bson_iter_init(3)

NAME

bson_iter_init() – The bson_iter_init() function shall initialize iter to iterate upon the BSON document bson. Upon initialization, iter is placed before the first element. Callers must call bson_iter_next(), bson_iter_find(), or bson_iter_find_case() to advance to an element.

SYNOPSIS

bool
bson_iter_init (bson_iter_t  *iter,
                const bson_t *bson);

PARAMETERS

iter: A bson_iter_t \&.

bson: A bson_t \&.

DESCRIPTION

The bson_iter_init(3) function shall initialize iter to iterate upon the BSON document bson \&. Upon initialization, iter is placed before the first element. Callers must call bson_iter_next(3) , bson_iter_find(3) , or bson_iter_find_case(3) to advance to an element.

RETURNS

Returns true if the iter was successfuly initialized.

EXAMPLE


static void
print_doc_id(const bson_t *doc)
{
    bson_iter_t iter;
    bson_oid_t oid;
    char oidstr[25];
    if (bson_iter_init(&iter, doc) &&
        bson_iter_find(&iter, "_id") &&
        BSON_ITER_HOLDS_OID(&iter)) {
        bson_iter_oid(&iter, &oid);
        bson_oid_to_string(&oid, oidstr);
        printf("%s
", oidstr);
    } else {
        printf("Document is missing _id.
");
    }
}
/* alternatively */
static void
print_doc_id(const bson_t *doc)
{
    bson_iter_t iter;
    bson_oid_t oid;
    char oidstr[25];
    if (bson_iter_init_find(&iter, doc, "_id") &&
        BSON_ITER_HOLDS_OID(&iter)) {
        bson_iter_oid(&iter, &oid);
        bson_oid_to_string(&oid, oidstr);
        printf("%s
", oidstr);
    } else {
        printf("Document is missing _id.
");
    }
}

COLOPHON

This page is part of libbson. Please report any bugs at https://jira.mongodb.org/browse/CDRIVER.