【opencart3源码分析】货币类currency.php

<?php
namespace Cart;
/**
 * 货币类
 * @package Cart
 */
class Currency {
    // 货币种类
	private $currencies = array();

	public function __construct($registry) {
	    // 加载数据库类
		$this->db = $registry->get('db');
		// 加载语言类
		$this->language = $registry->get('language');
        // 查询货币
		$query = $this->db->query("SELECT * FROM " . DB_PREFIX . "currency");
        // 查询结果进行遍历
		foreach ($query->rows as $result) {
			$res = $this->currencies[$result['code']] = array(
				'currency_id'   => $result['currency_id'],
				'title'         => $result['title'],
				'symbol_left'   => $result['symbol_left'],
				'symbol_right'  => $result['symbol_right'],
				'decimal_place' => $result['decimal_place'],
				'value'         => $result['value']
			);
		}
	}

	// 格式化
	public function format($number, $currency, $value = '', $format = true) {
		$symbol_left = $this->currencies[$currency]['symbol_left'];
		$symbol_right = $this->currencies[$currency]['symbol_right'];
		$decimal_place = $this->currencies[$currency]['decimal_place'];

		if (!$value) {
			$value = $this->currencies[$currency]['value'];
		}

		$amount = $value ? (float)$number * $value : (float)$number;
		// 四舍五入
		$amount = round($amount, (int)$decimal_place);
		
		if (!$format) {
			return $amount;
		}

		$string = '';

		if ($symbol_left) {
			$string .= $symbol_left;
		}
        // 通过千位分组来格式化数字
		$string .= number_format($amount, (int)$decimal_place, $this->language->get('decimal_point'), $this->language->get('thousand_point'));

		if ($symbol_right) {
			$string .= $symbol_right;
		}

		return $string;
	}

	// 转换
	public function convert($value, $from, $to) {
		if (isset($this->currencies[$from])) {
			$from = $this->currencies[$from]['value'];
		} else {
			$from = 1;
		}

		if (isset($this->currencies[$to])) {
			$to = $this->currencies[$to]['value'];
		} else {
			$to = 1;
		}

		return $value * ($to / $from);
	}

	// 获取货币id
	public function getId($currency) {
		if (isset($this->currencies[$currency])) {
			return $this->currencies[$currency]['currency_id'];
		} else {
			return 0;
		}
	}

    // 货币符号在在金额左边显示
	public function getSymbolLeft($currency) {
		if (isset($this->currencies[$currency])) {
			return $this->currencies[$currency]['symbol_left'];
		} else {
			return '';
		}
	}

	// 货币符号在在金额右边显示
	public function getSymbolRight($currency) {
		if (isset($this->currencies[$currency])) {
			return $this->currencies[$currency]['symbol_right'];
		} else {
			return '';
		}
	}

	// 保留小数点后几位有效数字
	public function getDecimalPlace($currency) {
		if (isset($this->currencies[$currency])) {
			return $this->currencies[$currency]['decimal_place'];
		} else {
			return 0;
		}
	}

	public function getValue($currency) {
		if (isset($this->currencies[$currency])) {
			return $this->currencies[$currency]['value'];
		} else {
			return 0;
		}
	}
    // 判断是否存在
	public function has($currency) {
		return isset($this->currencies[$currency]);
	}
}