PDF BBCode Tag to Automatically Display All PDFs

[Chip (OP)]

Work in Progress For Simple Machines

Instructions yet to be given to Claude.ai:
---------------------------------------------
Build (read on) what we currently support now and then incrementally, perhaps at the end of every session, build a downloadable file that lists EACH and EVERY markdown we support and supply an example of its raw text -- and please don't forget any CSS if warranted.

In the end we will have a thorough and concise manual/handbook to both support and document ourmod's powerful capabilities -- this is to be world-standard breadth of rendering.

Implementing Mozilla's PDF Javascript Viewer by BBCode Tags
Written by Chipper (Andrew Egerszegi) with Claude.ai
Compatibility: SMF 2.0.x & SMF 2.1.x
Description and Notes
Rendered with a bundled, self-hosted copy of Mozilla's PDF.js viewer in an <iframe>.

* Three ways to use the tag:

   
   * [pdf]https://example.com/file.pdf[/pdf]
    - displays a locally stored pdf file in web root   

    * [pdf=attach-nn]x[/pdf]
    - displays the attachment (starts from 0)
 
    * [pdf=autodisplay]x[/pdf]
    - displays every PDF attached to this post automatically
   
   * [pdf=noautodisplay]x[/pdf]
    - stop the automatic display of all attached PDF files
   

Modifying the PDF Viewer defaults:

To set the scroll mode (`ScrollMode.PAGE = 3` — that's "one page at a time, scroll/navigate between them" (what you want, instead of continuous vertical which is `VERTICAL = 0`).

nano +4435 /var/www/html/Themes/default/pdfjs/web/viewer.mjs

Change `-1` → `3` (shown below)

Code: [Select]

  scrollModeOnLoad: {
    value: 3,
    kind: OptionKind.VIEWER + OptionKind.PREFERENCE
  },

Leave `spreadModeOnLoad` at `-1` (that controls side-by-side two-page spreads, unrelated to what you want). Reload a PDF after saving and it should open one page at a time with prev/next navigation instead of the continuous scroll.

Testing:

Display by URL to its webroot filename


Display by attachment id


Display every attachment automatically
[pdf=autodisplay]x[/pdf]

[smfadmin]

Checkpoint: MD BBCode Mod — GFM Conformance Pass

Purpose: bring Andrew's SMF Markdown BBCode mod (MDParser.php/MDBBC.php) up to a level of GFM spec conformance good enough to satisfy SMF's lead dev, who recommended testing against the full GFM spec (https://github.github.com/gfm/) after reviewing the mod for possible official SMF inclusion.

Files / components

File	Status	Use it?
MDParser.php (this session's patched version, attached)	Patched: emphasis rewrite, loose/tight lists, indented-code blank-line merging, link destination fixes, code span fix, bare-URL/www/email autolinking	Yes — this is the current working version, supersedes the originally-uploaded copy
MDBBC.php (originally uploaded)	Untouched this session — no changes were needed	Yes, unchanged
MD_SYNTAX_MANUAL.md (attached)	Full table of every currently-supported syntax element + raw/rendered examples, generated from the actual current parser	Yes — hand this to anyone (including SM) who wants to see current scope
extract_spec.py (attached)	One-time script: pulls cmark-gfm's test/spec.txt and converts it to spec.json (672 examples, tagged by section/extension)	Only needed if spec.json (attached separately) is ever lost — otherwise skip straight to run_tests.php
spec.json (attached)	Already-extracted output of extract_spec.py — the 672-example test suite itself	Yes — drop it next to MDParser.php and run_tests.php, no re-fetch needed
run_tests.php (attached)	Runs MDParser.php against every example in spec.json, writes results.json	Re-run after every parser change
analyze.py (attached)	Reads results.json, applies a "cosmetic-diff-tolerant" normalizer (strips our own CSS classes, rel= attribute, self-closing-tag style, tag-per-line formatting) to separate real bugs from harmless serialization differences; writes real_failures.json and prints per-section pass rates	Re-run after every run_tests.php run

