I want to read the file uploaded by users on the client side and then do processing on them, instead of doing it on server-side. Is it possible read fil开发者_高级运维es and do manipulation using javascript on client side. Is it possible to use VBScript for this
I've done some very simple xlsx parsing in the browser. See https://gist.github.com/3375836. Try it out at http://jsfiddle.net/fAKGA/2. Copied here for convenience:
/*
Relies on jQuery, underscore.js, Async.js (https://github.com/caolan/async), and zip.js (http://gildas-lormeau.github.com/zip.js).
Tested only in Chrome on OS X.
Call xlsxParser.parse(file) where file is an instance of File. For example (untested):
document.ondrop = function(e) {
var file = e.dataTransfer.files[0];
excelParser.parse(file).then(function(data) {
console.log(data);
}, function(err) {
console.log('error', err);
});
}
*/
xlsxParser = (function() {
function extractFiles(file) {
var deferred = $.Deferred();
zip.createReader(new zip.BlobReader(file), function(reader) {
reader.getEntries(function(entries) {
async.reduce(entries, {}, function(memo, entry, done) {
var files = ['xl/worksheets/sheet1.xml', 'xl/sharedStrings.xml'];
if (files.indexOf(entry.filename) == -1) return done(null, memo);
entry.getData(new zip.TextWriter(), function(data) {
memo[entry.filename.split('/').pop()] = data;
done(null, memo);
});
}, function(err, files) {
if (err) deferred.reject(err);
else deferred.resolve(files);
});
});
}, function(error) { deferred.reject(error); });
return deferred.promise();
}
function extractData(files) {
var sheet = $(files['sheet1.xml']),
strings = $(files['sharedStrings.xml']),
data = [];
var colToInt = function(col) {
var letters = ["", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"];
var col = $.trim(col).split('');
var n = 0;
for (var i = 0; i < col.length; i++) {
n *= 26;
n += letters.indexOf(col[i]);
}
return n;
};
var Cell = function(cell) {
cell = cell.split(/([0-9]+)/);
this.row = parseInt(cell[1]);
this.column = colToInt(cell[0]);
};
var d = sheet.find('dimension').attr('ref').split(':');
d = _.map(d, function(v) { return new Cell(v); });
var cols = d[1].column - d[0].column + 1,
rows = d[1].row - d[0].row + 1;
_(rows).times(function() {
var _row = [];
_(cols).times(function() { _row.push(''); });
data.push(_row);
});
sheet.find('sheetData row c').each(function(i, c) {
var $cell = $(c),
cell = new Cell($cell.attr('r')),
type = $cell.attr('t'),
value = $cell.find('v').text();
if (type == 's') value = strings.find('si t').eq(parseInt(value)).text();
data[cell.row - d[0].row][cell.column - d[0].column] = value;
});
return data;
}
return {
parse: function(file) {
return extractFiles(file).pipe(function(files) {
return extractData(files);
});
}
}
})();
The browser should make it impossible to access local files (and we all should be happy about that). But the user could install a .HTA that can do short of everything on the local/client computer.
In short, No. The is no way for javascript to access the filesystem, this would be a major security threat/attack vector.
Absolutely not. For security purposes, this must be done server side. I can't think of single reason you wouldn't want to do it that way anyway.
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