component.go

package golevel7

import (
	"fmt"
	"strings"
)

//Component is an HL7 component
type Component struct {
	SubComponents []SubComponent
	Value         []rune
}

func (c *Component) String() string {
	var str string
	for _, s := range c.SubComponents {
		str += "Component SubComponent: " + string(s.Value) + "\n"
	}
	return str
}

func (c *Component) parse(seps *Delimeters) error {
	r := strings.NewReader(string(c.Value))
	i := 0
	ii := 0
	for {
		ch, _, _ := r.ReadRune()
		ii++
		switch {
		case ch == eof || (ch == endMsg && seps.LFTermMsg):
			if ii > i {
				scmp := SubComponent{Value: c.Value[i : ii-1]}
				c.SubComponents = append(c.SubComponents, scmp)
			}
			return nil
		case ch == seps.SubComponent:
			scmp := SubComponent{Value: c.Value[i : ii-1]}
			c.SubComponents = append(c.SubComponents, scmp)
			i = ii
		case ch == seps.Escape:
			ii++
			r.ReadRune()
		}
	}
}

// SubComponent returns the subcomponent i
func (c *Component) SubComponent(i int) (*SubComponent, error) {
	if i > len(c.SubComponents) || i < 1 {
		return nil, fmt.Errorf("SubComponent out of range")
	}
	return &c.SubComponents[i-1], nil
}

func (c *Component) encode(seps *Delimeters) []rune {
	buf := []string{}
	for _, sc := range c.SubComponents {
		buf = append(buf, string(sc.Value))
	}
	return []rune(string(strings.Join(buf, string(seps.SubComponent))))
}

// Get returns the value specified by the Location
func (c *Component) Get(l *Location) (string, error) {
	if l.SubComp == -1 {
		return string(c.Value), nil
	}
	sc, err := c.SubComponent(l.SubComp)
	if err != nil {
		return "", err
	}
	return string(sc.Value), nil
}

// Set will insert a value into a message at Location
func (c *Component) Set(l *Location, val string, seps *Delimeters) error {
	subloc := l.SubComp
	if subloc < 0 {
		subloc = 0
	}
	if x := subloc - len(c.SubComponents) + 1; x > 0 {
		c.SubComponents = append(c.SubComponents, make([]SubComponent, x)...)
	}
	c.SubComponents[subloc].Value = []rune(val)
	c.Value = c.encode(seps)
	return nil
}