Release v0.10.0-beta

Changes in this PR are not backward compatible! Few things have changed. Hopefully, migration will not be painful for you. If you have any questions, please, let us know here or in our community Slack channel.

Changes:

• added message.Marshal(data) which sets values of message fields using values provided in data struct.
• added support of index tag for both message.Marshal() and message.Unmarshal(). Now you can name your fields as you want and used index tag to specify field index in the ISO8583 specification. Examples are here and here.
• removed iso8583.Unmarshal. Please, use message.Unmarshal instead.
• removed message.Data()
• deprecated message.SetData(data). Use message.Marshal() instead.
• deprecated field.SetData(data). Use field.Marshal(data) instead.
• changed current behavior of message.SetData(data). Before it could be used to get values into a struct after calling message.Unpack() like this:

data := &ISOMessage{}
mesage.SetData(data)
message.Unpack(rawMessage)

data.F1.Value //  if previous versions values were populated during unpacking, but now they are not

Now message.SetData(data) only sets field values. No way to get values back to the struct. In order to get values into struct you have to use message.Unmarshal(data) like this:

message.Unpack(rawMessage)
data := &ISOMessage{}
mesage.Unmarshall(data)

data.F1.Value //  now you can get the value

Migration Guide

Two main changes that you may need to do in your code:

1. Replace message.SetData(data) with message.Marshal(data). Latter, simply sets field values with values provided in the data struct. Without any side-effects.
2. Replce message.Data()(*YouMessageTypehere) with message.Unmarshal(data). It sets data` struct values with message field values. No side-effects.
3. If you used SetData() and call Unpack to get access to message field values, replace it with message.Unmarshal(data).

You have to change your code from this

type ISO87Data struct {
	F0 *field.String
	F2 *field.String
	F4 *field.String
}

message := NewMessage(spec)
data := &ISO87Data{}
err := message.SetData(data) // you "link" data internally
err = message.Unpack(rawMsg) // here values are populated into linked data struct. no more.

// now you access you
data.F0.Value
data.F2.Value
data.F4.Value

to this:

type ISO87Data struct {
	F0 *field.String
	F2 *field.String
	F4 *field.String
}

message := NewMessage(spec)
err := message.Unpack(rawMsg)

data := &ISO87Data{}
err = message.Unmarshal(data)

// now you access fields in data
data.F0.Value
data.F2.Value
data.F4.Value