Verified facts — don't re-check

• The GFM spec's machine-readable test suite lives at test/spec.txt in github/cmark-gfm on GitHub (raw: raw.githubusercontent.com/github/cmark-gfm/master/test/spec.txt), in a literate format (fenced blocks marked `...`` example [extension-name] , input, a lone . line, expected HTML, closing fence). extract_spec.py parses this correctly — 672 examples extracted, matching the known canonical GFM spec size.
• PHP is not preinstalled in this environment; apt-get install -y php-cli works (no sudo needed, container runs as root) and pulls PHP 8.3.
• Raw pass rate (exact string match) is a bad metric here — many of the mod's own intentional additions (CSS classes md-code-block/md-table, the rel="noopener noreferrer nofollow" security hardening on links, HTML5-style non-self-closing tags) cosmetically differ from the reference renderer's output without being bugs. Always read the normalized pass rate from analyze.py, and treat real_failures.json (not raw results.json) as the list of genuine bugs.
• Confirmed baseline at session start: 138/672 raw, 282/672 (42%) normalized.
• Confirmed after this session's fixes: 200/672 raw, 396/672 (59%) normalized.
• Confirmed ceiling: literal 672/672 is not a sensible goal. Reference-style links/link-reference-definitions and full raw-HTML-block parsing are deliberately out of scope (~100+ examples) — the latter because supporting it would conflict with the mod's "escape everything, selectively re-decode" security model, which the prior external security review specifically hardened. Realistic achievable ceiling is roughly 550–600/672 (~85-90%).
• Confirmed via direct testing against the npm commonmark reference package: one spec example (__foo, __bar__, baz__) has an expected output in cmark-gfm's own spec.txt that disagrees with what the reference implementation's actual delimiter-stack algorithm produces (nested vs. flat <strong>). Traced this to the algorithm level, not a wasted rabbit hole — treat as a known, accepted gray area, do not re-derive.
• Andrew's stated priority order (confirmed, his words): emphasis + list nesting first (highest-traffic, most complaint-prone), then links + blockquote laziness, then headings/tables (already solid), then fenced/indented code + thematic breaks/autolinks/escaping (lowest priority).
• Andrew has separately built a syntax reference manual for the &#91;md&#93; tag on his own and confirmed it renders well — this may or may not be the same document as MD_SYNTAX_MANUAL.md above; worth asking rather than assuming they're the same artifact.
• Forum BBC policy: all standard BBCode tags are disabled except [nobbc] (kept enabled/exempt as the literal-text escape hatch) and [md] itself. This is stated in MD_SYNTAX_MANUAL.md's header warning and in MDBBC.php's top doc-comment — check both stay in sync if the policy ever changes.

Open items (decisions, not blockers)

• Base angle-bracket autolink (<scheme://...>) only recognizes http/https/ftp/ftps/mailto. CommonMark's actual rule allows any scheme matching [a-zA-Z][a-zA-Z0-9+.-]{1,31}:. Decision needed: is broadening this worth it for a forum (real schemes people might paste: irc://, magnet:, steam://), or is the current allowlist a deliberate security stance worth keeping as-is?
• Link destinations don't yet balance parens ((foo(bar)) inside a bare URL) or do full percent-encoding of unsafe characters — only literal-space encoding is implemented. Decision needed: how much of this edge case is worth chasing given forum posts rarely paste raw unencoded URLs with parens.
• Blockquote laziness (continuation lines without a leading >) is now fixed for the common case (paragraph continuation only, not headings/lists/fences/thematic breaks/indented code, and not after a blank line). Remaining edge case: laziness tracking inside an already-open non-paragraph block within a quote (e.g. an unclosed fence) isn't precise - low priority.
• List "same list vs new list" rules fixed this session: a changed bullet character (-/*/+) or ordered delimiter style (. vs )) now correctly starts a new list; an ordered list can only interrupt a paragraph if it starts at 1.
• Link destinations now do real percent-encoding (HTML entity decode, then percent-encode any byte outside the URL-safe set while preserving existing valid %XX sequences) and correctly balance parentheses via a recursive regex ([link](foo(and(bar))) works). Caution for future edits: adding a named recursive group inside an existing capturing group shifts the numeric index of every group after it — this caused a real regression this session (title text silently became a duplicate of the URL) until the shifted indices were corrected. Double-check group numbering with a quick preg_match test whenever the link/image regex structure changes again.
• Link destinations still don't do full percent-encoding (backslash → %5C, HTML entities like ä → %C3%A4, non-ASCII chars, quotes in a titleless destination) — only literal-space encoding is implemented. This is the largest remaining Links gap (roughly a dozen of the remaining ~53 failures).
• Angle-bracket link destinations spanning a literal line break ([link](<foo\nbar>), which per spec should NOT be a valid link) aren't rejected, because paragraph-line-joining happens at the block level before this inline check ever sees the newline — a real but low-priority structural limitation.
• Whether to reconcile/merge with Andrew's own separately-built syntax manual, or keep MD_SYNTAX_MANUAL.md as this session's independent version.

Next actual action

Run analyze.py's per-section breakdown on the current real_failures.json. Links is now largely down to reference-style-link failures (out of scope) plus a handful of exotic raw-HTML-mixed-with-brackets edge cases — List items (32/48) and Lists (13/26) are the next-best-value targets. Starting a fresh session should: install php-cli (apt-get install -y php-cli, no sudo needed), drop all six attached files in one directory, then run php run_tests.php && python3 analyze.py, and pick up from there.

[smfadmin]

Topic bumped