Why the need for a Root about flatbuffers HOT 10 CLOSED

Any table can be a root in a buffer. The root type is mostly for use by JSON, which doesn't specify any types, so we need to know where to start. The generated GetRoot functions are merely convenience.

from flatbuffers.

Ok, thanks. But in Java,

1. If i have a ByteBuffer of a non root table how do read that using FlatBuffersBuilder. The only way I know is to use the __init() function, is there another way?
2. Is there a way to know the type of the table from the binary data?
3. How to use the addXXXType function, in your JavaTest.java you used: Monster.addTestType(fbb, (byte)1); how do you get the type of a table, in this case 1 which it is hard-coded ?

from flatbuffers.

1. a commit was pushed yesterday that adds GetRootAs functions for all tables, not just the root_type.

2. generally no. this is a strongly types system, meaning you need to know the kind of buffer you're dealing with. If you want to use this in a context where you want to have multiple different root types, you have these options:
   a) make your root type a table that contains a union of all possible sub-roots.
   b) prefix flatbuffers with your own file header
   c) use flatbuffer's built-in file indentification feature, which hasn't been ported to Java yet. I'll get to that.

3. That's a bug, the 1 should actually read: Any.Monster. I'll fix that.

from flatbuffers.

Thanks

1. But i think the name should be just "get" or "init" instead of getRootAs

from flatbuffers.

getRootAs is a bit more descriptive and less likely to clash with other identifiers. I think I'll keep it for now.

To further my response to your issue #2, the built-in file_identifier functionality is now also available in Java. See the Schema docs, Java docs, and Java code.

from flatbuffers.

So... How do I access non root_type buffers, can't find anything like Get*** in c++ generated files and the same problem in go lang.
generated code has huge differencies between languages and it's really hard to work with

from flatbuffers.

Tried both latest master and latest release versions

from flatbuffers.

In C++ there is the GetRoot templated function that works with any table type.
Go appears to still be pending on: #363

from flatbuffers.

please explain me how to build flatc executable?

from flatbuffers.

@gaurimaheshwari : https://google.github.io/flatbuffers/flatbuffers_guide_building.html

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