README.md

Importing data from xlsx as simple as possible

Getting Started:

1. Install the package:

npm i xlsx-import --save

2. Write a config:

    const config = {
        books: {
            type: 'list',
            worksheet: 'Favourites',
            columns: [
                {
                    index: 1, // column index (1,2,3....n); `1` for column `A`
                    key: 'Id', // output item's field
                    mapper: (v: string) => Number.parseInt(v) // nullable, for transformating values
                },
                {index: 2, key: 'Title'}, // column `B`
                {index: 5, key: 'Author'}, // column `E`
            ],
            rowOffset: 1, // offset header row
        },
        owner: {
            worksheet: 'About list owner',
            type: 'object',
            fields: [
                {row: 2, col: 1, key: 'FirstName'}, // `A2`
                {row: 2, col: 2, key: 'SecondName'}, // `B2`
                {row: 3, col: 1, key: 'Age', mapper: Number.parseInt}, // `A3`
            ]
        },
    };

3. Use mappers (optional):

Mapper is a function that transforms values. You can use built-in mappers or write your own

    import { upperCaseMapper, isEmpty, isFilled } from 'xlsx-import/lib/mappers';

    const config = {
        // ...
        owner: {
            worksheet: 'About list owner',
            type: 'object',
            fields:[
                {row: 2, col: 1, key: 'FirstName'},
                {row: 2, col: 2, key: 'SecondName', mapper: upperCaseMapper},
                {row: 3, col: 1, key: 'Age', mapper: Number.parseInt},
                // three fields based on one cell but with different mapper
                {row: 2, col: 3, key: 'EmployedIn'},
                {row: 2, col: 3, key: 'IsUnemployed', mapper: isEmpty},
                {row: 2, col: 3, key: 'IsEmployed', mapper: isFilled},
            ]
        },
    };

4. Types:

interface Book {
    Id: number;
    Title: string;
    Author: string;
}

interface Person {
    FirstName: string;
    SecondName: string;
    Age: number;

    EmployedIn: string;
    IsUnemployed: boolean;
    IsEmployed: boolean;
}

5. Import data:

    const factory = new ImporterFactory();

    //...

    const importer = await factory.from(filePath);
    const books = importer.getAllItems<Book>(config.books); // it returns `Book[]`
    const author = importer.getAllItems<Person>(config.owner);

Samples

Sample integration with xlsx-import are placed in ./samples directory. Currently available:

• NodeJS sample of importing an invoice - it is pure JS example which runs on nodejs.
• NodeJS + TS sample of importing an invoice - it is Typescript example that can be transpiled down to pure JS or run directly with ts-node.
• ExpressJS sample - it is a small service created with ExpressJS can parse xlsx files with concrete structure

The configuration:

worksheet

It is a string, indicates which worksheet should be used for data source.

types

Enum ImportType	Raw values	Description
Default: List, aliases: ListVertical, Vertical	list, list-vertical, vertical	Used to import list of objects from worksheet reading from top to down (row by row). Each field has to defined column index (A is 1, B is 2 ... etc.).
Object, aliases: Single, Singleton	object, single, singletion	Used to import single object from worksheet. Each field has to has defined row&col index.

What in case of performing incorrect type parameter value?

Here is a implementation of fallback mechanism to attempting to parse data as ListVertical, which is the common type used in this library.
In that case console.warn will be written.

fields or columns

This is type related configuration, for more information please study examples above, there are a full configuration used.

Mappers

Exported Name	Description
upperCaseMapper	Transforms string to upper case
lowerCaseMapper	Transforms string to lower case
jsonMapper	Transforms a json string to a TJsonResponse or to null if parsing was not possible
isEmpty	Examines if input is empty
isFilled	Examines if input is not empty
splitMapper	Transforms string into array of items

splitMapper

Configurable and immutable splitMapper with possibility to use specific itemMapper<TReturnType>(mapper) or separator(string).

• .separator(';'): SplitMapper - set separator
• .itemMapper(itemMapper): SplitMapper - set mapper for items,

Setting separator or item mapper do not change origin mapper but create new one. As a item mapper may use also another splitMapper like below:

// Building a mapper
const sentenceSplitter = splitMapper.separator('. ');
const wordSplitter = splitMapper.separator(' ');
const wordsInSentencesMapper = sentenceSplitter.itemMapper<string[]>(wordSplitter);

// Standalone usage:
const input = 'Lorem ipsum dolor sit amet. consectetur adipiscing elit. Nullam placerat massa nec efficir. ';
           
const result = wordsInSentencesMapper(input);   
// [
//     ['Lorem', 'ipsum', 'dolor', 'sit', 'amet'],
//     ['consectetur', 'adipiscing', 'elit'],
//     ['Nullam', 'placerat', 'massa', 'nec', 'efficir'],
//     ['']
// ]


// In a config:
// {row: 3, col: 1, key: 'words', mapper: wordsInSentencesMapper},

See also

• XLSX-renderer - makes generating excel files as simple as possible - it is enough one line to generate pretty customizable spreadsheet file.
• ts-package-structure - the robust structure which I use to creating packages.
• MIT LICENSE

Supported Node version:

8	9	10	11	12	13	14
❌	❌	✅	✅	✅	✅	✅

Node v8 and v9 compatibly was drop after upgrade ExcelJS to version 4+ and it is able to turn on by downgrading xlsx-import to version 2.2.1 or if needed really important by requesting me directly.