convert json to form data javascript

<div class="container">
        <h1>JSON to FormData Converter</h1>
        
        <div class="input-section">
            <label for="jsonInput">Enter JSON Object:</label>
            <textarea id="jsonInput" placeholder='{"name": "John", "email": "john@example.com", "age": 30}'></textarea>
        </div>

        <div class="button-group">
            <button onclick="convertToFormData()">Convert to FormData</button>
            <button onclick="clearAll()">Clear</button>
        </div>

        <div class="output-section">
            <div class="output-title">FormData Entries:</div>
            <div class="output-content" id="output">
                <div style="color: #666; text-align: center; padding: 20px;">
                    Enter JSON and click Convert
                </div>
            </div>
        </div>
    </div>

  * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(135deg, #0a0a0a 0%, #1a1a1a 50%, #0f0f0f 100%);
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
            color: #e0e0e0;
        }

        .container {
            width: 100%;
            max-width: 900px;
            background: linear-gradient(145deg, #1a1a1a, #0d0d0d);
            border-radius: 16px;
            padding: 40px;
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
            border: 1px solid #2a2a2a;
        }

        h1 {
            text-align: center;
            margin-bottom: 30px;
            font-size: 28px;
            background: linear-gradient(135deg, #ffffff, #888888);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .input-section {
            margin-bottom: 25px;
        }

        label {
            display: block;
            margin-bottom: 10px;
            font-weight: 500;
            color: #b0b0b0;
            font-size: 14px;
            text-transform: uppercase;
            letter-spacing: 1px;
        }

        textarea {
            width: 100%;
            min-height: 200px;
            padding: 15px;
            background: #0a0a0a;
            border: 1px solid #333;
            border-radius: 8px;
            color: #e0e0e0;
            font-family: 'Courier New', monospace;
            font-size: 14px;
            resize: vertical;
            transition: border-color 0.3s;
        }

        textarea:focus {
            outline: none;
            border-color: #555;
        }

        .button-group {
            display: flex;
            gap: 15px;
            margin-bottom: 25px;
        }

        button {
            flex: 1;
            padding: 14px 24px;
            background: linear-gradient(135deg, #2a2a2a, #1a1a1a);
            color: #ffffff;
            border: 1px solid #3a3a3a;
            border-radius: 8px;
            font-size: 15px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s;
            text-transform: uppercase;
            letter-spacing: 0.5px;
        }

        button:hover {
            background: linear-gradient(135deg, #3a3a3a, #2a2a2a);
            border-color: #4a4a4a;
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
        }

        button:active {
            transform: translateY(0);
        }

        .output-section {
            background: #0a0a0a;
            border: 1px solid #2a2a2a;
            border-radius: 8px;
            padding: 20px;
            min-height: 150px;
        }

        .output-title {
            font-size: 14px;
            color: #b0b0b0;
            margin-bottom: 15px;
            text-transform: uppercase;
            letter-spacing: 1px;
        }

        .output-content {
            background: #050505;
            padding: 15px;
            border-radius: 6px;
            border: 1px solid #1a1a1a;
            max-height: 300px;
            overflow-y: auto;
        }

        .output-item {
            padding: 8px 0;
            border-bottom: 1px solid #1a1a1a;
            font-family: 'Courier New', monospace;
            font-size: 13px;
        }

        .output-item:last-child {
            border-bottom: none;
        }

        .key {
            color: #7aa2f7;
            font-weight: 600;
        }

        .value {
            color: #9ece6a;
        }

        .error {
            color: #f7768e;
            padding: 12px;
            background: rgba(247, 118, 142, 0.1);
            border-radius: 6px;
            border: 1px solid rgba(247, 118, 142, 0.3);
        }

        .success {
            color: #9ece6a;
            padding: 12px;
            background: rgba(158, 206, 106, 0.1);
            border-radius: 6px;
            border: 1px solid rgba(158, 206, 106, 0.3);
        }

        ::-webkit-scrollbar {
            width: 8px;
        }

        ::-webkit-scrollbar-track {
            background: #0a0a0a;
        }

        ::-webkit-scrollbar-thumb {
            background: #2a2a2a;
            border-radius: 4px;
        }

        ::-webkit-scrollbar-thumb:hover {
            background: #3a3a3a;
        }

  function convertToFormData() {
            const input = document.getElementById('jsonInput').value.trim();
            const output = document.getElementById('output');

            if (!input) {
                output.innerHTML = '<div class="error">Please enter a JSON object</div>';
                return;
            }

            try {
                const jsonData = JSON.parse(input);
                const formData = new FormData();

                // Function to handle nested objects and arrays
                function appendFormData(data, parentKey = '') {
                    if (data && typeof data === 'object' && !(data instanceof File)) {
                        if (Array.isArray(data)) {
                            data.forEach((item, index) => {
                                const key = parentKey ? `${parentKey}[${index}]` : `${index}`;
                                appendFormData(item, key);
                            });
                        } else {
                            Object.keys(data).forEach(key => {
                                const value = data[key];
                                const formKey = parentKey ? `${parentKey}[${key}]` : key;
                                appendFormData(value, formKey);
                            });
                        }
                    } else {
                        formData.append(parentKey, data);
                    }
                }

                appendFormData(jsonData);

                // Display the FormData entries
                let html = '<div class="success">✓ Successfully converted to FormData</div>';
                let count = 0;

                for (let [key, value] of formData.entries()) {
                    count++;
                    html += `
                        <div class="output-item">
                            <span class="key">${escapeHtml(key)}</span>: 
                            <span class="value">${escapeHtml(String(value))}</span>
                        </div>
                    `;
                }

                if (count === 0) {
                    html += '<div class="error">No entries found in JSON</div>';
                }

                output.innerHTML = html;

            } catch (e) {
                output.innerHTML = `<div class="error">Invalid JSON: ${escapeHtml(e.message)}</div>`;
            }
        }

        function clearAll() {
            document.getElementById('jsonInput').value = '';
            document.getElementById('output').innerHTML = '<div style="color: #666; text-align: center; padding: 20px;">Enter JSON and click Convert</div>';
        }

        function escapeHtml(text) {
            const map = {
                '&': '&amp;',
                '<': '&lt;',
                '>': '&gt;',
                '"': '&quot;',
                "'": '&#039;'
            };
            return text.replace(/[&<>"']/g, m => map[m]);
        }

        // Example data on load
        window.addEventListener('load', () => {
            document.getElementById('jsonInput').value = JSON.stringify({
                name: "John Doe",
                email: "john@example.com",
                age: 30,
                hobbies: ["reading", "coding"],
                address: {
                    street: "123 Main St",
                    city: "New York"
                }
            }, null, 2);
        });