Pinboard.in firefox (think any browser) bookmarklet to save arxiv title, abstract (as description), then authors, year and subjects (as tags)

README.md

🧠 Lessons Learned: Building a Reliable Pinboard Bookmarklet

Creating a dependable Pinboard bookmarklet — especially for extracting structured data from sites like arXiv.org — sounds simple, but there are surprising complexities. This guide documents the key lessons and quirks uncovered while building one.

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💥 Common Pitfalls & Gotchas

1. later=yes silently disables description

If your Pinboard URL includes later=yes, it will silently ignore the description field — no error, just no description saved.

✅ Fix:

• Do not use later=yes
• Use a window.open() popup instead, which allows the description to be preserved

window.open(pinURL, "Pinboard", "toolbar=no,width=700,height=350");

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2. Single-line comments break bookmarklets

Since bookmarklets are often pasted into a single-line input field (like the browser's bookmarks bar), using // will break the code.

✅ Fix:

Use block comments (/* ... */) only.

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3. DOM methods can fail silently

APIs like getElementsByClassName may return unexpected results due to dynamic content or page structure.

✅ Fix:

• Use document.querySelector() or document.querySelectorAll()
• Always check for null or undefined before accessing .textContent

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4. Use document.title for the bookmark title

Avoid parsing the title manually from page elements. document.title is reliable and already includes the paper ID.

var title = document.title;

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5. Always use encodeURIComponent

If any part of the Pinboard URL is unescaped, the whole request may break.

✅ Fix:

var esc = function (s) {
  return encodeURIComponent(s);
};

Use it for every URL component: url, title, description, tags, etc.

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6. Normalize and trim the abstract

Long descriptions are okay, but Pinboard fields should be clean:

✅ Tips:

• Strip the "Abstract:" prefix
• Collapse all whitespace
• trim() the final result

var desc = abs.textContent
  .replace(/^\s*Abstract:\s*/i, "")
  .replace(/\s+/g, " ")
  .trim();

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7. Debug with alert() during development

Pinboard gives zero feedback when fields are dropped or broken. Use alert() to confirm the final URL.

alert(pinURL);

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🧩 Data Extracted from arXiv

We were able to reliably extract:

Field	Method
Paper ID	Regex match from location.href
Authors	div.authors → normalized author:john_doe format
Subjects	td.tablecell.subjects → extract arXiv tags from parentheses
Year	div.dateline → 20XX year match
Title	From document.title
Abstract	From blockquote.abstract → normalized as description

---

✅ Final Notes

Writing Pinboard bookmarklets isn’t hard — until you care about quality:

• ✂️ Remove later=yes
• 📏 Don’t use // comments
• 🕵️ DOM is fickle — always check for nulls
• 🧼 Normalize everything
• 🚨 Alert before you open
• 💡 Use the popup!

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Made through trial, error, and a healthy amount of rebellion ⚔️

pin-arxiv.js

(function () {
  try {
    /* encode helper */
    var esc = function (s) {
      return encodeURIComponent(s);
    };

    /* arXiv ID */
    var url = location.href;
    var m = url.match(/arxiv\.org\/abs\/([\d\.]+)(v\d+)?/);
    var paper = m ? m[1] : "";

    /* Authors → ["author:..."] */
    var getAuthorTags = function () {
      var el = document.querySelector("div.authors");
      return el
        ? el.textContent
            .replace(/^Authors?:\s*/, "")
            .split(",")
            .map(function (s) {
              return "author:" + s.trim().toLowerCase().replace(/\s+/g, "_");
            })
        : [];
    };

    /* Subjects → ["subject:..."] */
    var getSubjectTags = function () {
      var el = document.querySelector("td.tablecell.subjects");
      return el
        ? (el.textContent.match(/\(([^)]+)\)/g) || []).map(function (s) {
            return "subject:" + s.slice(1, -1);
          })
        : [];
    };

    /* Year → "year:2025" */
    var getYearTag = function () {
      var el = document.querySelector("div.dateline");
      var m = el && el.textContent.match(/\b(20\d{2})\b/);
      return m ? "year:" + m[1] : "";
    };

    /* Abstract → "..." */
    var getDescription = function () {
      var el = document.querySelector("blockquote.abstract");
      return el
        ? el.textContent
            .replace(/^\s*Abstract:\s*/i, "")
            .replace(/\s+/g, " ")
            .trim()
        : "";
    };

    /* Title (via <title>) */
    var title = document.title;

    /* Assemble all tags */
    var tags = []
      .concat(
        "arxiv",
        paper ? ["paper:" + paper] : [],
        getAuthorTags(),
        getSubjectTags(),
        getYearTag() ? [getYearTag()] : [],
      )
      .join(" ");

    /* Pinboard URL (opens popup for description) */
    var pinURL =
      "https://pinboard.in/add?" +
      "url=" +
      esc(url) +
      "&title=" +
      esc(title) +
      "&description=" +
      esc(getDescription()) +
      "&tags=" +
      esc(tags);

    void window.open(pinURL, "Pinboard", "toolbar=no,width=700,height=350");
  } catch (e) {
    alert("pin-arxiv error: " + (e.message || e));
  }
})();

// Safer https://make-bookmarklets.com/ minified version.
// javascript:(function(){!function(){try{var t=function(t){return encodeURIComponent(t)},e=location.href,r=e.match(/arxiv\.org\/abs\/([\d\.]+)(v\d+)?/),n=r?r[1]:"",o=function(){var t=document.querySelector("div.dateline"),e=t&&t.textContent.match(/\b(20\d{2})\b/);return e?"year:"+e[1]:""},a=document.title,c=[].concat("arxiv",n?["paper:"+n]:[],(u=document.querySelector("div.authors"),u?u.textContent.replace(/^Authors?:\s*/,"").split(",").map((function(t){return"author:"+t.trim().toLowerCase().replace(/\s+/g,"_")})):[]),function(){var t=document.querySelector("td.tablecell.subjects");return t?(t.textContent.match(/\(([^)]+)\)/g)||[]).map((function(t){return"subject:"+t.slice(1,-1)})):[]}(),o()?[o()]:[]).join(" "),i="https://pinboard.in/add?url="+t(e)+"&title="+t(a)+"&description="+t(function(){var t=document.querySelector("blockquote.abstract");return t?t.textContent.replace(/^\s*Abstract:\s*/i,"").replace(/\s+/g," ").trim():""}())+"&tags="+t(c);window.open(i,"Pinboard","toolbar=no,width=700,height=350")}catch(t){alert("pin-arxiv error: "+(t.message||t))}var u}();}());