This chapter lists the backwards incompatible changes introduced in Jansson 2.0, and the steps that are needed for upgrading your code.
The incompatibilities are not dramatic. The biggest
change is that all decoding functions now require and extra parameter.
Most programs can be modified to work with 2.0 by adding a
0 as the second parameter to all calls of
Jansson 2.0 is backwards incompatible with the Jansson 1.x releases. It is ABI incompatible, i.e. all programs dynamically linking to the Jansson library need to be recompiled. It's also API incompatible, i.e. the source code of programs using Jansson 1.x may need modifications to make them compile against Jansson 2.0.
All the 2.x releases are guaranteed to be backwards compatible for both ABI and API, so no recompilation or source changes are needed when upgrading from 2.x to 2.y.
For future needs, a
flags parameter was added as the
second parameter to all decoding functions, i.e.
json_load_file(). All calls
to these functions need to be changed by adding a
0 as the
second argument. For example:
/* old code */ (input, &error); json_loads /* new code */ (input, 0, &error);json_loads
The underlying C type of JSON integers has been changed from
int to the widest available signed integer type, i.e.
long long or
long, depending on whether
long long is supported on your system or not. This makes
the whole 64-bit integer range available on most modern systems.
jansson.h has a typedef
json_int_t to the underlying integer type.
int should still be used in most cases when dealing with
smallish JSON integers, as the compiler handles implicit type coercion.
Only when the full 64-bit range is needed,
json_int_t should be
The maximum argument of the
JSON_INDENT() macro has been
changed from 255 to 31, to free up bits from the
json_dump_file(). If your code uses a bigger
indentation than 31, it needs to be changed.
Version 2.0 unifies unsigned integer usage in the API. All uses of
unsigned int and
unsigned long have been
size_t. This includes flags, container sizes,
etc. This should not require source code changes, as both
unsigned int and
unsigned long are usually