layout: default title: Instantiation using named constructors redirect_from: /instantiation/

Instantiation

The library is composed of two main classes:

• League\Csv\Reader to read data from a CSV
• League\Csv\Writer to write new data into a CSV

Both classes extend the League\Csv\AbstractCsv class and as such share methods for instantiation.

Csv and Macintosh

If your CSV document was created or is read on a Macintosh computer, add the following lines before using the library to help PHP detect line ending in Mac OS X.

if (!ini_get("auto_detect_line_endings")) {
    ini_set("auto_detect_line_endings", '1');
}

//the rest of the code continues here...

Instantiating a new CSV object

Because CSVs come in different forms we used named constructors to offer several ways to instantiate the library objects.

AbstractCsv::createFromPath

This named constructor will create a new object à la fopen.

public static AbstractCsv::createFromPath(
    mixed $path,
    string $open_mode = 'r+'
): AbstractCsv

• The $path parameter can be:
  • a SplFileInfo object, the string path will be fetch from the object public methods.
  • an object implementing the __toString method the path will be the object string representation.
  • a string.

The resulting string and $open_mode parameters are used to lazy load internally a SplFileObject object.

use League\Csv\Reader;
use League\Csv\Writer;

$reader = Reader::createFromPath('/path/to/your/csv/file.csv', 'r');
//the $reader object will use the 'r+' open mode as no `open_mode` parameter was supplied.
$writer = Writer::createFromPath(new SplFileObject('/path/to/your/csv/file.csv', 'a+'), 'w');
//the $writer object open mode will be 'w'!!

AbstractCsv::createFromFileObject

Instantiate a new Csv object from a SplFileObject.

public static AbstractCsv::createFromFileObject(SplFileObject $obj): AbstractCsv

This method accepts only one single parameter, a SplFileObject object.

use League\Csv\Reader;
use League\Csv\Writer;

$reader = Reader::createFromFileObject(new SplFileObject('/path/to/your/csv/file.csv'));
$writer = Writer::createFromFileObject(new SplTempFileObject());

AbstractCsv::createFromString

This named constructor will create a new object from a given string.

public static AbstractCsv::createFromString(mixed $str): AbstractCsv

This method accepts only one single parameter, an object implementing the __toString method or a string.

use League\Csv\Reader;
use League\Csv\Writer;

$reader = Reader::createFromString('john,doe,john.doe@example.com');
$writer = Writer::createFromString('john,doe,john.doe@example.com');

AbstractCsv::createFromStream

This named constructor will create a new object from a stream resource.

public static AbstractCsv::createFromStream(resource $stream): AbstractCsv

This method accepts only one single parameter, a resource stream. The resource stream MUST be seekable otherwise a InvalidArgumentException will be thrown.

use League\Csv\Reader;
use League\Csv\Writer;

$reader = Reader::createFromStream(fopen('/path/to/the/file.csv', 'r+'));
$writer = Writer::createFromStream(fopen('php://temp', 'r+'));

Switching from one class to the other

At any given time you can switch or create a new League\Csv\Writer or a new League\Csv\Reader from the current object. To do so, you can use the following methods.

• the newReader to create a new League\Csv\Reader object;
• the newWriter to create a new League\Csv\Writer object;

Both methods accept an optional $open_mode parameter.

public AbstractCsv::newReader(string $open_mode = 'r+'): Reader
public AbstractCsv::newWriter(string $open_mode = 'r+'): Writer

• When not explicitly set, the $open_mode default value is r+ for both methods.
• If the initial object $open_mode parameter was not taken into account any new CSV object created with these methods won't take into account the given $open_mode.

$reader = $writer->newReader('r+');
$newWriter = $reader->newWriter('a');
$anotherWriter = $newWriter->newWriter('r+');