[5] [DFN[[RUBYB[[[変異観測器]]]@en[mutation observer]]]] ([DFN[[[変異オブザーバー]]]]) は、 [[DOM]] の変化の通知を[[スクリプト]]が受け取るための仕組みです。 予め所定の方法で観測器となる[[コールバック関数]]を指定することで、 [[DOM木]]における[[子供]]や[[属性]]の変化を観測し、そのタイミングで処理を行うことができます。 * 処理 [33] [[変異観測器]]は、[[変異]]が発生した[[タスク]]の処理後、[[マイクロタスク]]として呼び出されます。 * ごみ収集 [19] [[ごみ収集]]も参照。 [21] [CODE[observe]] した[[変異観測器]]は、[[節点]]から[[強い参照]]を持たれます。 従って、 [[JavaScript]] のコードから[[変異観測器]]への参照が無くなっても、 引き続き動作を続けます。不要になった時は、 (参照を無くす前に) [CODE[disconnect]] する必要があります。 * 歴史 ** 変異イベントから変異観測器へ [4] [[変異観測器]]は、[[変異イベント]]の代替として考案され、 [[DOM4]] 仕様に取り込まれました。 [REFS[ - [31] [CITE@en[DOM Mutation Events Replacement: The Story So Far / Existing Points of Consensus]] ([[Rafael Weinstein]] 著, [TIME[2011-08-11 09:41:29 +09:00]] 版) - [32] [CITE@en[DOM Mutation Events Replacement: When to deliver mutations]] ([[Rafael Weinstein]] 著, [TIME[2011-08-11 09:44:32 +09:00]] 版) - [30] [CITE@en[Mutation Observers: a replacement for DOM Mutation Events]] ([[Adam Klein]] 著, [TIME[2011-09-24 06:16:40 +09:00]] 版) - [1] [CITE[IRC logs: freenode / #whatwg / 20120228]] ( ([TIME[2012-03-08 00:01:17 +09:00]] 版)) ]REFS] [34] [[変異観測器]]の呼び出しは[[イベントループ]]と密接に関わっているため、 [[HTML Standard]] で規定されました。 ** 構文解析器と変異観測器 [35] [[変異イベント]]は[[構文解析]]によって生じる [[DOM木]]の変化については発生しないことになっていましたが、 [[変異観測器]]はそれも観測できることと規定されました。 [REFS[ - [20] [CITE@en[Web Applications 1.0 r7484 The parser should have mutation observers.]] ([TIME[2012-10-24 07:24:00 +09:00]] 版) ]REFS] [36] [CITE[Integrate with the new microtask world order. https://www.w3.org/Bugs/Pu... · d8b0057 · whatwg/dom]] ( ([TIME[2014-04-12 08:37:53 +09:00]] 版)) [37] [CITE@en[Exceptions thrown from mutation observer callbacks should be reported pe... · 2e567d3 · whatwg/dom]] ( ([TIME[2014-11-30 15:00:21 +09:00]] 版)) [2] [CITE@en[Replacing a child within parent had the wrong previousSibling in its … · whatwg/dom@d9fbd12]] ([TIME[2015-07-24 22:54:57 +09:00]] 版) [3] [CITE@en[Always queue mutation records after said mutations. Fixes #60. · whatwg/dom@bc31c18]] ([TIME[2015-07-30 14:20:02 +09:00]] 版) [6] [CITE@en[Close #122: fix mutation record for a removing a node · whatwg/dom@9202ada]] ([TIME[2015-11-28 12:16:46 +09:00]] 版) [7] [CITE@en[Clarify initial state of "mutation observer compound microtask queued… · whatwg/dom@f2427d8]] ([TIME[2016-01-02 11:22:08 +09:00]] 版) [8] [CITE@en[Reword queue a mutation record to avoid "continue" · whatwg/dom@d3653ac]] ([TIME[2016-03-15 12:11:44 +09:00]] 版) [9] [CITE@en[23250 – No way with mutation observers to watch mutations to an element's parent]] ([TIME[2016-04-16 13:05:52 +09:00]] 版) [10] [CITE@en[Do not let mutation observer callbacks influence the used signal slot…]] ( ([[annevk]]著, [TIME[2016-06-09 16:27:03 +09:00]])) [11] [CITE@en[Web Applications 1.0 r7009 Add support for MutationObservers. (Also, add a minor internal note in the canvas section unrelated to this.) (Also, automated update of the CLDR which resulted in removing separate support for el-POLYTON.)]] ( ([TIME[2012-03-01 06:24:00 +09:00]] 版)) [12] [CITE[IRC logs: freenode / #whatwg / 20120409]] ( ([TIME[2012-04-15 13:32:46 +09:00]] 版)) [13] [CITE[IRC logs: freenode / #whatwg / 20120830]] ( ([TIME[2012-09-05 21:57:54 +09:00]] 版)) [14] [CITE[IRC