CsvToArray.php

<?php
/**
 * @copyright HomeCu 05/2019
 *
 * A wrapper class for str_getcsv() to parse a CSV file into an array.
 * Leaves off escape param, can be added if needed . . . .
 * ***ASSUMES*** (and really should be) first row of CSV are field names. It is shifted
 * off the stack and used as field names for associative array as below.
 *
 * Usage:
 * $obj = new CsvToArray([path to dummie data CSV file], [optional string delimiter], [optional string enclosure]);
 * $obj->ParseData();
 *
 * "Enclosure" is better known as "qualifier" as in quote-qualified fields.
 *
 * Returns array [
 *  'errors' => [],
 *  'data'  => [
 *    [int row index] => [
 *      [string field] => [mixed value],
 *      ....
 *    ]
 *  ];
 *
 */
class CsvToArray
{
  /** @var string|null for str_getcsv(), defaults to ',' */
  protected $delimiter = null;

  /** @var string|null for str_getcsv(), also known as qualifier as in "quote qualified fields" */
  protected $enclosure = null;

  /** @var array data returned as documented above */
  protected $response = [];

  /** @var int keeps track of line seek internally */
  protected $line_num = 0;

  /** @var SplFileObject, object created WITH the injected CSV path */
  protected $SplFileObj = null;

  /**
   * @var array on construction create the return associative array. On subsequent lines,
   * we use array_combine() to return an associative array containing the CSV data.
   */
  protected $array_template = [];

  /**
   * Constructor, initialize response and set path to CSV. Set delimiter and
   * enclosure first, setArrayTemplate() uses them.
   * @param string $csv_path
   * @param string $delimiter
   * @param string $enclosure
   * @return void
   */
  public function __construct($csv_path = '', $delimiter = ',', $enclosure = null) {

    $this
      ->InitResponseArray()
      ->Set('delimiter', $delimiter)
      ->Set('enclosure', $enclosure)
      ->SetFileObject($csv_path)
      ->SetArrayTemplate();
  }

  /**
   * Get the associative array of $this->array_template mapped to CSV data rows.
   * @return array|false
   */
  public function ParseData() {

    $this->line_num++;
    $this->SplFileObj->seek($this->line_num);

    if ($this->SplFileObj->eof())  {
      $this->CloseFile();
      return false;
    }

    return $this
      ->CombineCsvArray($this->SplFileObj->current())
      ->ReturnResponse();
  }


  /**
   * Check that the SplFileObject is still an object (not null)
   * @return bool
   */
  public function IsLinesToProcess() {

    return ! is_null($this->SplFileObj);
  }

  /**
   * Initialize the response
   * @return $this
   */
  protected function InitResponseArray() {

    $this->response = [
      'errors'  => [],
      'data'    => []
    ];

    return $this;
  }

  /**
   * A typical setter, sets internal properties (delimiter, enclosure)
   * Usually setters are public, don't think we'll need it externally
   * @param string $prop property identifier
   * @param string $value property to set
   * @return $this
   */
  protected function Set($prop, $value) {

    if (! $value || empty($value)) {
      return $this;
  }

    $this->{$prop} = $value;

    return $this;
  }

  /**
   * Instantiate the native SplFileObject. We could call it directly, setting
   * it as a property makes it a little more visible.
   * @param string $file
   * @return $this
   */
  protected function SetFileObject($file) {

    $this->SplFileObj = new SplFileObject($file);

    return $this;
  }

  /**
   * Initialize $this->array_template from the first row in the CSV.
   * @return $this
   */
  protected function SetArrayTemplate() {

    $this->SplFileObj->seek(0);
    $this->array_template = str_getcsv($this->SplFileObj->current(), $this->delimiter, $this->enclosure);

    return $this;
  }

  /**
   * Leverage str_getcsv()to parse the CSV file.
   * @param string $line
   * @return $this
   */
  protected function CombineCsvArray($line = '') {

    if ($this->IsErrors()) {
      return $this;
    }

    $data = str_getcsv($line, $this->delimiter, $this->enclosure);

    if (! $this->DataMatchesTemplateLength($data)) {

      $this->response['errors'][] = "
        The data length is incorrect, please check the CSV file.
        The columns in the header MUST match the columns in the data rows." . PHP_EOL;
      return $this;
    }

    $this->response['data'] = $this->CreateAssociativeArrays($data);

    return $this;
  }

  /**
   * Validate we can do array_combine
   * @param array $data
   * @return bool
   */
  protected function DataMatchesTemplateLength($data) {

    return count($data) == count($this->array_template);
  }

  /**
   * Map the data to the first row of fields so we have an associative array.
   * @param array $data
   * @return array
   */
  protected function CreateAssociativeArrays($data) {

    return array_combine($this->array_template, $data);
  }

  /**
   * Close filehandles by setting SplFileObject to null. Public so if the
   * requested number of records is less than file length we can close it.
   * @return $this
   */
  public function CloseFile() {

    if ($this->SplFileObj) {
      $this->SplFileObj = null;
    }

    return $this;
  }

  /**
   * Return a response, this approach allows chaining of methods above it.
   * @return array
   */
  protected function ReturnResponse() {

    return $this->response;
  }

  /**
   * Got errors?
   * @return bool
   */
  protected function IsErrors() {

    return count($this->response['errors']) > 0;
  }

}