Make setFormatter of GsonBuilder public

[GoogleCodeExporter]

To be honest I don't think the pretty print option generates a pretty
string. I would like to provide my own JsonFormatter. But both the
interface (JsonFormatter) and the setter (setFormatter) in the GsonBuilder
are package private. Could they be made public?

Original issue reported on code.google.com by b.richt...@gmail.com on 14 Oct 2008 at 7:58

[GoogleCodeExporter]

We kept these objects/methods private on purpose.  We were not happy with its 
API
when we first release GSON, so we did not want to leak it out to the clients of 
this
library and then have to support it forever.

Hopefully we can clean up the API that this interface exposes and then we will
definitely consider exposing this interface and method in GsonBuilder.

Original comment by joel.leitch@gmail.com on 16 Oct 2008 at 5:56

• Added labels: Priority-Low, Type-Enhancement
• Removed labels: Priority-Medium, Type-Defect

[GoogleCodeExporter]

Also, if you have any specific suggestions on how to improve the pretty 
printing, we 
would be happy to incorporate them. Even better, if you can contribute some 
code in 
this regard. 

We also welcome suggestions on the API design in this respect. What API would 
you 
prefer? Would the current API (when made public) meet your needs? Can you live 
with 
it, if we keep the parse tree navigation support private in JsonElement and its 
subtypes? 

Original comment by inder123 on 16 Oct 2008 at 11:33

[GoogleCodeExporter]

I realize I've been a lazy user that has done nothing but complaining till now 
:-) 
I'll enjoy looking into the code to see if I can come up with a suggestion to 
improve
the pretty print. To do some expectation management: No promises though 
regarding any
schedule.

Original comment by b.richt...@gmail.com on 16 Oct 2008 at 2:09

[GoogleCodeExporter]

Hi,

I'm sorry I'm late to the game, but ooh-ooh, let it look (literally) like your 
schema
definition (issue #17:
http://code.google.com/p/google-gson/issues/detail?id=17&sort=type)! Looking at 
the
example in the JSON Schema Proposal, if the user provides a schema string, then
setPrettyPrinting(schema-String) will do exactly what you want. Only the 
developer
"really" knows how s/she wants it to look - using the example again, should
"description" and "type" be on one line or two? Likewise with "properties". 
Well, if
I know I'm only outputting a handful of rows of data, one per line is great. 
However,
I have an example of an organizational tree of employees, which could be in the
hundreds. In my case, I'm not going to be a one-per-line person.

Great stuff.

Steve

Original comment by steven.b...@gmail.com on 8 Dec 2008 at 2:14

[GoogleCodeExporter]

I need a simple human readable formatter for complex objects. Basically a 
format of
one key per line, indentation and the usual stuff. Example:

{
  "foo": "bar",
  "baz": 1,
  "list": [
    "first",
    "second",
    "last"
  ],
  "object": {
    "nested": "value"
  }
}

There's probably as many different opinions on how this is is indented and 
nested as
there are different coding styles - but I just want something that is a bit more
readable for nested structures than a one-liner (or a wrapped one-liner, in the 
case
of the current "pretty" printer).

Original comment by nuutti.k...@gmail.com on 26 Mar 2009 at 10:46

[GoogleCodeExporter]

As a response to inder123's comment I emailed a proposal for the Pretty Print 
to Joel
in October 2008. I thought to share it here as well. 

My suggestion is to add a new method called setJsonFormatter to the GsonBuilder,
which takes a JsonFormatter as an argument. First of all: I (re-)use the name
JsonFormatter. As the current interface called JsonFormatter is not part of the
public API, I think it's ok to use this name.