logs: freenode / #whatwg / 20120922]] ( ([TIME[2012-09-24 20:09:27 +09:00]] 版)) [15] [CITE@en[Web Applications 1.0 r7484 The parser should have mutation observers.]] ( ([TIME[2012-10-24 07:24:00 +09:00]] 版)) [16] [CITE[Bug 16142 – Spec delivery semantics for MutationObservers]] ( ([TIME[2012-03-08 00:07:58 +09:00]] 版)) [17] [CITE@en[Require one of childList, attributes, and characterData to be true after... · 4bf29a4 · whatwg/dom]] ( ([TIME[2014-10-23 02:24:57 +09:00]] 版)) [18] [[構文解析器]]の動作と [CODE(DOMi)@en[[[MutationObserver]]]] の呼び出しタイミングの関係は[[ブラウザー]]ごとに全然違っているようです。 [TIME[2016-02-22T15:39:28.500Z]] [22] [CITE@en[Mark observe()'s dictionary argument as optional]] ([[annevk]]著, [TIME[2016-08-29 15:45:52 +09:00]]) [23] [CITE@en[Clarify insert-node's record's previousSibling]] ([[bwrrp]]著, [TIME[2017-05-31 19:00:09 +09:00]]) [24] [CITE@en[Clarify insert-node's record's previousSibling by bwrrp · Pull Request #464 · whatwg/dom]] ([TIME[2017-06-29 16:02:06 +09:00]]) [25] [CITE@en[Add '''['''Exposed=Window''']''' to MutationObserver]] ([[annevk]]著, [TIME[2017-09-06 17:37:07 +09:00]]) [26] [CITE@en[Add '''['''Exposed=Window''']''' to MutationObserver by annevk · Pull Request #507 · whatwg/dom]] ([TIME[2017-09-07 12:06:07 +09:00]]) [27] [CITE@en[Hide `nonce` content attribute values. (#2369) by mikewest · Pull Request #2373 · whatwg/html]] ([TIME[2018-02-17 23:35:36 +09:00]]) [28] [CITE@en[Editorial: use Infra to define mutation observers]] ([[annevk]]著, [TIME[2018-03-29 20:12:35 +09:00]]) [29] [CITE@en[Small correct for Mutation observers · Issue #132 · whatwg/dom]] ([TIME[2018-03-30 15:39:22 +09:00]]) [38] [CITE@en[Use Infra to define mutation observers by annevk · Pull Request #609 · whatwg/dom]] ([TIME[2018-03-30 15:39:59 +09:00]]) [39] [CITE@en[Use DOM's "replace all" primitive in document.open()]] ([[annevk]]著, [TIME[2018-05-01 01:44:29 +09:00]]) [40] [CITE@en[Use DOM's "replace all" primitive in document.open() by annevk · Pull Request #3598 · whatwg/html]] ([TIME[2018-05-03 10:36:31 +09:00]]) [41] [[Edge]] は [CODE[observe]] [[メソッド]]のオプションに何も指定されていないとき [CODE[SyntaxError]] を[[投げ]]ます。 [TIME[2018-12-13T03:45:07.800Z]] [42] [[Edge]] は [CODE[observe]] [[メソッド]]のオプションに [CODE[attributeFilter]] が指定されて [CODE[attributes]] が指定されていないとき、 [CODE[SyntaxError]] を[[投げ]]ます。 [TIME[2018-12-13T03:45:43.900Z]] [43] [CITE@en[Align with IDL dictionary changes]] ([[annevk]]著, [TIME[2019-08-09 00:54:02 +09:00]]) [44] [CITE@en[Align with IDL constructor changes]] ([[autokagami]]著, [TIME[2019-09-24 22:42:56 +09:00]]) [45] [CITE@en[Use Web IDL constructor operations by foolip · Pull Request #782 · whatwg/dom]] ([TIME[2020-05-14 14:05:50 +09:00]]) [46] [CITE@en[Remove compound microtasks]] ([[annevk]], [TIME[2019-03-30 00:11:20 +09:00]], [TIME[2021-03-25T11:58:33.000Z]]) [47] [CITE@en[Dispatching slotchange within a compound microtask · Issue #734 · whatwg/dom]] ([TIME[2021-03-25T12:03:27.000Z]]) [48] [CITE@en[Remove compound microtasks by annevk · Pull Request #741 · whatwg/dom]] ([TIME[2021-03-25T12:04:41.000Z]]) [49] [CITE@en[Editorial: embrace that attributes are objects]] ([[annevk]], [TIME[2019-12-12 02:40:19 +09:00]], [TIME[2022-01-27T11:50:04.000Z]])