Alasql: Error while using with TypeScript: Error: "Please include the xlsx.js library"

[eluleci]

I am working on a project which is created with create-react-app which has TypeScript version. You can see from here: https://github.com/Microsoft/TypeScript-React-Starter

The library is added to package json as:
"alasql": "^0.4.5"

The library is imported like:
import * as alasql from 'alasql';

When it is executed like:

const opts = [{ sheetid: fileName, header: true }];
alasql(`SELECT * INTO XLSX("${fileName}.xlsx",?) FROM ?`, [opts, [list]]);

the app crashes and the error message is:
Error: Please include the xlsx.js library

[mathiasrw]

Does it work if you select into a csv file? "SELECT * INTO CSV"?

The solution is to include the xlsx.js library (as stated in the error message)

Have a look at https://github.com/SheetJS/js-xlsx

[mathiasrw]

Any news on this?

[eluleci]

I tried "SELECT * INTO CSV", it doesn't crash but the generated file is not a valid file.

I checked the code and saw that the XLSX is taken from XLSX = utils.global.XLSX || null; where the global is defined like

utils.global = (function() {
    try {
        return Function('return this')();
    } catch (e) {
        //If Content Security Policy
        var global = self || window || global;

        if (global) {
            return global;
        } else {
            throw new Error('Unable to locate global object');
        }
    }
})();

So I imported xlsx library and put the XLSX into window like (window as any).XLSX = xlsx; but it is still not working. However I can reach to window.XLSX from browser console.

I also tried to add the xlsx into the HTML with script tag <script lang="javascript" src="/xlsx.min.js"/> but the typescript project doesn't compile when there is a javascript file referenced in a script tag.

How should I include the xlsx.js library for alasql.js to see it?

[eluleci]

I also tried to see what is in utils.global by logging it like console.log((alasql as any).utils.global) and it seems it is referenced to Window and it has XLSX in it.

[eluleci]

It seems like the issue is getXLSX function. utils.isBrowserify is true when importing the package from TypeScript file like import * as alasql from 'alasql';, so it falls into the first condition and never assigns the XLSX. BTW the Window.XLSX exists at that moment. I have no idea why the first condition is empty. You must be knowing the reason better.

var getXLSX = function() {
    var XLSX = null;
    /* If require() shuold be supported else take from global scope */
    if (utils.isNode || utils.isBrowserify || utils.isMeteorServer) {
        /*not-for-browser/*
        XLSX = require('xlsx') || null;
        //*/
    } else {
        XLSX = utils.global.XLSX || null;
    }

    if (null === XLSX) {
        throw new Error('Please include the xlsx.js library');
    }

    return XLSX;
};

So if the function would be like this it would do the same thing for both conditions. (Since the first condition is empty anyway) and it fixes the TypeScript issue.

var getXLSX = function() {
    var XLSX = (utils.global && utils.global.XLSX) ? utils.global.XLSX : null;

    if (null === XLSX) {
        throw new Error('Please include the xlsx.js library');
    }
    return XLSX;
};

Would it be OK to change the function like this?

[mathiasrw]

Thank you so much for your time to look into this.

The /*not-for-browser/* is used to have code that compiles both to a node version and for a browser version. Now, the problem is that typescript is handeling the default - the node version. But actually it should use the browser version. What part of the code is default would not be a large change. Ill look into it next weekend.

[eluleci]

Awesome. Thanks.

[mathiasrw]

It was a bit more cryptic than expected.

I added a new function: alasql.setXLSX(...) so you can load XLSX manually and parse it into alasql instead of it trying to load XLSX.

Please try this and let me know if it fixed this.

• Make sure you are using the latest code from this repo by replacing "alasql": "^0.4.5" with "alaswl": "github:agershun/alasql" in package.json
• Do a npm install xlsx
• Include XLSX with a import { XLSX } from 'xlsx'
• Before using alasql do a alasql.setXLSX(XLSX);
• See if it works.

[eluleci]

I tried it and I got error while calling alasql.setXLSX(XLSX); function because the setXLSX function doesn't exist in alasql.js.

Also I have to import the alasql like const alasql = require('alaswl'); instead of import * as alasql from 'alaswl';. Otherwise the compilation fails with error ... alasql.d.ts is not a module.