The JsonFormatter takes, as it does now, care of the formatting of a json 
object tree
to a string. It is constructed via a builder pattern. A simple example could be:

JsonFormatter formatter = new JsonFormatterBuilder()
       .indentUsingSpacesWithSize(4)
       .create();

Gson gson = new GsonBuilder()
       .setJsonFormatter(formatter)
       .create();

The public methods the JsonFormatterBuilder has are:

- indentUsingSpacesWithSize(4) // Undoes a preceding call to indentUsingTabs()
- indentUsingTabs() // Undoes a preceding call to indentUsingSpacesWithSize()
- insertNewLineAfterStartObject()
- insertNewLineBeforeEndObject()
- insertNewLineAfterStartArray()
- insertNewLineBeforeEndArray()
- insertSpaceBeforeComma()
- insertSpaceAfterComma() // Undoes a preceding call to 
insertNewLineAfterComma()
- insertNewLineAfterComma() // Undoes a preceding call to 
insertSpaceAfterComma()
- insertSpaceBeforeColon()
- insertSpaceAfterColon() // Undoes a preceding call to 
insertNewLineAfterColon()
- insertNewLineAfterColon() // Undoes a preceding call to 
insertSpaceAfterColon()
- wrapIfPossibleAfter(80)
- doubleIndentWrappedLines()
- setLineSeparator(...)

Not calling the method setJsonFormatter, uses a default formatter which has a 
compact
output, just like the current output without pretty print is. The current method
'setPrettyPrinting' of the GsonBuilder will (of course) be preserved as a 
convenience
method. It will automatically create a JsonFormatter which, if desired, 
imitates the
current behavior as much as possible.

What worries me a bit is the the responsibilities of the objects seem to be 
mixed up.
Should the Gson object have knowledge of the way it will be formatted? Maybe 
it's
better to do it the other way around. Give a JsonFormatter a Gson object. The 
same
Gson object could then be formatted in different ways, which is currently 
impossible.
But I see no real solution for this given the current API with setPrettyPrint 
and toJson.

Original comment by b.richt...@gmail.com on 27 Mar 2009 at 8:05

[GoogleCodeExporter]

Thanks for the detailed proposal. Even though it is way late in the game for 
Gson
1.3, I will try to see if we can put it in. 

A somewhat simpler approach will be to leave out the JsonFormatterBuilder from 
the
API, and just provide a setFormatter method in GsonBuilder. We will also make
JsonFormatter public. Will that suffice for your needs? Also, does that lock us 
out
of any future enhancements? For example, would there ever be a need to chain 
these
formatters? 

Regarding your comment about taking the responsiblity for formatting out, one 
way to
address it would be to add new methods to Gson: toJsonTree() that return a 
parse tree
instead of String. The primary difference between that and using JsonParser 
directly
is that Gson.toJsonTree applies all the custom serializers. Is that a better 
approach? 

Original comment by inder123 on 27 Mar 2009 at 3:33

• Changed state: Started

[GoogleCodeExporter]

For me, providing setFormatter method in GsonBuilder is quite enough (and making
JsonFormatter public). I can not speak for others, of course. I will also 
create and
submit the verbose formatter I described for public inclusion, with tests.

Original comment by nuutti.k...@gmail.com on 27 Mar 2009 at 4:34

[GoogleCodeExporter]

For now, a quick solution (workaround) I use is to provide a 
JsonDeserializer<String>
(with GsonBuilder#registerTypeAdapter). Most likely this would be an extra
JsonDeserializer, next to the one you need for the 'real' deserialization. 

This extra deserializer outputs a String just the way you want; a pretty one, 
for
instance.

Original comment by b.richt...@gmail.com on 27 Mar 2009 at 5:19

[GoogleCodeExporter]

Original comment by inder123 on 27 Mar 2009 at 7:35

• Added labels: Milestone-Release1.4, Priority-High
• Removed labels: Priority-Low

[GoogleCodeExporter]

I submitted the new formatter as issue 112.

Original comment by nuutti.k...@gmail.com on 29 Mar 2009 at 2:20

[GoogleCodeExporter]

Deferred to a future release. Meanwhile, you can use Gson.toJsonTree and format 
the output yourself.

Original comment by inder123 on 29 Sep 2009 at 9:12

• Added labels: Milestone-Release1.5
• Removed labels: Milestone-Release1.4

[GoogleCodeExporter]

Original comment by inder123 on 1 Nov 2010 at 10:29

• Removed labels: Milestone-Release1.5

[GoogleCodeExporter]

Original comment by inder123 on 3 Nov 2010 at 12:27

• Added labels: Milestone-Undefined

[GoogleCodeExporter]

Obsoleted by JsonWriter.

Original comment by limpbizkit on 29 Dec 2011 at 5:49

• Changed state: WontFix