Leonardo Devai
b3326856db
Pinned 2026 toolchains (Go 1.26, Rust 1.98/edition 2024, Python 3.14 + uv, Node 24, Zig 0.16, NixOS 26.05), postgres 18 / mongo 8, lockfiles built from, non-root runtimes, .dockerignore, per-project LICENSE, READMEs with the git.devai.io clone line, checkout@v7 CI. Security fixes in the legacy Rust APIs (any-password login, self-assigned admin, hard-coded JWT secret), JWT alg/exp/sub enforcement across the blog series, safe markdown links in the frontends, and many smaller bugs — every project was built, run and exercised end to end. Adds scripts/publish.sh + a CI publish job that splits every folder into its own repo at git.devai.io/templates/<folder>. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01128fhuZbgivaSJvtMf4s1G
58 lines
1.8 KiB
Markdown
58 lines
1.8 KiB
Markdown
# tip-calculator
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A working tip calculator in one HTML file, one CSS file and about 30 lines
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of JavaScript. Type a bill, drag the tip slider, split it between friends — and
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learn the pattern behind almost every web page: read the inputs, do the math,
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write the answer back.
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## Run
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Get it: `git clone https://git.devai.io/templates/tip-calculator.git`
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Double-click `index.html` — it opens in your browser and works. Nothing to
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install, no build step.
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Or serve it like production:
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```sh
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docker compose up --build
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```
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Then open http://localhost:8080.
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## How it works
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The whole app is one function, `calculate()`: it reads the three inputs, works
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out the tip and the per-person total, and writes both back onto the page. One
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line makes it live:
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```js
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el.addEventListener("input", calculate);
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```
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"Whenever this input changes, run `calculate`." Everything else is plain
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JavaScript: `getElementById` finds an element, `parseFloat` turns typed text
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into a number, and the built-in `Intl.NumberFormat` turns `19.5` into `$19.50`.
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Try it: swap `"USD"` for `"EUR"` (and `"en-US"` for `"de-DE"`), add a
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"round up" checkbox, or raise the slider's `max="30"` for generous tippers.
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## Layout
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```
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index.html the inputs — each has an id so JavaScript can find it
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app.js calculate() and the listeners that run it
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styles.css the look; follows your system's light or dark mode
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```
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## Deploy
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Push to your own GitHub repo and the shipped workflow
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(`.github/workflows/ci.yml`) tests the compose stack, publishes the image to
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GHCR, and — once you set the `DEPLOY_HOST` / `DEPLOY_USER` variables and
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`DEPLOY_KEY` secret — deploys it to your server over ssh.
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---
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Part of [devai.io](https://devai.io) — the Web Basics track: HTML, CSS &
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JavaScript, one concept at a time. Next up:
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[todo-list](https://git.devai.io/templates/todo-list).
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