tools/image-alt-text-extractor.html at main · mathspp/tools · GitHub

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<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Image Alt Text Extractor</title>
    <link rel="stylesheet" href="styles.css">
    <style>
        body {
            max-width: 960px;
            margin: 0 auto;
            padding: 24px 20px 48px;
        }

        .page-header {
            display: flex;
            flex-direction: column;
            gap: 0.5rem;
        }

        .site-link {
            font-weight: 600;
            color: var(--foreground-subtle);
            text-decoration: none;
        }

        .site-link:hover,
        .site-link:focus-visible {
            color: var(--foreground);
        }

        main {
            display: grid;
            gap: 1.25rem;
        }

        .panel {
            padding: clamp(1.25rem, 3vw, 2rem);
        }

        .input-grid {
            display: grid;
            gap: 1rem;
        }

        .drop-zone {
            border: 2px dashed var(--color-border, #d0d7de);
            border-radius: 12px;
            padding: 28px 18px;
            text-align: center;
            cursor: pointer;
            transition: border-color 0.2s ease, background-color 0.2s ease;
        }

        .drop-zone.dragover {
            border-color: var(--color-accent, #0070f3);
            background-color: rgba(0, 112, 243, 0.08);
        }

        .drop-zone:focus-visible {
            outline: 2px solid var(--color-accent, #0070f3);
            outline-offset: 2px;
        }

        .drop-zone input[type="file"] {
            display: none;
        }

        .status-text {
            color: var(--color-muted, #57606a);
            min-height: 1.25rem;
        }

        .status-text.error {
            color: #b42318;
        }

        .preview-wrapper {
            display: grid;
            gap: 0.75rem;
        }

        .preview-wrapper img {
            max-width: 100%;
            border-radius: 10px;
            background: #fff;
            box-shadow: 0 2px 10px rgba(15, 23, 42, 0.08);
        }

        .alt-text-area {
            width: 100%;
            min-height: 120px;
            resize: vertical;
        }

        .badge {
            display: inline-flex;
            align-items: center;
            gap: 0.35rem;
            padding: 0.25rem 0.6rem;
            border-radius: 999px;
            background: var(--background-elevated, #f6f8fa);
            color: var(--foreground-muted, #57606a);
            font-size: 0.95rem;
            width: fit-content;
        }

        .info-row {
            display: flex;
            flex-wrap: wrap;
            gap: 0.75rem;
            align-items: center;
        }

        .tool-actions {
            display: flex;
            flex-wrap: wrap;
            gap: 0.75rem;
        }

        @media (max-width: 720px) {
            body {
                padding: 20px 16px 40px;
            }
        }
    </style>
</head>

<body>
    <header class="page-header">
        <a class="site-link" href="https://tools.mathspp.com/" aria-label="Back to tools.mathspp.com">← tools.mathspp.com</a>
        <h1>Image Alt Text Extractor</h1>
        <p class="lead">Paste or drop an image and we will surface any ALT text that came with it. If none is present, we will tell you.</p>
    </header>

    <main>
        <section class="surface panel">
            <div class="input-grid">
                <label class="drop-zone" id="drop-zone" tabindex="0" aria-label="Paste or drop an image here">
                    <strong>Paste, drop, or select an image</strong>
                    <p class="status-text" id="drop-hint">Drop a file, press Ctrl/Cmd+V, or use the buttons below.</p>
                    <input type="file" id="file-input" accept="image/*">
                </label>
                <div class="tool-actions">
                    <button type="button" id="clipboard-button">Paste image from clipboard</button>
                    <button type="button" id="file-button">Choose an image</button>
                </div>
                <p class="status-text" id="status" aria-live="polite">No image loaded yet.</p>
            </div>
        </section>

        <section class="surface panel" aria-live="polite">
            <div class="info-row" aria-hidden="true" id="info-row" hidden>
                <span class="badge" id="image-info"></span>
            </div>
            <div class="preview-wrapper">
                <div class="form-group">
                    <label for="alt-text">ALT text found</label>
                    <textarea id="alt-text" class="alt-text-area" placeholder="ALT text will appear here" spellcheck="true"></textarea>
                </div>
                <div class="tool-actions">
                    <button type="button" id="copy-button">Copy ALT text</button>
                    <button type="button" id="clear-button">Clear</button>
                </div>
                <img id="preview" alt="Preview of the pasted image" hidden>
            </div>
        </section>
    </main>

    <script>
        const dropZone = document.getElementById('drop-zone');
        const fileInput = document.getElementById('file-input');
        const clipboardButton = document.getElementById('clipboard-button');
        const fileButton = document.getElementById('file-button');
        const statusEl = document.getElementById('status');
        const previewEl = document.getElementById('preview');
        const altTextEl = document.getElementById('alt-text');
        const copyButton = document.getElementById('copy-button');
        const clearButton = document.getElementById('clear-button');
        const dropHint = document.getElementById('drop-hint');
        const infoRow = document.getElementById('info-row');
        const imageInfo = document.getElementById('image-info');

        let lastObjectUrl = null;

        function setStatus(message, isError = false) {
            statusEl.textContent = message;
            statusEl.classList.toggle('error', isError);
        }

