options.go

package filter

import (
	"errors"
)

// Option is the function that allows to set configuration options.
type Option func(p *Processor) error

// WithFieldNameTag allows to use the field names specified by the tag instead of the original struct names.
//
// Note that this is evaluated against the value before the first comma in the field definition.
// For example if a field is defined as: `json:my_field,omitempty`, the evaluated tag value is `my_field`.
//
// Returns an error if the tag is empty.
func WithFieldNameTag(tag string) Option {
	return func(p *Processor) error {
		if tag == "" {
			return errors.New("tag cannot be empty")
		}

		p.fields.fieldTag = tag

		return nil
	}
}

// WithQueryFilterKey sets the query parameter key that Processor.ParseURLQuery() looks for.
func WithQueryFilterKey(key string) Option {
	return func(p *Processor) error {
		if key == "" {
			return errors.New("query filter key cannot be empty")
		}

		p.urlQueryFilterKey = key

		return nil
	}
}

// WithMaxRules sets the maximum number of rules to pass to the Processor.Apply() function without errors.
// If this option is not set, it defaults to 3.
//
// Return an error if rulemax is less than 1.
func WithMaxRules(rulemax uint) Option {
	return func(p *Processor) error {
		if rulemax < 1 {
			return errors.New("max Rules must be at least 1")
		}

		p.maxRules = rulemax

		return nil
	}
}

// WithMaxResults sets the maximum length of the slice returned by Apply() and ApplySubset().
func WithMaxResults(resmax uint) Option {
	return func(p *Processor) error {
		if resmax < 1 {
			return errors.New("maxResults must be at least 1")
		}

		if resmax > MaxResults {
			return errors.New("maxResults must be less than MaxResults")
		}

		p.maxResults = resmax

		return nil
	}
}