I have tried unmarshalling various JSON and XML files with limited success. So I ended up writing a "lexer" along the lines of Rob Pike's lecture in Australia. I have had good success with it in a bunch of projects. I would be very interested to get some comments on what the community thinks of decoding XML, JSON and similarly encoded objects in this way. https://github.com/Saied74/lexer2
On Thursday, August 20, 2015 at 12:52:45 PM UTC-4, hajd...@gmail.com wrote: > > Is there any reason this *shouldn't* work? ( I realize it doesn't, just > curious since you can marshal an empty interface ). > > A contrived example: ( https://play.golang.org/p/s-Lh0qDwAP) > > type Person struct { > XMLName xml.Name `xml:"person"` > FirstName string `xml:"firstname"` > Parents interface{} `xml:"parent"` > } > > func main() { > type Parent struct { > FirstName string `xml:"name"` > LastName string `xml:"lastname"` > } > p := &Person{FirstName: "Steve"} > p.Parents = []Parent{Parent{"Jack","Doe"}, Parent{"Lynne","Doe"}} > data, err := xml.Marshal(p) > if err != nil { > fmt.Println(err) > } > fmt.Println("Marshalled:",string(data)) > p2 := &Person{} > p2.Parents = []Parent{} > err = xml.Unmarshal(data, p2) > if err != nil { > fmt.Println(err) > } > fmt.Println("Unmarshalled:", p2) > } > > > I get that by being an empty interface{}, there are no fields that are > exported for it to look at. Except that I'm assigning a concrete type to > the interface{}, so shouldn't Unmarshal be able to reflect that interface{} > and find the struct/tag names to Unmarshal the data? I'm assuming ( and > guessing I'm wrong ) that that's how Marshal does it? I think I'd probably > be less confused if Marshal wasn't working as well, but I don't get why > Marshal can deal with a interface{} and Unmarshal can't. > > The real use case I have being that the XML response I'm getting has some > static elements and then it has dynamic elements: > > <api> > <staticfield1>data</staticfield1> > <staticfield2>data</staticfield2> > <record> > <fieldname1>data</fieldname1> > <fieldname2>data</fieldname2> > </record> > <record> > .. > </record> > </api> > > I have the static fields in a struct, but fieldname's returned in the > record elements change, depending on which database table is being returned > by the api. I want to be able to create a record struct that matches what > I know the record will look like for each call, and then compose the whole > struct ( static fields + the dynamic fields ) that I'm unmarshalling into. > > The solution I have right now is to have a byte array that captures the > innerxml and then unmarshal that separately, but I felt like this would be > a cleaner solution. ( https://play.golang.org/p/z3BS6tjqgW ) > > If there isn't anyway to do this - is there anyway to grab a whole > <parent> record, with the <parent></parent> tags included? My byte > solution works, but the issue I run into is that my innerxml field just > ends up with <FirstName></FirstName><LastName></LastName>, with no > surrounding <parent> tags. So I have to add the parent tags back so that I > can unmarshal to a Parent struct, as you can see in the example. > > Any help appreciated! > > Steve > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/f4001087-f7b2-47db-aa62-00cf3a13ecd2%40googlegroups.com.
