Hi Brian, Thanks for the reply (and for shepherding the project).
Regarding Json. I’ll take a look at the Java code. I’ve also used Newtonsoft for things like this previously. JsonTextReader/JsonTextWriter look like they would map easily to the Avro Encode/Decoder interfaces. The banner on the Json.NET <http://json.net/> documentation says "JsonTextWriter Class Represents a writer that provides a fast, non-cached, forward-only way of generating JSON data.”, which seems like what we need. https://www.newtonsoft.com/json/help/html/T_Newtonsoft_Json_JsonTextWriter.htm <https://www.newtonsoft.com/json/help/html/T_Newtonsoft_Json_JsonTextWriter.htm> Regarding Newtonsoft version. Maybe 10.0.3? It is 2 years old and 2 major versions back. It is also by far the most popular download on nuget. For what I’m trying to do (better error reporting while parsing) I just need the JToken to to have the Path property. Regarding Roslyn. This is a detailed intro/tutorial https://medium.com/@CPP_Coder/introduction-to-roslyn-and-its-use-in-program-development-bce2043fc45d <https://medium.com/@CPP_Coder/introduction-to-roslyn-and-its-use-in-program-development-bce2043fc45d>. It is the compiler framework that’s being used for code analysis tools, cross compilers etc. For code->schema I’m thinking to do the following: - open the solution - use the syntax walker https://joshvarty.com/2014/07/26/learn-roslyn-now-part-4-csharpsyntaxwalker/ <https://joshvarty.com/2014/07/26/learn-roslyn-now-part-4-csharpsyntaxwalker/> to parse the required class, then generate a schema (or possibly a protocol for an entire namespace). I haven’t thought a lot about the code generation side. But what I’m hoping is that we can parse the C#, as with schema generation, and then generate updates to the code by modifying the syntax tree. This will have the effect of editing the C# and preserving any edits, unmapped properties, and comments the developer has made. https://msdn.microsoft.com/en-us/magazine/mt808499.aspx <https://msdn.microsoft.com/en-us/magazine/mt808499.aspx>. As I’m typing this I think the reverse for the schema would be good too - load C# and schema and then edit the schema tree to sync any changes rather than just regenerating it every time. > On Jul 11, 2019, at 5:05 PM, Brian Lachniet <blachn...@gmail.com> wrote: > > Hi Patrick! > > I'm sorry I haven't gotten back to the Reflect review yet. I'm hoping to > get back on that this weekend. > > That sounds like a good list of additions. I'm particularly interested in > having support for JSON encoding/decoding in C#. I bet we could get a long > ways simply porting the JsonEncoder > <https://github.com/apache/avro/blob/master/lang/java/avro/src/main/java/org/apache/avro/io/JsonEncoder.java> > from the Java bindings. > > I agree that we need to bump the Newtonsoft.Json verison. That just came up > in another issue recently. What version of Newtonsoft.Json do you think we > should upgrade to? I'm a little wary of bumping all the way to the latest, > as that would force everyone using Avro to also go to the latest version. > Maybe that's not a bad thing, I'm not sure. > > I'm not familiar with Roslyn-based code generation. I'll do some Googling > on that (if you've got some good articles or starting points to share, I'd > appreciate that). Codegen currently uses the System.CodeDom API. Would > Roslyn-based code generation be a replacement for that, or am I > misunderstanding something? > > Thank you for your patience so far, Patrick. I'm looking forward to these > new features too! > > On Thu, Jul 11, 2019 at 6:14 PM Patrick Farry <patrick.s.fa...@gmail.com> > wrote: > >> Hi Brian, >> >> Not meaning to hassle you (well maybe a little). I’ve got a few other >> enhancements we'd like to do as well as the Reflect code, and was hoping >> not to have to maintain a bunch of branches. >> >> Here are the planned changes: >> - update newtonsoft.json and add the json path whenever the schema parser >> reports an error - we have a number of large schemas and debugging them is >> proving difficult >> - Roslyn based schema generator from C# class >> - Reflect option added to codegen (possibly updating codegen to use Roslyn) >> - Serialize to json >> >> Thanks. >> >>> On May 2, 2019, at 6:22 PM, Brian Lachniet <blachn...@gmail.com> wrote: >>> >>> Hey Patrick, >>> >>> This sounds very useful! I'd love to see this introduced to the C# >> library. >>> >>> On Thu, May 2, 2019 at 5:47 PM Ivan Greene <igre...@fanthreesixty.com> >>> wrote: >>> >>>> Patrick, >>>> >>>> This sounds as though it would be the C# equivalent of Java's >> ReflectData, >>>> which has been part of the Avro API for several years now, so it’s >> likely >>>> there would be interest. Your best bet is to open a Jira describing the >>>> planned feature and open a pull request on Github to start the >> discussion. >>>> The contributing page on the wiki is a bit out of date and still >> recommends >>>> submitting patches on Jira but I believe that Github is now the official >>>> repository. >>>> >>>>> On May 1, 2019, at 4:31 PM, Patrick Farry <patrick.s.fa...@gmail.com> >>>> wrote: >>>>> >>>>> Hi All, >>>>> >>>>> I have written code that implements Avro serialization for POCO classes >>>> - i.e. classes that are not generated by Avro codegen and do not >> implement >>>> ISpecificRecord. The idea was to make it work as much like JSON.net as >>>> possible. >>>>> >>>>> The serializer inherits from SpecificDefaultWriter and the deserializer >>>> from SpecificDefaultReader. >>>>> >>>>> Avro fields are mapped to C# properties either by matching the field >>>> name and property name or by using an attribute to specify the field >>>> sequence number. >>>>> >>>>> Is this something that would be of interest to the Avro project? My >>>> company has approved committing the code and I’d be available and happy >> to >>>> maintain this code and work on other parts of the C# implementation. >>>>> >>>>> Regards. >>>>> >>>>> >>>> >>>> >>> >>> -- >>> >>> [image: 51b630b05e01a6d5134ccfd520f547c4.png] >>> >>> Brian Lachniet >>> >>> Software Engineer >>> >>> E: blachn...@gmail.com | blachniet.com <http://www.blachniet.com> >>> >>> <https://twitter.com/blachniet> <http://www.linkedin.com/in/blachniet> >> >> > > -- > > [image: 51b630b05e01a6d5134ccfd520f547c4.png] > > Brian Lachniet > > Software Engineer > > E: blachn...@gmail.com | blachniet.com <http://www.blachniet.com> > > <https://twitter.com/blachniet> <http://www.linkedin.com/in/blachniet>
