Invoice Generation Showcase Demo Code Sample

1// ES6 Compliant Syntax
2// GitHub Copilot - GPT-4 Model - October 14, 2025
3// File: invoice-generation/index.js
4
5// Global variables
6const element = document.getElementById('viewer');
7let documentViewer = null;
8let sampleData = {};
9let templateApplied = false;
10const defaultDoc = 'https://apryse.s3.us-west-1.amazonaws.com/public/files/samples/invoice_template.docx';
11
12// Initialize WebViewer
13WebViewer({
14  path: '/lib',
15  licenseKey: 'YOUR_LICENSE_KEY',
16}, element).then((instance) => {
17  documentViewer = instance.Core.documentViewer;
18  loadTemplateDocument(); // Load the default template document, initialize sample data and generate input fields
19});
20
21// Load default template document and initialize sample data
22const loadTemplateDocument = async () => {
23  // Load DOCX template
24  await documentViewer.loadDocument(defaultDoc, {extension: 'docx'});
25  templateApplied = false;
26  // Initialize sample data
27  sampleData = {
28    invoice_number: '3467821',
29    bill_to_name: 'Victoria Guti\u00e9rrez',
30    ship_to_name: 'Mar\u00eda Rosales',
31    items: [
32        { description: 'Item 1', qty: '1', price: '10.00', total: '10.00' },
33        { description: 'Item 2', qty: '20', price: '20.00', total: '400.00' },
34        { description: 'Item 3', qty: '1', price: '0.00', total: '0.00' },
35        { description: 'Item 4', qty: '1', price: '0.00', total: '0.00' },
36    ],
37    subtotal: '410.00',
38    sales_tax_rate: '5.0%',
39    sales_t: '20.50',
40    total_t: '500.00',
41  };
42  generateInputFields(); // Generate input fields based on default sampleData values
43};
44
45const fillTemplate = async () => {
46  // Update sampleData from the input field values
47  // Each field is identified by its unique ID
48  // The ID was originally generated from sampleData key for the fixed fields, or from (key, index, subKey) for array items
49  Object.keys(sampleData).forEach(key => {
50    if (Array.isArray(sampleData[key])) {
51      // array field items
52      sampleData[key].forEach((item, index) => {
53        Object.keys(item).forEach(subKey => {
54          const input = document.getElementById(`${key}_${index}_${subKey}`.toLowerCase());
55          sampleData[key][index][subKey] = input.value;
56        });
57      });
58    }
59    else {
60      // non-array (fixed) fields
61      const input = document.getElementById(key.toLowerCase());
62      sampleData[key] = input.value;
63    }
64  });
65  // Apply JSON data to the PDF
66  if(templateApplied) // reload the template document if it has already been applied
67    await documentViewer.loadDocument(defaultDoc, {extension: 'docx'});
68  await documentViewer.getDocument().applyTemplateValues(sampleData);
69  templateApplied = true;
70};
71
72// Generate input fields based on the sampleData structure
73// The left div contains the fixed text inputs for non-array fields
74// The right div contains the dynamic text inputs for array fields (items).
75// Each array item corresponds to a row in the table (loop in the template)
76const generateInputFields = () => {
77  // clear previous controls from the 2 divs
78  leftDiv.innerHTML = rightDiv.innerHTML = '';  
79  Object.keys(sampleData).forEach(key => {
80    if (Array.isArray(sampleData[key])) {
81      // array field - create multiple text inputs for each item in the array in the right div
82      sampleData[key].forEach((item, index) => {
83        // create a header row before the first row
84        if (index === 0) {
85          Object.keys(item).forEach(subKey => {
86            const desc = document.createElement('input');
87            desc.type = 'text';
88            desc.disabled = true;
89            desc.value = subKey || '';
90            rightDiv.appendChild(desc);
91          });
92        rightDiv.appendChild(document.createElement('br'));
93        }
94        // create the rows that correspond to each item in the array
95        Object.keys(item).forEach(subKey => {
96          const input = document.createElement('input');
97          // generate a unique ID for each input based on the key, index, and subKey
98          input.id = `${key}_${index}_${subKey}`.toLowerCase();
99          input.type = 'text';
100          input.value = item[subKey] || '';
101          rightDiv.appendChild(input);
102        });
103        // add a delete button for each row
104        const deleteButton = document.createElement('button');
105        deleteButton.textContent = '\u2716'; // Unicode for '✖' symbol
106        deleteButton.className = 'btn-delete';
107        deleteButton.onclick = () => {
108          sampleData[key].splice(index, 1);
109          generateInputFields(); // regenerate the input fields to reflect the deletion
110        }
111        rightDiv.appendChild(deleteButton);
112        rightDiv.appendChild(document.createElement('br'));
113      });
114    }
115    else {  // create text input for each field in the left div
116      const desc = document.createElement('input');
117      desc.disabled = true;
118      desc.type = 'text';
119      desc.value = key + ': ';
120      leftDiv.appendChild(desc);
121      const input = document.createElement('input');
122      input.type = 'text';
123      input.value = sampleData[key] || '';
124      // use the key as the ID for easy lookup later
125      input.id = key.toLowerCase();
126      leftDiv.appendChild(input);
127      leftDiv.appendChild(document.createElement('br'));
128    }
129  });
130  // create a button to add a new item to the items array
131  const addRowButton = document.createElement('button');
132  addRowButton.textContent = 'Add Row';
133  addRowButton.className = 'btn';
134  addRowButton.onclick = () => {
135    const randQty = Math.floor(Math.random() * 20) + 1;
136    sampleData.items.push({ description: `Item ${sampleData.items.length + 1}`, qty: randQty.toString(), price: '0.00', total: '0.00' });
137    generateInputFields(); // regenerate the input fields to reflect the new row
138  };
139  addRowButton.disabled = sampleData.items.length >= 10; // limit to 10 items
140  rightDiv.appendChild(addRowButton);
141}
142
143// UI section
144
145// Create a container for the controls
146const controlsContainer = document.createElement('div');
147
148// Create 2 divs inside the container for left and right sections
149const leftDiv = document.createElement('div');
150const rightDiv = document.createElement('div');
151leftDiv.className = rightDiv.className = 'vertical-container'; // side-by-side divs using (display: inline-block) and (vertical-align: top)
152leftDiv.style.width = "40%";
153rightDiv.style.width = "60%"; // right div is wider to accommodate table rows
154controlsContainer.appendChild(leftDiv);
155controlsContainer.appendChild(rightDiv);
156
157const fillInvoiceButton = document.createElement('button');
158fillInvoiceButton.className = 'btn';
159fillInvoiceButton.textContent = 'Fill Template';
160fillInvoiceButton.onclick = async () => {
161  await fillTemplate(); // generate the invoice by filling the template with data
162};
163controlsContainer.appendChild(fillInvoiceButton);
164
165const resetDocumentButton = document.createElement('button');
166resetDocumentButton.className = 'btn';
167resetDocumentButton.textContent = '🗘 Reset Document';
168resetDocumentButton.onclick = async () => {
169  await loadTemplateDocument(); // reset document, data and input fields
170};
171controlsContainer.appendChild(resetDocumentButton);
172element.insertBefore(controlsContainer, element.firstChild);
173