Created
August 24, 2015 01:55
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function makeCSVReader(records, opts) { | |
'use strict'; | |
function noop() {} | |
function createRecordConstructor(fields) { | |
var src = ''; | |
for (var i = 0; i < fields.length; i++) { | |
src += 'this[' + JSON.stringify(fields[i]) + '] = fields[' + i + '];\n'; | |
} | |
// EVAL, EVAL, EVAL | |
return new Function('fields', src); | |
} | |
var state = 1; | |
var fields = []; | |
var Record = null; | |
var field = []; | |
var onClose = opts.onClose || noop; | |
opts = opts || {}; | |
function terminateField() { | |
fields[fields.length] = field.join(''); | |
field = []; | |
} | |
function terminateRecordWithHeader() { | |
terminateField(); | |
if (Record == null) { | |
Record = createRecordConstructor(fields); | |
} else { | |
records.push(new Record(fields)); | |
} | |
fields = []; | |
} | |
function terminateRecordWithoutHeader() { | |
terminateField(); | |
records.push(fields); | |
fields = []; | |
} | |
var terminateRecord = opts.header ? | |
terminateRecordWithHeader : | |
terminateRecordWithoutHeader; | |
var COMMA = ','; | |
var CR = '\r'; | |
var LF = '\n'; | |
var DOUBLE_QUOTE = '"'; | |
var CTX_FIELD_START = 1; | |
var CTX_IN_FIELD = 2; | |
var CTX_IN_QUOTED_FIELD = 3; | |
var CTX_ON_QUOTE = 4; | |
var CTX_ON_CR = 5; | |
var EXPECTED_LINE_FEED = -1; | |
var EXPECTED_FIELD_TERMINATOR = -2; | |
return function readString(str) { | |
if (str == null) { | |
terminateRecord(); | |
onClose(); | |
return 0; | |
} | |
for (var i = 0; i < str.length; i++) { | |
var char = str[i]; | |
switch (state) { | |
case CTX_FIELD_START: | |
if (char === DOUBLE_QUOTE) { | |
state = CTX_IN_QUOTED_FIELD; | |
} else { | |
field = [char]; | |
state = CTX_IN_FIELD; | |
} | |
break; | |
case CTX_IN_FIELD: | |
if (char === CR) { | |
terminateRecord(); | |
state = CTX_ON_CR; | |
} else if (char === LF) { | |
terminateRecord(); | |
state = CTX_FIELD_START; | |
} else if (char === COMMA) { | |
terminateField(); | |
state = CTX_FIELD_START; | |
} else { | |
field[field.length] = char; | |
} | |
break; | |
case CTX_IN_QUOTED_FIELD: | |
if (char === DOUBLE_QUOTE) { | |
state = CTX_ON_QUOTE; | |
} else { | |
field[field.length] = char; | |
} | |
break; | |
case CTX_ON_QUOTE: | |
if (char === DOUBLE_QUOTE) { | |
field[field.length] = char; | |
state = CTX_IN_QUOTED_FIELD; | |
} else if (char === COMMA) { | |
terminateField(); | |
state = CTX_FIELD_START; | |
} else if (char === CR) { | |
terminateRecord(); | |
state = CTX_ON_CR; | |
} else { | |
return EXPECTED_FIELD_TERMINATOR; | |
} | |
break; | |
case CTX_ON_CR: | |
if (char !== LF) { | |
return EXPECTED_LINE_FEED; | |
} | |
state = CTX_FIELD_START; | |
break; | |
} | |
} | |
return str.length; | |
}; | |
} |
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