excelize-wasm

You can control how a worksheet is scaled for printing using SetSheetProps and SetPageLayout. There are four common scaling presets:

1. No Scaling (Actual size): Set FitToPage: false via SetSheetProps.

2. Fit Sheet on One Page (Shrink to fit one page): Set FitToPage: true via SetSheetProps.

3. Fit All Columns on One Page (One page wide): Set FitToPage: true via SetSheetProps and set FitToHeight: 0 via SetPageLayout.

4. Fit All Rows on One Page (One page high): Set FitToPage: true via SetSheetProps and set FitToWidth: 0 via SetPageLayout.

// 1. No Scaling
const { error } = f.SetSheetProps('Sheet1', {
  FitToPage: false,
});

// 2. Fit Sheet on One Page
const { error } = f.SetSheetProps('Sheet1', { FitToPage: true });

// 3. Fit All Columns on One Page
let { error } = f.SetSheetProps('Sheet1', { FitToPage: true });
({ error } = f.SetPageLayout('Sheet1', { FitToHeight: 0 }));

// 4. Fit All Rows on One Page
let { error } = f.SetSheetProps('Sheet1', { FitToPage: true });
({ error } = f.SetPageLayout('Sheet1', { FitToWidth: 0 }));

To read an existing file, use excelize.OpenReader(buffer) where buffer is the file content (e.g., from fs.readFileSync).

Key methods for reading:

• GetCellValue(sheet, cell): Retrieves the value of a specific cell. Returns an object with { value, error }.
• GetRows(sheet): Retrieves all rows in a sheet. Returns an object with { result, error }, where result is an array of arrays representing rows and columns.

const { init } = require('excelize-wasm');
const fs = require('fs');

init('./node_modules/excelize-wasm/excelize.wasm.gz').then((excelize) => {
  const f = excelize.OpenReader(fs.readFileSync('Book1.xlsx'));
  if (f.error) {
    console.log(f.error);
    return;
  }
  // Get cell value
  const ret1 = f.GetCellValue('Sheet1', 'B2');
  if (ret1.error) {
    console.log(ret1.error);
    return;
  }
  console.log(ret1.value);

  // Get all rows
  const ret2 = f.GetRows('Sheet1');
  if (ret2.error) {
    console.log(ret2.error);
    return;
  }
  ret2.result.forEach((row) => {
    row.forEach((colCell) => {
      process.stdout.write(`${colCell}\t`);
    });
    console.log();
  });
});

You can generate charts based on worksheet data using f.AddChart(sheet, cell, options).

Key Options:

• Type: The chart type (e.g., excelize.Col3DClustered).
• Series: An array of objects defining Name, Categories, and Values (using Excel-style range strings like Sheet1!$B$1:$D$1).
• Title: An object containing Paragraph information for the chart title.

Example

const ret3 = f.AddChart('Sheet1', 'E1', {
  Type: excelize.Col3DClustered,
  Series: [
    {
      Name: 'Sheet1!$A$2',
      Categories: 'Sheet1!$B$1:$D$1',
      Values: 'Sheet1!$B$2:$D$2',
    },
    // ... more series
  ],
  Title: { Paragraph: [{ Text: 'Fruit 3D Clustered Column Chart' }] },
});

const { init } = require('excelize-wasm');
const fs = require('fs');

init('./node_modules/excelize-wasm/excelize.wasm.gz').then((excelize) => {
  const f = excelize.NewFile();
  if (f.error) {
    console.log(f.error);
    return;
  }
  [
    [null, 'Apple', 'Orange', 'Pear'],
    ['Small', 2, 3, 3],
    ['Normal', 5, 2, 4],
    ['Large', 6, 7, 8],
  ].forEach((row, idx) => {
    const ret1 = excelize.CoordinatesToCellName(1, idx + 1);
    if (ret1.error) {
      console.log(ret1.error);
      return;
    }
    const res2 = f.SetSheetRow('Sheet1', ret1.cell, row);
    if (res2.error) {
      console.log(res2.error);
      return;
    }
  });
  const ret3 = f.AddChart('Sheet1', 'E1', {
    Type: excelize.Col3DClustered,
    Series: [
      {
        Name: 'Sheet1!$A$2',
        Categories: 'Sheet1!$B$1:$D$1',
        Values: 'Sheet1!$B$2:$D$2',
      },
      {
        Name: 'Sheet1!$A$3',
        Categories: 'Sheet1!$B$1:$D$1',
        Values: 'Sheet1!$B$3:$D$3',
      },
      {
        Name: 'Sheet1!$A$4',
        Categories: 'Sheet1!$B$1:$D$1',
        Values: 'Sheet1!$B$4:$D$4',
      },
    ],
    Title: { Paragraph: [{ Text: 'Fruit 3D Clustered Column Chart' }] },
  });
  if (ret3.error) {
    console.log(ret3.error);
    return;
  }
  // Save spreadsheet by the given path.
  const { buffer, error } = f.WriteToBuffer();
  if (error) {
    console.log(error);
    return;
  }
  fs.writeFile('Book1.xlsx', buffer, 'binary', (error) => {
    if (error) {
      console.log(error);
    }
  });
});

