, are part of the constraint validation API. The form IDL attribute is part of the element's forms API.

<figure>
 <object data="clock.html"></object>
 <figcaption>My HTML Clock</figcaption>
</figure>

<p>Look at my video:
 <object type="application/x-shockwave-flash">
  <param name=movie value="https://video.example.com/library/watch.swf">
  <param name=allowfullscreen value=true>
  <param name=flashvars value="https://video.example.com/vids/315981">
  <video controls src="https://video.example.com/vids/315981">
   <a href="https://video.example.com/vids/315981">View video</a>.
  </video>
 </object>
</p>

4.8.8 param要素

カテゴリー：

なし。

この要素を使用できるコンテキスト：

任意のフローコンテンツの前の、object要素の子として。

コンテンツモデル：

Nothing。

text/htmlにおけるタグ省略：

終了タグなし。

コンテンツ属性：

グローバル属性

name — パラメーター名

value — パラメーター値

アクセシビリティの考慮：

著者向け。

実装者向け。

DOMインターフェイス：

[Exposed=Window]
interface HTMLParamElement : HTMLElement {
  [HTMLConstructor] constructor();

  [CEReactions] attribute DOMString name;
  [CEReactions] attribute DOMString value;

  // also has obsolete members
};

param要素は、object要素によって呼び出されるプラグインのパラメーターを定義する。この要素は、自分自身で何かを表すものではない。

name属性は、パラメーターの名前を与える。

value属性は、パラメーターの値を与える。

両方の属性が存在しなければならない。これらは、任意の値を持ってもよい。

If both attributes are present, and if the parent element of the param is an object element, then the element defines a parameter with the given name-value pair.

If either the name or value of a parameter defined by a param element that is the child of an object element that represents an instantiated plugin changes, and if that plugin is communicating with the user agent using an API that features the ability to update the plugin when the name or value of a parameter so changes, then the user agent must appropriately exercise that ability to notify the plugin of the change.

IDL属性nameおよびvalueは、同じ名前の各コンテンツ属性を両方反映しなければならない。

<!DOCTYPE HTML>
<html lang="en">
  <head>
   <title>O3D Utah Teapot</title>
  </head>
  <body>
   <p>
    <object type="application/vnd.o3d.auto">
     <param name="o3d_features" value="FloatingPointTextures">
     <img src="o3d-teapot.png"
          title="3D Utah Teapot illustration rendered using O3D."
          alt="When O3D renders the Utah Teapot, it appears as a squat
          teapot with a shiny metallic finish on which the
          surroundings are reflected, with a faint shadow caused by
          the lighting.">
     <p>To see the teapot actually rendered by O3D on your
     computer, please download and install the <a
     href="http://code.google.com/apis/o3d/docs/gettingstarted.html#install">O3D plugin</a>.</p>
    </object>
    <script src="o3d-teapot.js"></script>
   </p>
  </body>
</html>