// The complex example allows a user to write the config file multiple times, possibly applying edits incrementally.
// When the user is ready for the application to apply the config changes, modify the 'version' value and the
// new config is applied.
func complex(parser *args.ArgParser) args.WatchCancelFunc {
// Get our current config
appConf := parser.GetOpts()
configFile := appConf.String("config-file")
// Watch the file every time.Second and call func(err error){} when the file is modified
cancelWatch, err := args.WatchFile(configFile, time.Second, func(err error) {
if err != nil {
fmt.Printf("Watch Error %s\n", err.Error())
return
}
// load the file from disk
content, err := args.LoadFile(configFile)
if err != nil {
fmt.Printf("Failed to load config - %s\n", err.Error())
}
// Parse the file contents
newConfig, err := parser.ParseINI(content)
if err != nil {
fmt.Printf("Failed to update config - %s\n", err.Error())
return
}
// Only "Apply" the newConfig when the version changes
if appConf.Int("version") != newConfig.Int("version") {
// Apply the newConfig values to the parser rules
appConf, err = parser.Apply(newConfig)
if err != nil {
fmt.Printf("Probably a type cast error - %s\n", err.Error())
return
}
}
})
if err != nil {
log.Fatal(fmt.Sprintf("Failed to watch '%s' - %s", configFile, err.Error()))
}
return cancelWatch
}
Expect(opt.String("value")).To(Equal(""))
Expect(opt.Int("version")).To(Equal(0))
iniFile, err = ioutil.TempFile("/tmp", "args-test")
if err != nil {
Fail(err.Error())
}
defer os.Remove(iniFile.Name())
// Write version 1 of the ini file
if err := saveFile(iniFile.Name(), iniVersion1); err != nil {
Fail(err.Error())
}
// Load the INI file
content, err := args.LoadFile(iniFile.Name())
if err != nil {
Fail(err.Error())
}
// Parse the ini file
opt, err = parser.FromINI(content)
Expect(err).To(BeNil())
Expect(log.GetEntry()).To(Equal(""))
Expect(opt.String("value")).To(Equal("my-value"))
Expect(opt.Int("version")).To(Equal(1))
done := make(chan struct{})
cancelWatch, err := args.WatchFile(iniFile.Name(), time.Second, func(err error) {
parser.FromINIFile(iniFile.Name())
// Tell the test to continue, Change event was handled
close(done)