xlstream

Memory-efficiently turns XLSX file into a transform stream with all its benefits.

• Stream is pausable.
• Emits all default events (data, end, etc.)
• Returns header, raw and formatted row data, as well as totalSheetSize and processedSheetSize (in bytes) in just one data event.
• Maintains desirable behavior of merged cells.
• Supports files created by OpenXML.
• Supports standard, Excel and custom number formats.

Installation

npm install xlstream

Example

source.xlsx contents:

| A | B | | ----- | --- | | hello | 123 |

Where 123 is a 123.123 number formatted to be rounded to integer.

Script:

const { getXlsxStream } = require("xlstream");

(async () => {
  const stream = await getXlsxStream({
    filePath: "./source.xlsx",
    sheet: 0,
  });
  stream.on("data", (x) => console.log(x));
})();

Result:

{
    "raw": {
        "obj": { "A": "hello", "B": 123.123 },
        "arr": [ "hello", 123.123 ]
    },
    "formatted": {
        "obj": { "A": "hello", "B": 123 },
        "arr": [ "hello", 123 ]
    },
    "header": [],
    "totalSheetSize": 1110,
    "processedSheetSize": 1110
}

getXlsxStream

Returns transform stream of the sheet.

Options

| option | type | description | | --------------- | --------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | filePath | string | Path to the XLSX file | | sheet | string or number | If string is passed, finds sheet by it's name. If number, finds sheet by it's index. | | withHeader | boolean or number | If true, column names will be taken from the first sheet row. If duplicated header name is found, column name will be prepended with column letter to maintain uniqueness. 0-based row location can be passed to this option if header is not located on the first row. | | ignoreEmpty | boolean | If true, empty rows won't be emitted. | | fillMergedCells | boolean | If true, merged cells will have the same value (by default, only the first cell of merged cells is filled with value). Warning! Enabling this feature may increase streaming time because file must be processed to detect merged cells before actual stream. | | numberFormat | standard or excel or object | By default standard format is used. Excel implementation of number formatting differs from standard (can be read here) so excel option can be used to match this difference. If custom formatting is needed, a dictionary object can be passed to this option. | | encoding | string | Sets file encoding. |

getXlsxStreams

Async generator which yields transform streams of the sheets.

Options

| Option | Type | Description | | -------- | ---------------------- | ------------------------------------------- | | filePath | string | Path to the XLSX file | | sheets | array of sheet objects | Options of sheet object can be found below. | | encoding | string | Sets file encoding. |

Sheet object

| option | type | description | | --------------- | --------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | id | string or number | If string is passed, finds sheet by it's name. If number, finds sheet by it's index. | | withHeader | boolean | If true, column names will be taken from the first sheet row. If duplicated header name is found, column name will be prepended with column letter to maintain uniqueness. 0-based row location can be passed to this option if header is not located on the first row. | | ignoreEmpty | boolean | If true, empty rows won't be emitted. | | fillMergedCells | boolean | If true, merged cells will have the same value (by default, only the first cell of merged cells is filled with value). Warning! Enabling this feature may increase streaming time because file must be processed to detect merged cells before actual stream. | | numberFormat | standard or excel or object | By default standard format is used. Excel implementation of number formatting differs from standard (can be read here) so excel option can be used to match this difference. If custom formatting is needed, a dictionary object can be passed to this option. |

getWorksheets

Returns array of sheets with name and hidden info.

Options

| Option | Type | Description | | -------- | -------- | ----------------------- | | filePath | string | Path to the XLSX file |

Building

You can build js source by using npm run build command.

Testing

Tests can be run by using npm test command.