read-and-write v1.1.7
Getting Started
Start by importing the constructor function
const ReadAndWrite = require("read-and-write").ReadAndWrite;
Next create a new instance of the constructor function with the path to the file that you want to read from and write to
const fileReader = new ReadAndWrite("./users.txt");
Reading From A File
Synchronously
The following line reads all records from the file
let users = fileReader.readAllRecordsSync();
It should return an array of objects, each object representing one record
Example:
[
{
username: 'berrybloxinator',
firstName: 'Brady',
lastName: 'Liechty',
email: 'berrybloxinator@gmail.com',
age: '20',
userId: '03a13ff9-9bfe-483f-8cc5-fa16caf1898b',
timeCreated: '1/28/2020, 2:33:33 PM'
},
{
username: 'skateboardnerd',
firstName: 'John',
lastName: 'Hill',
email: 'skateboard4life@gmail.com',
age: '25',
userId: '3ef6972e-6c71-4fd2-82df-da4c2dc9baf5',
timeCreated: '1/28/2020, 2:34:18 PM'
}
]
Asynchronously
To use this function asynchronously you have the option pass a callback that will be called when all the files contents have been read
The readAllRecords function will call your callback with the file contents formatted as an array of objects just like with the readAllRecordsSync function
let users = [];
fileReader.readAllRecords(fileContents => {
users = fileContents;
});
Appending Records
Synchronously
To append records pass in an array of objects
let users = [];
const d = new Date();
const tempUsers = [
{
username: "Destiny",
firstName: "Steven",
lastName: "Bonnell",
email: "destiny@gmail.com",
age: 32,
userId: uuid.v4(),
timeCreated: d.toLocaleString()
},
{
username: "xXhardcore_gamerXx",
firstName: "Doug",
lastName: "Smith",
email: "league4life@gmail.com",
age: 29,
userId: uuid.v4(),
timeCreated: d.toLocaleString()
}
];
fileReader.appendRecordsSync(tempUsers);
Append records does not return anything so in this case I have to manually add the appended users to my array
users.push(...tempUsers);
Appending records will not overwrite the file, only add to the end of it.
Asynchronously
If you do this function asynchronously you have the option of passing in a callback that will do whatever you want it to whenever the function has appended the user(s)
This callback is not called with any parameters
let users = [];
const d = new Date();
const tempUsers = [
{
username: "Destiny",
firstName: "Steven",
lastName: "Bonnell",
email: "destiny@gmail.com",
age: 32,
userId: uuid.v4(),
timeCreated: d.toLocaleString()
},
{
username: "xXhardcore_gamerXx",
firstName: "Doug",
lastName: "Smith",
email: "league4life@gmail.com",
age: 29,
userId: uuid.v4(),
timeCreated: d.toLocaleString()
}
];
fileReader.appendRecords(tempUsers, () => {
console.log("user successfully appended to file");
});
users.push(...tempUsers);
Writing Records
Synchronously
Writing records is done almost the exact same way except for the fact that the file is overwritten
let users = [];
const d = new Date();
const tempUsers = [
{
username: "Destiny",
firstName: "Steven",
lastName: "Bonnell",
email: "destiny@gmail.com",
age: 32,
userId: uuid.v4(),
timeCreated: d.toLocaleString()
},
{
username: "xXhardcore_gamerXx",
firstName: "Doug",
lastName: "Smith",
email: "league4life@gmail.com",
age: 29,
userId: uuid.v4(),
timeCreated: d.toLocaleString()
}
];
fileReader.writeRecordsSync(tempUsers);
users = tempUsers;
Asynchronously
Just like the asynchronous version of appendUsers you can pass in a callback that will do whatever you want when the users are written to the file
This callback is not called with any parameters
let users = [];
const d = new Date();
const tempUsers = [
{
username: "Destiny",
firstName: "Steven",
lastName: "Bonnell",
email: "destiny@gmail.com",
age: 32,
userId: uuid.v4(),
timeCreated: d.toLocaleString()
},
{
username: "xXhardcore_gamerXx",
firstName: "Doug",
lastName: "Smith",
email: "league4life@gmail.com",
age: 29,
userId: uuid.v4(),
timeCreated: d.toLocaleString()
}
];
fileReader.writeRecords(tempUsers, () => {
console.log("Users successfully written to file");
});
users = tempUsers;
Deleting Records
Synchronously
To delete a record you have to pass in an id
An id is an object that is used to identify the record that you want to be deleted
let users = [];
users = fileReader.deleteRecordSync({
key: "name",
value: "Brady"
});
Pretty self explanatory
This will find the record with the key and value that you pass in
It will remove it from the file and return an array with all of of the records except the one that was deleted
Asynchronously
Keep in mind that for deleteRecord your callback will be called with an updated array of your records
let users = [];
fileReader.deleteRecord({
key: "name",
value: "Brady"
}, refactoredUsers => {
users = refactoredUsers;
});
Editing Records
Synchronously
This is the most complicated function in this package
Just like the delete records function, the first parameter is an id to determine which record to edit
The second parameter is an array of id's to tell the function which parts of the record you want to change
The second parameter is where you specify the key and then specify what value you want the keys value to change to
let users = [];
users = fileReader.editRecordSync({
key: "userId",
value: 3ef6972e-6c71-4fd2-82df-da4c2dc9baf5
}, [
{
key: "username",
value: "AnthonyPadilla"
}, {
key: "email",
value: "anthony.padilla@gmail.com"
}
]);
After running this the record with the userId of 3ef6972e-6c71-4fd2-82df-da4c2dc9baf5 would change from
{
username: "A_Padilla",
firstName: "Anthony",
lastName: "Padilla",
email: "a_padilla@gmail.com",
age: 29,
userId: 3ef6972e-6c71-4fd2-82df-da4c2dc9baf5,
timeCreated: 1/28/2020, 2:34:18 PM
}
to
{
username: "AnthonyPadilla",
firstName: "Anthony",
lastName: "Padilla",
email: "anthony.padilla@gmail.com",
age: 29,
userId: 3ef6972e-6c71-4fd2-82df-da4c2dc9baf5,
timeCreated: 1/28/2020, 2:34:18 PM
}
The editRecordSync function will return an array with all of the records including the edited record
Asynchronously
Your callback will again be called with an updated array of your records
let users = [];
fileReader.editRecord({
key: "userId",
value: 3ef6972e-6c71-4fd2-82df-da4c2dc9baf5
}, [
{
key: "username",
value: "AnthonyPadilla"
}, {
key: "email",
value: "anthony.padilla@gmail.com"
}
], refactoredUsers => {
users = refactoredUsers;
});
Notes
The records that you write to a file can have any amount of key value pairs and you can have whatever keys and values you wish
The callback is optional for every asynchronous version of all functions
Synchronous functions will always end with Sync and asynchronous functions will not
readAllRecordsSync (synchronous)
readAllRecords (asynchronous)