html5 js 讀取csv檔案
阿新 • • 發佈:2019-02-05
//讀取檔案
function readParseFiles(callback) {
var data = [];
var files = [];
files.push(document.getElementById('file0').files[0], document.getElementById('file1').files[0],document.getElementById('file2').files[0],document.getElementById('file3').files[0]);
var index = 0;
~function () {
var reader = new FileReader();
reader.readAsText(files[index],'UTF-8');
index++;
var context = arguments.callee;
//讀取完檔案之後,執行下面這個回撥函式:
reader.onloadend = function (evt) {
if(evt.target.readyState == FileReader.DONE){
data.push(csv2array(reader.result.toString()));
if(index == files.length){
callback && callback(data);
}else {
context();
}
}
};
}();
};
//讀取檔案,判斷檔案的完整性
readParseFiles(function (data) {
console.log(data);
});
csv2Array
/**
* Convert data in CSV (comma separated value) format to a javascript array.
*
* Values are separated by a comma, or by a custom one character delimeter.
* Rows are separated by a new-line character.
*
* Leading and trailing spaces and tabs are ignored.
* Values may optionally be enclosed by double quotes.
* Values containing a special character (comma's, double-quotes, or new-lines)
* must be enclosed by double-quotes.
* Embedded double-quotes must be represented by a pair of consecutive
* double-quotes.
*
* Example usage:
* var csv = '"x", "y", "z"\n12.3, 2.3, 8.7\n4.5, 1.2, -5.6\n';
* var array = csv2array(csv);
*
* Author: Jos de Jong, 2010
*
* @param {string} data The data in CSV format.
* @param {string} delimeter [optional] a custom delimeter. Comma ',' by default
* The Delimeter must be a single character.
* @return {Array} array A two dimensional array containing the data
* @throw {String} error The method throws an error when there is an
* error in the provided data.
*/
function csv2array(data, delimeter) {
// Retrieve the delimeter
if (delimeter == undefined)
delimeter = ',';
if (delimeter && delimeter.length > 1)
delimeter = ',';
// initialize variables
var newline = '\n';
var eof = '';
var i = 0;
var c = data.charAt(i);
var row = 0;
var col = 0;
var array = new Array();
while (c != eof) {
// skip whitespaces
while (c == ' ' || c == '\t' || c == '\r') {
c = data.charAt(++i); // read next char
}
// get value
var value = "";
if (c == '\"') {
// value enclosed by double-quotes
c = data.charAt(++i);
do {
if (c != '\"') {
// read a regular character and go to the next character
value += c;
c = data.charAt(++i);
}
if (c == '\"') {
// check for escaped double-quote
var cnext = data.charAt(i+1);
if (cnext == '\"') {
// this is an escaped double-quote.
// Add a double-quote to the value, and move two characters ahead.
value += '\"';
i += 2;
c = data.charAt(i);
}
}
}
while (c != eof && c != '\"');
if (c == eof) {
throw "Unexpected end of data, double-quote expected";
}
c = data.charAt(++i);
}
else {
// value without quotes
while (c != eof && c != delimeter && c!= newline && c != ' ' && c != '\t' && c != '\r') {
value += c;
c = data.charAt(++i);
}
}
// add the value to the array
if (array.length <= row)
array.push(new Array());
array[row].push(value);
// skip whitespaces
while (c == ' ' || c == '\t' || c == '\r') {
c = data.charAt(++i);
}
// go to the next row or column
if (c == delimeter) {
// to the next column
col++;
}
else if (c == newline) {
// to the next row
col = 0;
row++;
}
else if (c != eof) {
// unexpected character
throw "Delimiter expected after character " + i;
}
// go to the next character
c = data.charAt(++i);
}
return array;
}