In this article I will explain with an example, how to read, parse and display a CSV file (Comma separated Text file) selected in FileUpload control (HTML File Input) on client side using JavaScript, jQuery and HTML5.
HTML5 allows developers to access the file contents and details using JavaScript and jQuery and hence in browsers that support HTML5 one can easily read the file contents.
Read, Parse and display CSV (Text) file using JavaScript and HTML5
The HTML Markup consists of a FileUpload control (HTML File Input) and a HTML Button.
The CSV file is selected in FileUpload control (HTML File Input) and Upload button is clicked and the Upload JavaScript function is called.
Inside the function, first a check is performed to verify whether the file is a valid CSV or a text file. Then a check is performed to make sure whether the browser supports HTML5 File API.
Once the above checks are cleared then the contents of the CSV file are read as text string and then the string is split into parts using comma and new line characters and finally is displayed as an HTML Table.
<script type="text/javascript">
function Upload() {
var fileUpload = document.getElementById("fileUpload");
var regex = /^([a-zA-Z0-9\s_\\.\-:])+(.csv|.txt)$/;
if (regex.test(fileUpload.value.toLowerCase())) {
if (typeof (FileReader) != "undefined") {
var reader = new FileReader();
reader.onload = function (e) {
var table = document.createElement("table");
var rows = e.target.result.split("\n");
for (var i = 0; i < rows.length; i++) {
var row = table.insertRow(-1);
var cells = rows[i].split(",");
for (var j = 0; j < cells.length; j++) {
var cell = row.insertCell(-1);
cell.innerHTML = cells[j];
}
}
var dvCSV = document.getElementById("dvCSV");
dvCSV.innerHTML = "";
dvCSV.appendChild(table);
}
reader.readAsText(fileUpload.files[0]);
} else {
alert("This browser does not support HTML5.");
}
} else {
alert("Please upload a valid CSV file.");
}
}
</script>
<input type="file" id="fileUpload" />
<input type="button" id="upload" value="Upload" onclick="Upload()" />
<hr />
<div id="dvCSV">
</div>
Read, Parse and display CSV (Text) file using jQuery and HTML5
The HTML Markup consists of a FileUpload control (HTML File Input) and a HTML Button.
The CSV file is selected in FileUpload control (HTML File Input) and Upload button is clicked. The Upload button is wired with a jQuery OnClick event handler.
Inside the event handler, first a check is performed to verify whether the file is a valid CSV or a text file. Then a check is performed to make sure whether the browser supports HTML5 File API.
Once the above checks are cleared then the contents of the CSV file are read as text string and then the string is split into parts using comma and new line characters and finally is displayed as an HTML Table.
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript">
$(function () {
$("#upload").bind("click", function () {
var regex = /^([a-zA-Z0-9\s_\\.\-:])+(.csv|.txt)$/;
if (regex.test($("#fileUpload").val().toLowerCase())) {
if (typeof (FileReader) != "undefined") {
var reader = new FileReader();
reader.onload = function (e) {
var table = $("<table />");
var rows = e.target.result.split("\n");
for (var i = 0; i < rows.length; i++) {
var row = $("<tr />");
var cells = rows[i].split(",");
for (var j = 0; j < cells.length; j++) {
var cell = $("<td />");
cell.html(cells[j]);
row.append(cell);
}
table.append(row);
}
$("#dvCSV").html('');
$("#dvCSV").append(table);
}
reader.readAsText($("#fileUpload")[0].files[0]);
} else {
alert("This browser does not support HTML5.");
}
} else {
alert("Please upload a valid CSV file.");
}
});
});
</script>
<input type="file" id="fileUpload" />
<input type="button" id="upload" value="Upload" />
<hr />
<div id="dvCSV">
</div>
Screenshots
Contents of the CSV file placed on user’s folder
The CSV file being displayed in browser as HTML Table
Browser Compatibility
The above code has been tested in the following browsers only in versions that support HTML5.
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