Excel Help

Helper + Middleware for exporting excel files based on sheetjs

Installation

npm install excel-help

Include

Include into js app using common js.

const excelHelp = require("excel-help")

Usage

Excel Help can be used in two ways.

1. As an express js middleware - To quickly export some data comig from an api as Excel File.
2. As a standalone helper - To aid in creating worksheets and workspaces

Middleware

Usage

app.use(excelHelp.middleware);

The middleware accepts data in following format to quickly export a json array) or an array of arrays or both and provides a function res.xlsx to export it as a file / stream.

res.xlsx("export.xlsx",  [
  {
    "type": "json",
     "data": [{
       "foo":"bar",
       "bar":"foo",
       "abc":"def"
     },
     {
        "foo":"xyz", 
        "bar":"lak",
        "abc":"mkx"
     }]
},
{
  "type": "columns",
  "data": [
    ["yqmxc", "kqyui", "zhasi", "kljhda"],
    ["yqmxl", "kqyuiads", "zhasida", null, new Date()]
   ]
}
], config?config:{})

It accepts an array of objects of folklowing format:

{
	"type" :  //"json" or "columns",
	"data": //the data //Array of objects //Array of arrays,
	"options" // options object (Not Mandatory)
}

options

• If type is "columns" options
• If type is "json" We can use the in built sheetjs options along with these options

  • headerMap - headerMap is an object which can be used to transform the column names. By default the key of the data object is considered as the header.

    {headerMap: {"foo":"FOO","bar":"BAR"}}
    

    • excludeHeaders - excludeHeaders is an array of headers that one wants to exclude from the export.

config

config may contain the workbook configuration as defined config

Standalone

Usage

const ExcelHelp = require("excel-help");
let excelHelpWb = new ExcelHelp().addSheet(
[
  {
    "type": "json",
     "data": [{
       "foo":"bar",
       "bar":"foo",
       "abc":"def"
     },
     {
        "foo":"xyz", 
        "bar":"lak",
        "abc":"mkx"
     }]
},
{
  "type": "columns",
  "data": [
    ["yqmxc", "kqyui", "zhasi", "kljhda"],
    ["yqmxl", "kqyuiads", "zhasida", null, new Date()]
   ]
}
],
"sheet1",     //Name of the sheet (Not Mandatory)

config?config:{}    // config object (NotMandatory)

)
.addSheet(
[
 {
    "type": "json",
      "data": [
        {
          "foo":"xyz",
          "bar":"lak",
          "abc":"mkx"
        }
      ]
   }
 ],

"sheet2",   //Name of the sheet (Not Mandatory)

config?config:{}   // config object (NotMandatory)

)
.build() 

The method addSheet can be chained any no of times to add muliple sheets to the workbook. addSheet contains a config option which might be used to do operations on the worksheet like changing the width or merging columns.

Changing Column Widths

{"!cols": [ { wch: 10 } ]}

Other examples can be found on sheetjs

The build functions returns the workbook object . The user can then proced to modify the workbook as he needs or write the workbook

Example

new ExcelHelp().XLSX.writeFile(excelHelpWb, filename, write_opts)