mongo.bson.value: Return the value of a mongo.bson field
In jonkatz2/rmongodb: R-MongoDB driver

Description Usage Arguments Details Value See Also Examples

Search a mongo.bson object for a field by name and retrieve its value.

1	mongo.bson.value(b, name)

`b`	A mongo.bson object.
`name`	(string) The name of a field within `b`.

The search parameter may also be a 'dotted' reference to a field in a subobject or array. See examples.

NULL if name is not found;
otherwise, the value of the found field.

This function returns an appropriate R object depending on the type of the field found. This mapping to values is as follows:

`mongo.bson.double`	A double
`mongo.bson.string`	A string
`mongo.bson.object`	(See below).
`mongo.bson.array`	(See below).
`mongo.bson.binary`	A raw object. (See below).
`mongo.bson.undefined`	A mongo.undefined object
`mongo.bson.oid`	A mongo.oid object
`mongo.bson.bool`	A logical
`mongo.bson.date`	A "POSIXct" class object
`mongo.bson.null`	NULL
`mongo.bson.regex`	A mongo.regex object
`mongo.bson.dbref`	Error! (deprecated -- see link)
`mongo.bson.code`	A mongo.code object
`mongo.bson.symbol`	A mongo.symbol object
`mongo.bson.code.w.scope`	A mongo.code.w.scope object
`mongo.bson.int`	An integer
`mongo.bson.timestamp`	A mongo.timestamp object
`mongo.bson.long`	A double

Special handling:

mongo.bson.object: If the object is recognized as a complex value (of the form "r" : double, "i" : double ), a complex value is returned. If the special wrapper as output by
mongo.bson.buffer.append.object() is detected, an appropriately attributed R object is returned; otherwise, a list is returned containing the subfields.

mongo.bson.array: If all fields of the array are of the same atomic type, a vector of that type is returned. (Multidimensinal arrays are detected and the dims attribute will be set accordingly. Arrays of complex values are also detected as above). Otherwise, a list is returned containing the subfields.

mongo.bson.binary: If non-zero, the subtype of the binary data is stored in the attribute "subtype". See mongo.bson.buffer.append.raw().

mongo.bson.iterator.value,
mongo.bson.

buf <- mongo.bson.buffer.create()
# Append a string
mongo.bson.buffer.append(buf, "name", "Joe")
# Append a date/time
mongo.bson.buffer.append(buf, "created", Sys.time())
# Append a NULL
mongo.bson.buffer.append(buf, "cars", NULL)
b <- mongo.bson.from.buffer(buf)

# Display the date appended above
print(mongo.bson.value(b, "created"))

b <- mongo.bson.from.list(list(name="John", age=32L,
     address=list(street="Vine", city="Denver", state="CO")))
print(mongo.bson.value(b, "age")) # print 32
print(mongo.bson.value(b, "address.state")) # print CO

x <- c(1,1,2,3,5)
b <- mongo.bson.from.list(list(fib=x)) # BSON arrays are 0-based
print(mongo.bson.value(b, "fib.4")) # print 5