rmongodb (version 1.8.0)

mongo.bson.iterator.next: Advance an iterator to the first or next field

Description

Advance a mongo.bson.iterator to the first or next field.

Usage

mongo.bson.iterator.next(iter)

Arguments

iter

A mongo.bson.iterator.

Value

(integer) The type of the next of the field pointed to by the iterator as indicated by the folllowing constants:

• mongo.bson.eoo -- End of Object (0L)
• mongo.bson.double
• mongo.bson.string
• mongo.bson.object
• mongo.bson.array
• mongo.bson.binary
• mongo.bson.undefined
• mongo.bson.oid
• mongo.bson.bool
• mongo.bson.date
• mongo.bson.null
• mongo.bson.regex
• mongo.bson.dbref -- deprecated (follow link for more info)
• mongo.bson.code
• mongo.bson.symbol
• mongo.bson.code.w.scope
• mongo.bson.int
• mongo.bson.timestamp
• mongo.bson.long

See Also

mongo.bson.iterator, mongo.bson.iterator.create, mongo.bson.find, mongo.bson.iterator.key, mongo.bson.iterator.type, mongo.bson.iterator.value, mongo.bson.

Examples

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)

iter <- mongo.bson.iterator.create(b)
# Advance to the "cars" field
while (mongo.bson.iterator.next(iter) != mongo.bson.null)
{
    # NOP
}
print(mongo.bson.iterator.value(iter))

# The above is given for illustrative purposes, but may be performed
# much easier by the following:
iter <- mongo.bson.find(b, "cars")
print(mongo.bson.iterator.value(iter))

# iterate through all values and print them with their keys (names)
iter <- mongo.bson.iterator.create(b)
while (mongo.bson.iterator.next(iter)) { # eoo at end stops loop
    print(mongo.bson.iterator.key(iter))
    print(mongo.bson.iterator.value(iter))
}