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.Dd April 20, 2025
.Dt PROP_OBJECT 3
.Os
.Sh NAME
.Nm prop_object ,
.Nm prop_object_retain ,
.Nm prop_object_release ,
.Nm prop_object_type ,
.Nm prop_object_equals ,
.Nm prop_object_iterator_next ,
.Nm prop_object_iterator_reset ,
.Nm prop_object_iterator_release ,
.Nm prop_object_externalize ,
.Nm prop_object_externalize_with_format ,
.Nm prop_object_externalize_to_file ,
.Nm prop_object_externalize_to_file_with_format ,
.Nm prop_object_internalize ,
.Nm prop_object_internalize_from_file
.Nd general property container object functions
.Sh LIBRARY
.Lb libprop
.Sh SYNOPSIS
.In prop/proplib.h
.\"
.Ft void
.Fn prop_object_retain "prop_object_t obj"
.Ft void
.Fn prop_object_release "prop_object_t obj"
.\"
.Ft prop_type_t
.Fn prop_object_type "prop_object_t obj"
.Ft bool
.Fn prop_object_equals "prop_object_t obj1" "prop_object_t obj2"
.\"
.Ft prop_object_t
.Fn prop_object_iterator_next "prop_object_iterator_t iter"
.Ft void
.Fn prop_object_iterator_reset "prop_object_iterator_t iter"
.Ft void
.Fn prop_object_iterator_release "prop_object_iterator_t iter"
.\"
.Ft char *
.Fn prop_object_externalize "prop_object_t obj"
.Ft char *
.Fn prop_object_externalize_with_format "prop_object_t obj" \
    "prop_format_t format"
.Ft bool
.Fn prop_object_externalize_to_file "prop_object_t obj" "const char *path"
.Ft bool
.Fn prop_object_externalize_to_file_with_format "prop_object_t obj" \
    "const char *path" "prop_format_t format"
.\"
.Ft prop_object_t
.Fn prop_object_internalize "const char *data"
.Ft prop_object_t
.Fn prop_object_internalize_from_file "const char *path"
.Sh DESCRIPTION
The
.Nm
family of functions operate on all property container object types.
.Bl -tag -width ""
.It Fn prop_object_retain "prop_object_t obj"
Increment the reference count on an object.
.It Fn prop_object_release "prop_object_t obj"
Decrement the reference count on an object.
If the last reference is dropped, the object is freed.
.It Fn prop_object_type "prop_object_t obj"
Determine the type of the object.
Objects are one of the following types:
.Pp
.Bl -tag -width "PROP_TYPE_DICT_KEYSYM" -compact
.It Dv PROP_TYPE_BOOL
Boolean value
.Pq prop_bool_t
.It Dv PROP_TYPE_NUMBER
Number
.Pq prop_number_t
.It Dv PROP_TYPE_STRING
String
.Pq prop_string_t
.It Dv PROP_TYPE_DATA
Opaque data
.Pq prop_data_t
.It Dv PROP_TYPE_ARRAY
Array
.Pq prop_array_t
.It Dv PROP_TYPE_DICTIONARY
Dictionary
.Pq prop_dictionary_t
.It Dv PROP_TYPE_DICT_KEYSYM
Dictionary key symbol
.Pq prop_dictionary_keysym_t
.El
.Pp
If
.Fa obj
is
.Dv NULL ,
then
.Dv PROP_TYPE_UNKNOWN
is returned.
.It Fn prop_object_equals "prop_object_t obj1" "prop_object_t obj2"
Returns
.Dv true
if the two objects are of the same type and are equivalent.
.It Fn prop_object_iterator_next "prop_object_iterator_t iter"
Return the next object in the collection
.Pq array or dictionary
being iterated by the iterator
.Fa iter .
If there are no more objects in the collection,
.Dv NULL
is returned.
.It Fn prop_object_iterator_reset "prop_object_iterator_t iter"
Reset the iterator to the first object in the collection being iterated
by the iterator
.Fa iter .
.It Fn prop_object_iterator_release "prop_object_iterator_t iter"
Release the iterator
.Fa iter .
.It Fn prop_object_externalize "prop_object_t obj"
Externalizes an object, returning a NUL-terminated buffer containing
a representation of the object in the default format
.Pq XML property list .
The caller is responsible for freeing the returned buffer.
If converting to the external representation fails for any reason,
.Dv NULL
is returned.
.Pp
In user space, the buffer is allocated using
.Xr malloc 3 .
In the kernel, the buffer is allocated using
.Xr malloc 9
using the malloc type
.Dv M_TEMP .
.It Fn prop_object_externalize_with_format "prop_object_t obj" \
    "prop_format_t format"
Like
.Fn prop_object_externalize ,
except the output format is specified explicitly.
The following formats are supported:
.Pp
.Bl -tag -width "PROP_FORMAT_JSON" -compact
.It Dv PROP_FORMAT_JSON
RFC 8259 JSON format
.It Dv PROP_FORMAT_XML
XML property list format
.El
.It Fn prop_object_externalize_to_file "prop_object_t" \
    "const char *path"
.It Fn prop_object_externalize_to_file_with_format "prop_object_t" \
    "const char *path" "prop_format_t format"
Like
.Fn prop_object_externalize
and
.Fn prop_object_externalize_with_format ,
except the external representation is written to the file specified by
.Fa path .
The file is saved with the mode
.Dv 0666
as modified by the process's file creation mask
.Pq see Xr umask 2
and is written atomically.
Returns
.Dv false
if externalizing the object or writing the file fails for any reason.
.It Fn prop_object_internalize "const char *data"
Parses the external representation of an object in the NUL-terminated
buffer
.Fa data
and returns the corresponding object.
The format of the external representation is detected automatically.
Returns
.Dv NULL
if parsing fails for any reason.
.It Fn prop_object_internalize_from_file "const char *path"
.El
.Sh SEE ALSO
.Xr prop_array 3 ,
.Xr prop_bool 3 ,
.Xr prop_data 3 ,
.Xr prop_dictionary 3 ,
.Xr prop_number 3 ,
.Xr prop_string 3 ,
.Xr proplib 3
.Sh HISTORY
The
.Xr proplib 3
property container object library first appeared in
.Nx 4.0 .