Csv Laravel Package

Getting Started

Start by installing the package via Composer:

composer require league/csv:^9.0

Import Reader or Writer classes and use named constructors — avoid new — to instantiate:

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

$reader = Reader::createFromPath('/path/to/file.csv', 'r');
$writer = Writer::createFromPath('php://output', 'w');

Key first use case: read a CSV with headers → map rows to objects or arrays:

$records = $reader->setOffset(1)->fetchAssoc(0); // key by first column
// or
$records = $reader->setOffset(1)->fetchAll();

Check the official docs at csv.thephpleague.com for deep examples and API reference.

Implementation Patterns

• Stream-first workflow: Use createFromPath, createFromUrl, or createFromString to wrap PHP streams without loading full CSV into memory.
• Pipeline processing: Chain filters and modifiers:

  $reader
      ->setFilterCallback(fn(array $row) => count($row) === 5)
      ->addSortBy(2, SORT_STRING, SORT_DESC)
      ->setOffset(10)
      ->setLimit(50)
      ->fetchAll();
  

• Export workflows: Map arrays to CSV with insertOne()/insertAll(), add BOM for Excel compatibility ($writer->setOutputBOM(Writer::BOM_UTF8)), and force downloads via output().
• Transcoding pipelines: Use stream_filter_register() and appendStreamFilter() (7.0+), or the provided FilterTranscode in examples for charset conversion (e.g., UTF-8 → UTF-16 LE for Excel on macOS).
• Framework-agnostic integration: Use with Laravel’s Storage::disk('local')->readStream() or Symfony’s StreamedResponse seamlessly by passing streams.

Gotchas and Tips

• PHP 8.4+: Explicitly set the escape character ($writer->setEscape('\\') or '') to avoid deprecation notices.
• Line endings: Legacy Mac CSVs (carriage return only) require auto_detect_line_endings on (but note: deprecated in PHP 8.1+, removed in 9.0). Use createFromPath with 'r' mode to avoid issues.
• BOM handling: Detect input BOM with $reader->getInputBOM(); always output BOM explicitly for Excel compatibility (BOM_UTF8, BOM_UTF16_LE).
• Delimiter detection: Use detectDelimiterList() (not detectDelimiter())—it never throws; returns array of candidates, so handle ambiguity gracefully.
• Streaming caution: Writer opened in append mode ('a') should be rewound manually if you need to re-read. Prefer 'w' or 'w+' for writing and use newReader()/newWriter() to cross-operate.
• Memory safety: Prefer fetchOne(), fetchAssoc(), fetchColumn(), or generators over fetchAll() for large files.
• Upgrading: Renamed methods like setEncoding → setEncodingFrom (v6), getReader()/getWriter() → newReader()/newWriter(). Always check CHANGELOG when upgrading major versions.