How to read file in angular 6

 You can use FileReader in javascript to achieve this as its a csv file

Add a file change event to store the file in a object as below,

<div class="Block">
<label id="lbl">Code </label>
<input type='file' (change)="fileChanged($event)">

</div>

The function should set the file to an object which is used later

file:any;
fileChanged(e) {
this.file = e.target.files[0];
}

When the submit button is clicked you can use the readAsText() method of FileReader in javascript to get the content as below,

uploadDocument(file) {
let fileReader = new FileReader();
fileReader.onload = (e) => {
console.log(fileReader.result);
}
fileReader.readAsText(this.file);
}

Noteonload event will be fired after the content is read so your logic should be inside the onLoad function.