I'm new to d3.js so I know this might seem as a silly question to some so please bear with me. I'm trying to parse a csv file which a user uploads and print it's output in the console. I'm able to parse the CSV file when I provide the absolute path of the CSV file but when I try doing the same with file upload functionality I'm not getting any output in the console..
Working Javascript Code..
var dataset = [];
d3.csv("sample.csv", function(data) {
dataset = data.map(function(d) { return [ d["Title"], d["Category"], d["ASIN/ISBN"], d["Item Total"] ]; });
console.log(dataset[0]);
console.log(dataset.length);
});
Console Output...
["Men's Brooks Ghost 8 Running Shoe Black/High Risk Red/Silver Size 11.5 M US", "Shoes", "B00QH1KYV6", "$120.00 "]
8
New HTML code..
<input type="file" id="csvfile" name="uploadCSV"/>
<br/>
<button onclick="howdy()">submit</button>
Modified Javascript Code(not working)..
var myfile = $("#csvfile").prop('files')[0];
var reader = new FileReader();
reader.onload = function(e) {
var text = reader.result;
}
reader.readAsDataURL(myfile);
var dataset = [];
d3.csv(reader.result , function(data) {
dataset = data.map(function(d) { return [ d["Title"], d["Category"], d["ASIN/ISBN"], d["Item Total"] ]; });
console.log(dataset[0]);
console.log(dataset.length);
})
Since there was no official documentation on how to handle user uploaded CSV file I can't figure out where I'm going wrong..Is there a way I can use HTML5 file reader?? Please help..
You are close but you don't need to and can't call d3.csv
on a reader.result. d3.csv
makes an async AJAX call to retrieve a CSV file from a server. You already have the file contents and just want to parse, so use d3.csv.parse.
Full working example:
<!DOCTYPE html>
<html>
<head>
<script data-require="[email protected]" data-semver="3.5.3" src="//cdnjs.cloudflare.com/ajax/libs/d3/3.5.3/d3.js"></script>
</head>
<body>
<input type="file" onchange="loadFile()" />
<script>
var reader = new FileReader();
function loadFile() {
var file = document.querySelector('input[type=file]').files[0];
reader.addEventListener("load", parseFile, false);
if (file) {
reader.readAsText(file);
}
}
function parseFile(){
var doesColumnExist = false;
var data = d3.csv.parse(reader.result, function(d){
doesColumnExist = d.hasOwnProperty("someColumn");
return d;
});
console.log(doesColumnExist);
}
</script>
</body>
</html>
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