views_handler_field_math.inc

<?php


/**
 * @file
 * Definition of views_handler_field_math.
 */

/**
 * Render a mathematical expression as a numeric value.
 *
 * Definition terms:
 * - float: If true this field contains a decimal value. If unset this field
 *   will be assumed to be integer.
 *
 * @ingroup views_field_handlers
 */
class views_handler_field_math extends views_handler_field_numeric {
    
    /**
     * {@inheritdoc}
     */
    public function option_definition() {
        $options = parent::option_definition();
        $options['expression'] = array(
            'default' => '',
        );
        return $options;
    }
    
    /**
     * {@inheritdoc}
     */
    public function options_form(&$form, &$form_state) {
        $form['expression'] = array(
            '#type' => 'textarea',
            '#title' => t('Expression'),
            '#description' => t("Enter mathematical expressions such as 2 + 2 or sqrt(5). You may assign variables and create mathematical functions and evaluate them. Use the ; to separate these. For example: f(x) = x + 2; f(2). The result of the previous row's mathematical expression can be accessed by using the [expression] token itself."),
            '#default_value' => $this->options['expression'],
        );
        // Create a place for the help.
        $form['expression_help'] = array();
        parent::options_form($form, $form_state);
        // Then move the existing help.
        $form['expression_help'] = $form['alter']['help'];
        unset($form['expression_help']['#dependency']);
        unset($form['alter']['help']);
    }
    
    /**
     * {@inheritdoc}
     */
    public function render($values) {
        ctools_include('math-expr');
        $tokens = array_map('floatval', $this->get_render_tokens(array()));
        $value = strtr($this->options['expression'], $tokens);
        $expressions = explode(';', $value);
        $math = new ctools_math_expr();
        foreach ($expressions as $expression) {
            if ($expression !== '') {
                $value = $math->evaluate($expression);
            }
        }
        // The rest is directly from views_handler_field_numeric but because it
        // does not allow the value to be passed in, it is copied.
        if (!empty($this->options['set_precision'])) {
            $value = number_format($value, $this->options['precision'], $this->options['decimal'], $this->options['separator']);
        }
        else {
            $remainder = abs($value) - intval(abs($value));
            $value = $value > 0 ? floor((double) $value) : ceil((double) $value);
            $value = number_format($value, 0, '', $this->options['separator']);
            if ($remainder) {
                // The substr may not be locale safe.
                $value .= $this->options['decimal'] . substr($remainder, 2);
            }
        }
        // Check to see if hiding should happen before adding prefix and suffix.
        if ($this->options['hide_empty'] && empty($value) && ($value !== 0 || $this->options['empty_zero'])) {
            return '';
        }
        // Should we format as a plural.
        if (!empty($this->options['format_plural']) && ($value != 0 || !$this->options['empty_zero'])) {
            $value = format_plural($value, $this->options['format_plural_singular'], $this->options['format_plural_plural']);
        }
        return $this->sanitize_value($this->options['prefix'] . $value . $this->options['suffix']);
    }
    
    /**
     * {@inheritdoc}
     */
    public function query() {
    }

}