        function resetPreview() {
            previewEl.src = '';
            previewEl.hidden = true;
            altTextEl.value = '';
            infoRow.hidden = true;
            if (lastObjectUrl) {
                URL.revokeObjectURL(lastObjectUrl);
                lastObjectUrl = null;
            }
            setStatus('No image loaded yet.');
        }

        function describeImage(file) {
            const sizeKb = file.size / 1024;
            const kbDisplay = sizeKb >= 1024 ? `${(sizeKb / 1024).toFixed(1)} MB` : `${sizeKb.toFixed(0)} kB`;
            imageInfo.textContent = `${file.name || 'clipboard image'} • ${kbDisplay}`;
            infoRow.hidden = false;
        }

        function extractAltFromHtml(html) {
            if (!html) return '';
            try {
                const parser = new DOMParser();
                const doc = parser.parseFromString(html, 'text/html');
                const img = doc.querySelector('img[alt]');
                return img?.getAttribute('alt')?.trim() || '';
            } catch (error) {
                console.error('Failed to parse HTML clipboard content', error);
                return '';
            }
        }

        function handleImage(file, altText, sourceDescription) {
            describeImage(file);
            const objectUrl = URL.createObjectURL(file);
            if (lastObjectUrl) {
                URL.revokeObjectURL(lastObjectUrl);
            }
            lastObjectUrl = objectUrl;
            previewEl.src = objectUrl;
            previewEl.hidden = false;
            altTextEl.value = altText || '';
            if (altText) {
                setStatus(`ALT text found from ${sourceDescription}.`);
            } else {
                setStatus('No ALT text found for this image.', true);
            }
        }

        async function handleClipboardRead() {
            if (!navigator.clipboard?.read) {
                setStatus('Clipboard image reading is not supported in this browser.', true);
                return;
            }
            try {
                setStatus('Reading clipboard…');
                const items = await navigator.clipboard.read();

                let html = '';
                let imageBlob = null;

                for (const item of items) {
                    if (!html && item.types.includes('text/html')) {
                        const blob = await item.getType('text/html');
                        html = await blob.text();
                    }
                    const imageType = item.types.find(type => type.startsWith('image/'));
                    if (!imageBlob && imageType) {
                        imageBlob = await item.getType(imageType);
                        imageBlob.name = 'clipboard-image';
                    }
                }

                if (!imageBlob) {
                    setStatus('No image found in clipboard.', true);
                    return;
                }

                const altText = extractAltFromHtml(html);
                handleImage(imageBlob, altText, 'clipboard metadata');
            } catch (error) {
                console.error(error);
                setStatus('Failed to read clipboard image or metadata. The browser may have blocked access.', true);
            }
        }

        function handlePasteEvent(event) {
            const file = [...event.clipboardData.files].find(item => item.type.startsWith('image/'));
            const html = event.clipboardData.getData('text/html');
            const altText = extractAltFromHtml(html);

            if (file) {
                event.preventDefault();
                handleImage(file, altText, 'clipboard metadata');
            } else if (altText) {
                altTextEl.value = altText;
                setStatus('ALT text found in clipboard HTML, but no image was included.');
            } else {
                setStatus('Clipboard does not contain an image or ALT metadata.', true);
            }
        }

        function handleFileInput(file, sourceDescription) {
            if (!file || !file.type.startsWith('image/')) {
                setStatus('Please provide an image file.', true);
                return;
            }
            handleImage(file, '', sourceDescription);
        }

        dropZone.addEventListener('dragover', (event) => {
            event.preventDefault();
            dropZone.classList.add('dragover');
        });

        dropZone.addEventListener('dragleave', () => {
            dropZone.classList.remove('dragover');
        });

        dropZone.addEventListener('drop', (event) => {
            event.preventDefault();
            dropZone.classList.remove('dragover');
            const [file] = event.dataTransfer.files;
            handleFileInput(file, 'drag and drop');
        });

        dropZone.addEventListener('click', () => fileInput.click());

        dropZone.addEventListener('keydown', (event) => {
            if (event.key === 'Enter' || event.key === ' ') {
                event.preventDefault();
                fileInput.click();
            }
        });

        dropZone.addEventListener('paste', handlePasteEvent);

        fileInput.addEventListener('change', (event) => {
            const [file] = event.target.files;
            handleFileInput(file, 'file picker');
            fileInput.value = '';
        });

        fileButton.addEventListener('click', () => fileInput.click());

        clipboardButton.addEventListener('click', handleClipboardRead);

        copyButton.addEventListener('click', async () => {
            if (!altTextEl.value.trim()) {
                setStatus('Nothing to copy yet.', true);
                return;
            }
            try {
                await navigator.clipboard.writeText(altTextEl.value.trim());
                setStatus('ALT text copied to clipboard.');
            } catch (error) {
                console.error(error);
                setStatus('Unable to copy ALT text.', true);
            }
        });

        clearButton.addEventListener('click', () => {
            resetPreview();
        });

        dropHint.textContent = navigator.clipboard?.read ? 'Drop a file, press Ctrl/Cmd+V, or use the buttons below.' : 'Drop a file or use the choose image button.';
        setStatus('No image loaded yet.');
    </script>

    <footer class="page-footer">
        <p>Built with ❤️, 🤖, and 🐍, by <a href="https://mathspp.com/">Rodrigo Girão Serrão</a></p>
    </footer>
</body>

</html>