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.. | ||
.gitignore | ||
Makefile | ||
README.md | ||
_cors.js | ||
_logit.js | ||
_request.js | ||
drash.ts | ||
express.js | ||
hapi.js | ||
koa.js | ||
koasub.js | ||
nest.sh | ||
nodejs.js | ||
sheetjs.controller.ts | ||
sheetjs.csv | ||
sheetjs.module.ts | ||
worker.js |
NodeJS Server Deployments
This library is 100% pure JS. This is great for compatibility but tends to lock up long-running processes. In the web browser, Web Workers are used to offload work from the main browser thread. In NodeJS, there are other strategies. This demo shows a few different strategies applied to different server frameworks.
NOTE: these examples merely demonstrate the core concepts and do not include appropriate error checking or other production-level features.
Express Setup
The following commands are required in order to test the Express demo:
npm install express printj express-formidable https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz
node express.js
Koa Setup
The following commands are required in order to test the Koa demo:
npm install koa printj formidable https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz
node koa.js
Hapi Setup
Note: Hapi demo as written only works with Hapi version 16 and below.
The following commands are required in order to test the Hapi demo:
npm install hapi@16.x printj tiny-worker https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz
node hapi.js
Node Buffer
The read
and write
functions can handle Buffer
data with type:"buffer"
.
For example, the request
library returns data in a buffer:
var XLSX = require('xlsx'), request = require('request');
request(url, {encoding: null}, function(err, res, data) {
if(err || res.statusCode !== 200) return;
/* data is a node Buffer that can be passed to XLSX.read */
var workbook = XLSX.read(data, {type:'buffer'});
/* DO SOMETHING WITH workbook HERE */
});
The readFile
/ writeFile
functions wrap fs.{read,write}FileSync
:
/* equivalent to `var wb = XLSX.readFile("sheetjs.xlsx");` */
var buf = fs.readFileSync("sheetjs.xlsx");
var wb = XLSX.read(buf, {type:'buffer'});
Responding to Form Uploads
Using formidable
, files uploaded to forms are stored to temporary files that
can be read with readFile
:
/* within the server callback function(request, response) { */
var form = new formidable.IncomingForm();
form.parse(req, function(err, fields, files) {
var f = files[Object.keys(files)[0]];
var workbook = XLSX.readFile(f.path);
/* DO SOMETHING WITH workbook HERE */
});
The node.js
demo shows a plain HTTP server that accepts file uploads and
converts data to requested output format.
Example servers
Each example server is expected to hold an array-of-arrays in memory. They are expected to handle:
POST /
accepts an encodedfile
and updates the internal storageGET /?t=<type>
returns the internal storage in the specified typePOST /?f=<name>
reads the local file and updates the internal storageGET /?f=<name>
writes the file to the specified name
Testing with cURL is straightforward:
# upload sheetjs.csv and update data
curl -X POST -F "data=@sheetjs.csv" http://localhost:7262/
# download data in SYLK format
curl -X GET http://localhost:7262/?t=slk
# read sheetjs.csv from the server directory
curl -X POST http://localhost:7262/?f=sheetjs.csv
# write sheetjs.xlsb in the XLSB format
curl -X GET http://localhost:7262/?f=sheetjs.xlsb
Main-process logic with express
The most straightforward approach is to handle the data directly in HTTP event
handlers. The buffer
type for XLSX.read
and XLSX.write
work with http
module and with express directly. The following snippet generates a workbook
based on an array of arrays and sends it to the client:
function send_aoa_to_client(req, res, data, bookType) {
/* generate workbook */
var ws = XLSX.utils.aoa_to_sheet(data);
var wb = XLSX.utils.book_new();
XLSX.utils.book_append_sheet(wb, ws, "SheetJS");
/* generate buffer */
var buf = XLSX.write(wb, {type:'buffer', bookType:bookType || "xlsx"});
/* send to client */
res.status(200).send(buf);
}
fork with koa
child_process.fork
provides a light-weight and customizable way to offload
work from the main server process. This demo passes commands to a custom child
process and the child passes back buffers of data.
The main server script is koa.js
and the worker script is koasub.js
. State
is maintained in the worker script.
tiny-worker with hapi
tiny-worker
provides a Web Worker-like interface. Binary strings and simple
objects are readily passed across the Worker divide.
The main server script is hapi.js
and the worker script is worker.js
. State
is maintained in the server script.
Note: due to an issue with hapi payload parsing, the route POST /file
is used
to handle the case of reading from file, so the cURL test is:
# upload sheetjs.csv and update data
curl -X POST -F "data=@sheetjs.csv" http://localhost:7262/
# download data in SYLK format
curl -X GET http://localhost:7262/?t=slk
# read sheetjs.csv from the server directory
curl -X POST http://localhost:7262/file?f=sheetjs.csv
# write sheetjs.xlsb in the XLSB format
curl -X GET http://localhost:7262/?f=sheetjs.xlsb
NestJS
NestJS is a Node.js framework for server-side web applications.
This demo uses SheetJS to parse a spreadsheet via a POST API endpoint. The file
arrives to the endpoint as body form-data
, accessible using the file
key.
After parsing the file, CSV contents of the first worksheet will be returned.
Body parsing uses multer
.
Before running the demo, the NestJS CLI tool must be installed. The instruction is described in the NestJS "First Steps":
npm i -g @nestjs/cli
make nest
The demo can be tested using the /sheetjs/upload-xlsx-file
endpoint:
curl -X POST -F "file=@test.xlsx" http://localhost:3000/sheetjs/upload-xlsx-file
The included nest.sh
script creates and configures the project.
This demo creates a module and a controller. The controller handles the actual
requests (creating the endpoint) while the module is used to configure multer
.
Deno
Drash
is a Deno framework for Deno's HTTP server.
The drash.ts
demo responds to POST requests and responds with HTML previews.
https://s2c.deno.dev is a live deployment of the service.