2nd/10_Wiki/Topics/Domain_Programming/Topic_W3CSS/W3CSS_Slideshow.md

id, title, category, status, verification_status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, created_at, updated_at, review_reason, merge_history, tags, raw_sources, applied_in, github_commit

id	title	category	status	verification_status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	created_at	updated_at	review_reason	merge_history	tags	raw_sources	applied_in	github_commit
w3css-slideshow	W3CSS Slideshow	Programming_Language	draft	conceptual		carousel mySlides w3-display-container W3.CSS 슬라이드쇼		B	0.87	2026-07-04	2026-07-04			w3css css-framework w3schools slideshow carousel	https://www.w3schools.com/w3css/w3css_slideshow.asp

W3CSS Slideshow

🎯 한 줄 통찰 (One-line insight)

The manual and automatic slideshow share IDENTICAL slide-hiding logic — the only real difference is WHAT triggers the index change: plusDivs() called by a button click (manual) versus setTimeout(carousel, 2000) recursively calling itself (automatic) — meaning a "carousel" is simply a slideshow whose advance function schedules its own next call instead of waiting for user input. [S1]

🧠 핵심 개념 (Core concepts)

• Shared-class slides — every slide element uses the same class (mySlides), just like the Tabulators pattern; JS hides all, then shows one by index. [S1]
• slideIndex wraparound — manual version resets to 1 if the index exceeds slide count, or to the last slide if it goes below 1, allowing infinite forward/backward cycling. [S1]
• Automatic carousel — carousel() calls itself via setTimeout(carousel, 2000) at the end of its own execution, creating a self-perpetuating timer loop (distinct from setInterval, which the Progress Bar chapter used instead). [S1]
• HTML slides, not just images — slides can be any HTML content (styled divs with text), not restricted to <img>. [S1]
• Caption + indicator overlays — reuse w3-display-container/w3-display-bottomleft (from the Display chapter) for captions, and clickable w3-badge or numbered buttons as slide indicators via a currentDiv(n) function. [S1]
• Multiple independent slideshows per page — achieved simply by giving each slideshow group a UNIQUE class name (mySlides1, mySlides2) so their JS loops don't interfere. [S1]

📖 세부 내용 (Details)

• Manual slideshow core logic: function showDivs(n) { var i; var x = document.getElementsByClassName("mySlides"); if (n > x.length) {slideIndex = 1} if (n < 1) {slideIndex = x.length}; for (i = 0; i < x.length; i++) { x[i].style.display = "none"; } x[slideIndex-1].style.display = "block"; }. [S1]
• Automatic carousel (self-scheduling timer): function carousel() { ...hide all...; slideIndex++; if (slideIndex > x.length) {slideIndex = 1} x[slideIndex-1].style.display = "block"; setTimeout(carousel, 2000); }. [S1]
• Caption overlay: <div class="w3-display-container mySlides"><img src="img_snowtops.jpg" style="width:100%"><div class="w3-display-bottomleft w3-container w3-padding-16 w3-black">French Alps</div></div>. [S1]
• Independent multi-slideshow class separation: mySlides1 for one group, mySlides2 for another, entirely separate getElementsByClassName calls. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

• setTimeout 재귀 호출 vs setInterval: 자동 슬라이드쇼는 setInterval이 아니라 carousel() 함수가 자기 자신을 setTimeout으로 다시 예약하는 재귀적 방식이라는 점이 프로그레스 바 챕터의 setInterval 방식과 대비됨. [S1]

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — 모달 챕터에서 언급된 "라이트박스(Lightbox)" 패턴이 슬라이드쇼를 모달 안에 내장하는 실전 조합 사례로 예고됨. [S1]

💻 코드 패턴 (Code patterns)

Self-scheduling automatic carousel using setTimeout recursion (JavaScript):

var slideIndex = 0;
carousel();
function carousel() {
  var i;
  var x = document.getElementsByClassName("mySlides");
  for (i = 0; i < x.length; i++) {
    x[i].style.display = "none";
  }
  slideIndex++;
  if (slideIndex > x.length) {slideIndex = 1}
  x[slideIndex-1].style.display = "block";
  setTimeout(carousel, 2000); // Change image every 2 seconds
}

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.87
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: W3.CSS Tutorial
• 관련 개념: W3CSS Progress Bar, W3CSS Tabulators, W3CSS Modal
• 참조 맥락: 타이머 기반 동적 UI의 두 번째 사례 — 모달(Modal) 챕터에서 라이트박스 조합으로 재등장.

📚 출처 (Sources)

• [S1] W3Schools — W3.CSS Slideshow — https://www.w3schools.com/w3css/w3css_slideshow.asp

📝 변경 이력 (Change history)

• 2026-07-04: Initial draft synthesized from the W3Schools "W3.CSS Slideshow" page (Astra wiki-curation, P-Reinforce v3.1 format).