To read an existing spreadsheet, use excelize.OpenReader(buffer) where buffer is the file content as a byte array. You can then retrieve cell values using GetCellValue or entire rows using GetRows.

Node.js Example

const { init } = require('excelize-wasm');
const fs = require('fs');

init('./node_modules/excelize-wasm/excelize.wasm.gz').then((excelize) => {
  const f = excelize.OpenReader(fs.readFileSync('Book1.xlsx'));
  if (f.error) {
    console.log(f.error);
    return;
  }
  // Get value of a cell.
  const ret1 = f.GetCellValue('Sheet1', 'B2');
  if (ret1.error) {
    console.log(ret1.error);
    return;
  }
  console.log(ret1.value);

  // Get all the rows in the Sheet1.
  const ret2 = f.GetRows('Sheet1');
  if (ret2.error) {
    console.log(ret2.error);
    return;
  }
  ret2.result.forEach((row) => {
    row.forEach((colCell) => {
      process.stdout.write(`${colCell}\t`);
    });
    console.log();
  });
});

Use excelize.NewFile() to create a new workbook. You can then add sheets with NewSheet(name), set cell values with SetCellValue(sheet, cell, value), and set the active sheet with SetActiveSheet(index). To save the workbook, use WriteToBuffer() to get the file contents as a buffer.

const { init } = require('excelize-wasm');
const fs = require('fs');

init('./node_modules/excelize-wasm/excelize.wasm.gz').then((excelize) => {
  const f = excelize.NewFile();
  if (f.error) {
    console.log(f.error);
    return;
  }
  // Create a new sheet
  const { index } = f.NewSheet('Sheet2');
  // Set cell values
  f.SetCellValue('Sheet2', 'A2', 'Hello world.');
  f.SetCellValue('Sheet1', 'B2', 100);
  // Set default sheet
  f.SetActiveSheet(index);
  // Save to buffer
  const { buffer, error } = f.WriteToBuffer();
  if (error) {
    console.log(error);
    return;
  }
  fs.writeFile('Book1.xlsx', buffer, 'binary', (error) => {
    if (error) console.log(error);
  });
});

Use f.AddPictureFromBytes(sheet, cell, options) to insert images.

Options include:

• Extension: The file extension (e.g., '.png', '.jpg', '.gif').
• File: The image data as a buffer/Uint8Array.
• Format: An object containing:
  • AltText: Alternative text for the image.
  • ScaleX, ScaleY: Scaling factors (e.g., 0.5).
  • OffsetX, OffsetY: Pixel offsets.
  • PrintObject: Boolean indicating if the image should be printed.
  • LockAspectRatio: Boolean to lock the aspect ratio.
  • Locked: Boolean to lock the image position/size.

const { init } = require('excelize-wasm');
const fs = require('fs');

init('./node_modules/excelize-wasm/excelize.wasm.gz').then((excelize) => {
  const f = excelize.OpenReader(fs.readFileSync('Book1.xlsx'));
  if (f.error) {
    console.log(f.error);
    return;
  }

  // Insert picture with scaling
  const ret2 = f.AddPictureFromBytes('Sheet1', 'D2', {
    Extension: '.jpg',
    File: fs.readFileSync('image.jpg'),
    Format: { AltText: 'Picture 2', ScaleX: 0.5, ScaleY: 0.5 },
  });
  if (ret2.error) {
    console.log(ret2.error);
    return;
  }

  // Insert picture with print properties
  const ret3 = f.AddPictureFromBytes('Sheet1', 'H2', {
    Extension: '.gif',
    File: fs.readFileSync('image.gif'),
    Format: {
      AltText: 'Picture 3',
      OffsetX: 15,
      OffsetY: 10,
      PrintObject: true,
      LockAspectRatio: false,
      Locked: false,
    },
  });
  if (ret3.error) {
    console.log(ret3.error);
    return;
  }

  const { buffer, error } = f.WriteToBuffer();
  if (error) {
    console.log(error);
    return;
  }
  fs.writeFile('Book1.xlsx', buffer, 'binary', (error) => {
    if (error) console.log(error);
  });
});