@rlemiengre/async-read-multiple-json

Version

1.0.0

Description

Asynchronously read the contents of one or more JSON files into a promise-wrapped array, in order to process the contents of the files only after they are all read and parsed correctly.

Usage

file1.json:

{
  "id": 1,
  "name": "name1",
  "content": [
    "item1",
    "item2"
  ],
  "visited": 11
}

file2.json:

{
  "id": 2,
  "name": "name2",
  "content": [
    "item1",
    "item2"
  ],
  "visited": 8
}

file3.json:

{
  "id": 3,
  "name": "name3",
  "content": [
    "item1",
    "item2"
  ],
  "visited": 0
}

index.js:

const asyncReadMultipleJSON = require(async-read-multiple-json);  

const jsonFiles = [ 
	'file1.json', 
	'file2.json', 
	'file3.json'
];   

asyncReadMultipleJSON(jsonFiles)
    .then(responses => { 
        for (let i=0; i<responses.length; i++) {
            console.log(responses[i]);
        }
    })
    .catch(err => {
        console.log(err.message);
    });

running the code:

>> node index.js

{
    "id": 1,
    "name": "name1",
    "content": [
      "item1",
      "item2"
    ],
    "visited": 11
}

{
    "id": 2,
    "name": "name2",
    "content": [
      "item1",
      "item2"
    ],
    "visited": 8
}

{
    "id": 3,
    "name": "name3",
    "content": [
      "item1",
      "item2"
    ],
    "visited": 0
}

Installation

Use the package manager npm to install @rlemiengre/async-read-multiple-json.

>> npm install --save @rlemiengre/async-read-multiple-json

API

syntax:

asyncReadMultipleJSON(fileList);

parameters:

fileList

An array of one or more JSON files to be read.

return value:

The function returns a promise (which resolves with an array of objects representing the contents of the provided JSON files).

Errors

When an exception happens during execution of the code, a custom error object will be thrown:

{
    code: <error-type>,
    file: <file-name>,
    message: <message>
}

Possible error-types (passed in the "code" property):

• "ERR_READ_ERROR": One of the files could not be read.

• "ERR_PARSE_ERROR": There was a problem parsing one of the provided files.

The "file" property contains the filename of the file where the error occurred.

The "message" property is a more verbose error message (also including the error type and filename).

License

MIT

Contributors

rlemiengre
https://github.com/rlemiengre