inklabs/rangedb

package aggregategenerator
 
import (
    "fmt"
    "io"
    "text/template"
    "time"
    "unicode"
)
 
var NowFunc = time.Now
 
// Write generates the boilerplate aggregate Go code required for the cqrs package.
func Write(out io.Writer, pkg, aggregateName string, commands, events []string) error {
    if len(commands)+len(events) < 1 {
        return fmt.Errorf("no commands or events found")
    }
 
    return fileTemplate.Execute(out, templateData{
        Timestamp:     NowFunc(),
        Commands:      commands,
        Events:        events,
        AggregateName: aggregateName,
        Package:       pkg,
    })
}
 
type templateData struct {
    Timestamp     time.Time
    Commands      []string
    Events        []string
    AggregateName string
    Package       string
}
 
func lcFirst(str string) string {
    for i, v := range str {
        return string(unicode.ToLower(v)) + str[i+1:]
    }
    return ""
}
 
var funcMap = template.FuncMap{
    "LcFirst": lcFirst,
}
 
var fileTemplate = template.Must(template.New("").Funcs(funcMap).Parse(`// Code generated by go generate; DO NOT EDIT.
// This file was generated at
// {{ .Timestamp }}
package {{ $.Package }}
 
import (
    "github.com/inklabs/rangedb"
    "github.com/inklabs/rangedb/pkg/cqrs"
)
 
func (a *{{ .AggregateName }}) Load(recordIterator rangedb.RecordIterator) {
    for recordIterator.Next() {
{{- if .Events }}
        if recordIterator.Err() == nil {
            if event, ok := recordIterator.Record().Data.(rangedb.Event); ok {
                a.apply(event)
            }
        }
{{- end }}
    }
}
 
{{- if .Events }}
 
func (a *{{ .AggregateName }}) apply(event rangedb.Event) {
    switch e := event.(type) {
{{- range .Events }}
 
    case {{ . }}:
        a.{{ . | LcFirst }}(e)
 
    case *{{ . }}:
        a.{{ . | LcFirst }}(*e)
{{- end }}
 
    }
}
{{- end }}
 
func (a *{{ .AggregateName }}) Handle(command cqrs.Command) []rangedb.Event {
{{- if .Commands }}
    switch c := command.(type) {
{{- range .Commands }}
 
    case {{ . }}:
        a.{{ . | LcFirst }}(c)
 
    case *{{ . }}:
        a.{{ . | LcFirst }}(*c)
{{- end }}
 
    }
{{ end }}
    defer a.resetPendingEvents()
    return a.pendingEvents
}
 
func (a *{{ .AggregateName }}) resetPendingEvents() {
    a.pendingEvents = nil
}
 
func (a *{{ .AggregateName }}) CommandTypes() []string {
    return []string{
{{- range .Commands }}
        {{ . }}{}.CommandType(),
{{- end }}
    }
}
 
func (a *{{ .AggregateName }}) raise(events ...rangedb.Event) {
    a.pendingEvents = append(a.pendingEvents, events...)
}
`))