CSV to JSON in Typescript
I am trying to create a JSON file from the data received from a CSV file uploaded using a file uploader input.
I have found lots of posts doing this in Javascript but they just aren't quite working for me in Typescript.
The error I get when running the below code is csv.Split is not a function, does anyone have any ideas how I can alter my code to work.
Let me know if you need more information and Thanks in advance.
component.ts
public testFile() {
var file = (<HTMLInputElement>document.getElementById('fileInput')).files[0];
var jsonFile = this.csvJSON(file);
// Set Http POST options
let headers = new Headers({ 'Content-Type': 'application/json' });
let options = new RequestOptions({ headers: headers });
// Call Api with test connection data
this.http
.post('/api/TestConnection/TestConnection', jsonFile, options)
.subscribe(data => {
// alert request ok
alert('ok');
}, error => {
// Log error
console.log(error.json());
});
}
public csvJSON(csv) {
var lines = csv.split("n");
var result = [];
var headers = lines[0].split(",");
for (var i = 1; i < lines.length; i++) {
var obj = {};
var currentline = lines[i].split(",");
for (var j = 0; j < headers.length; j++) {
obj[headers[j]] = currentline[j];
}
result.push(obj);
}
//return result; //JavaScript object
return JSON.stringify(result); //JSON
}
You are passing File to csvJSON method instead of file's text. You can use FileReader to read its content. Here's an example
const convertFile = () => {
const input = document.getElementById('fileInput');
const reader = new FileReader();
reader.onload = () => {
let text = reader.result;
console.log('CSV: ', text.substring(0, 100) + '...');
//convert text to json here
//var json = this.csvJSON(text);
};
reader.readAsText(input.files[0]);
};<input type='file' onchange='convertFile(event)' id='fileInput'>HTML
<input type="file" accept=".csv (change)="csv2Array($event)">
Typescript
csv2Array(fileInput: any){
//read file from input
this.fileReaded = fileInput.target.files[0];
let reader: FileReader = new FileReader();
reader.readAsText(this.fileReaded);
reader.onload = (e) => {
let csv: string = reader.result;
let allTextLines = csv.split(/r|n|r/);
let headers = allTextLines[0].split(',');
let lines = [];
for (let i = 0; i < allTextLines.length; i++) {
// split content based on comma
let data = allTextLines[i].split(',');
if (data.length === headers.length) {
let tarr = [];
for (let j = 0; j < headers.length; j++) {
tarr.push(data[j]);
}
// log each row to see output
console.log(tarr);
lines.push(tarr);
}
}
// all rows in the csv file
console.log(">>>>>>>>>>>>>>>>>", lines);
}
}