(Based on ${totalCalories} calories in ${portionSize.toFixed(1)} ${portionUnit})

`; downloadPdfButton.style.display = 'block'; // Store data for PDF report resultArea.dataset.totalCalories = totalCalories; resultArea.dataset.portionSize = portionSize; resultArea.dataset.portionUnit = portionUnit; resultArea.dataset.portionSizeInGrams = portionSizeInGrams.toFixed(2); resultArea.dataset.caloricDensity = caloricDensity.toFixed(2); resultArea.dataset.densityScore = densityScore; resultArea.dataset.densityInterpretation = densityInterpretation; } /** * Clears all inputs and results. */ function clearAll() { const totalCaloriesInput = document.getElementById('totalCaloriesInput'); const portionSizeInput = document.getElementById('portionSizeInput'); const portionUnitSelect = document.getElementById('portionUnitSelect'); const resultArea = document.getElementById('resultArea'); const downloadPdfButton = document.getElementById('downloadPdfButton'); const errorMessageDiv = document.getElementById('errorMessage'); if (totalCaloriesInput) { totalCaloriesInput.value = ''; } if (portionSizeInput) { portionSizeInput.value = ''; } if (portionUnitSelect) { portionUnitSelect.value = 'grams'; // Reset to default } if (resultArea) { resultArea.style.display = 'none'; resultArea.innerHTML = ''; // Clear stored data for PDF delete resultArea.dataset.totalCalories; delete resultArea.dataset.portionSize; delete resultArea.dataset.portionUnit; delete resultArea.dataset.portionSizeInGrams; delete resultArea.dataset.caloricDensity; delete resultArea.dataset.densityScore; delete resultArea.dataset.densityInterpretation; } if (downloadPdfButton) { downloadPdfButton.style.display = 'none'; } if (errorMessageDiv) { errorMessageDiv.style.display = 'none'; } } /** * Generates a PDF report of the Caloric Density calculation. */ function generatePdfReport() { try { // Check if jsPDF library is loaded if (typeof window.jspdf === 'undefined' || typeof window.jspdf.jsPDF === 'undefined') { console.error('jsPDF library not loaded. Cannot generate PDF.'); showMessage('PDF generation failed: jspdf library not loaded. Please try again or check your internet connection.', 'error'); return; } const { jsPDF } = window.jspdf; const doc = new jsPDF(); const resultArea = document.getElementById('resultArea'); // Retrieve stored data const totalCalories = resultArea.dataset.totalCalories || 'N/A'; const portionSize = resultArea.dataset.portionSize || 'N/A'; const portionUnit = resultArea.dataset.portionUnit || 'N/A'; const portionSizeInGrams = resultArea.dataset.portionSizeInGrams || 'N/A'; const caloricDensity = resultArea.dataset.caloricDensity || 'N/A'; const densityScore = resultArea.dataset.densityScore || 'N/A'; const densityInterpretation = resultArea.dataset.densityInterpretation || 'N/A'; const generationDate = new Date().toLocaleString(); if (totalCalories === 'N/A') { showMessage('No calculation data available to generate a PDF. Please calculate caloric density first.', 'info'); return; } let yOffset = 20; // Title doc.setFontSize(22); doc.setTextColor(44, 62, 80); doc.text("Caloric Density Report", 105, yOffset, { align: 'center' }); yOffset += 15; // Date Generated doc.setFontSize(10); doc.setTextColor(100, 100, 100); doc.text(`Report Generated: ${generationDate}`, 105, yOffset, { align: 'center' }); yOffset += 20; // Input Details doc.setFontSize(14); doc.setTextColor(51, 51, 51); doc.text(`Input Calories: ${totalCalories} kcal`, 20, yOffset); yOffset += 10; doc.text(`Input Portion Size: ${portionSize} ${portionUnit}`, 20, yOffset); yOffset += 10; doc.text(`Portion Size (in grams): ${portionSizeInGrams} g`, 20, yOffset); yOffset += 20; // Result Section doc.setFontSize(16); doc.setTextColor(46, 204, 113); /* Green */ doc.text("Calculated Caloric Density:", 20, yOffset); yOffset += 10; doc.setFontSize(24); doc.text(`${caloricDensity} kcal/gram`, 25, yOffset); yOffset += 15; doc.setFontSize(16); doc.text(`Density Score: ${densityScore}`, 20, yOffset); yOffset += 10; doc.setFontSize(12); const interpretationLines = doc.splitTextToSize(densityInterpretation, 170); doc.text(interpretationLines, 25, yOffset); yOffset += (interpretationLines.length * 7) + 15; // Explanation of Caloric Density doc.setFontSize(12); doc.setTextColor(80, 80, 80); doc.text("Understanding Caloric Density:", 20, yOffset); yOffset += 7; const explanationText = "Caloric density refers to the number of calories in a given weight of food. Foods with high caloric density provide more calories for the same weight, while those with low caloric density provide fewer. This concept is useful for understanding how different foods contribute to your overall energy intake."; const splitExplanation = doc.splitTextToSize(explanationText, 170); doc.text(splitExplanation, 25, yOffset); yOffset += (splitExplanation.length * 7) + 15; // Thresholds Table doc.setFontSize(12); doc.text("Caloric Density Score Thresholds (kcal/gram):", 20, yOffset); yOffset += 10; const tableData = [ ["Score", "Caloric Density (kcal/gram)", "Description"], ["Low", `< ${CALORIC_DENSITY_THRESHOLDS.LOW}`, "Often rich in water and fiber, promotes fullness with fewer calories."], ["Medium", `${CALORIC_DENSITY_THRESHOLDS.LOW} - ${CALORIC_DENSITY_THRESHOLDS.MEDIUM}`, "Moderate energy content."], ["High", `> ${CALORIC_DENSITY_THRESHOLDS.MEDIUM}`, "Often high in fat, providing more calories in a smaller portion."] ]; doc.autoTable({ startY: yOffset, head: [tableData[0]], body: tableData.slice(1), theme: 'grid', styles: { fontSize: 9, cellPadding: 2, fillColor: [255, 255, 255] }, headStyles: { fillColor: [209, 236, 241], textColor: [12, 84, 96], fontStyle: 'bold', halign: 'center' }, alternateRowStyles: { fillColor: [242, 242, 242] }, columnStyles: { 0: { halign: 'center' }, 1: { halign: 'center' }, 2: { halign: 'left', cellWidth: 90 } }, margin: { left: 20, right: 20 }, didDrawPage: function(data) { // Footer for each page doc.setFontSize(8); doc.setTextColor(150, 150, 150); doc.text(`Page ${doc.internal.getNumberOfPages()}`, doc.internal.pageSize.width - 20, doc.internal.pageSize.height - 10, { align: 'right' }); doc.text("Portion Size to Caloric Density Score Converter", 20, doc.internal.pageSize.height - 10); } }); // Final footer for the last page if not already drawn by autoTable if (doc.autoTable.previous.finalY < doc.internal.pageSize.height - 25) { doc.setFontSize(9); doc.setTextColor(150, 150, 150); doc.text(`Report Generated: ${generationDate}`, 20, doc.internal.pageSize.height - 15); doc.text("Portion Size to Caloric Density Score Converter", doc.internal.pageSize.width - 20, doc.internal.pageSize.height - 15, { align: 'right' }); } doc.save("Caloric_Density_Report.pdf"); } catch (error) { console.error('Error generating PDF:', error); showMessage(`PDF generation failed: ${error.message}. Please check your browser's console for more details.`, 'error'); } }