Holds a DODS Data Attribute Structure.
The Data Attribute Structure is a set of name-value pairs used to describe the data in a particular dataset. The name-value pairs are called the ``attributes''. The values may be of any of the DODS simple data types (Byte, Int16, UInt16, Int32, UInt32, Float32, Float64, String and URL), and may be scalar or vector. Note that all values are actually stored as String data, making the easy to read/check using a web browser. \label{api:das} A value may also consist of a set of other name-value pairs. This makes it possible to nest collections of attributes, giving rise to a hierarchy of attributes. DODS uses this structure to provide information about variables in a dataset. For example, consider the dataset used in the DDS example earlier. In the following example of a DAS, several of the attribute collections have names corresponding to the names of variables in the DDS example. The attributes in that collection are said to belong to that variable. For example, the #lat# variable has an attribute ``units'' of ``degrees\_north''. \begin{verbatim} Attributes { GLOBAL { String title "Reynolds Optimum Interpolation (OI) SST"; } lat { String units "degrees_north"; String long_name "Latitude"; Float64 actual_range 89.5, -89.5; } lon { String units "degrees_east"; String long_name "Longitude"; Float64 actual_range 0.5, 359.5; } time { String units "days since 1-1-1 00:00:00"; String long_name "Time"; Float64 actual_range 726468., 729289.; String delta_t "0000-00-07 00:00:00"; } sst { String long_name "Weekly Means of Sea Surface Temperature"; Float64 actual_range -1.8, 35.09; String units "degC"; Float64 add_offset 0.; Float64 scale_factor 0.0099999998; Int32 missing_value 32767; } } \end{verbatim} Attributes may have arbitrary names, although in most datasets it is important to choose these names so a reader will know what they describe. In the above example, the ``GLOBAL'' attribute provides information about the entire dataset. Data attribute information is an important part of the the data provided to a DODS client by a server, and the DAS is how this data is packaged for sending (and how it is received). The DAS class is simply a sequence of attribute tables and names. It may be thought of as the top level of the attribute hierarchy.
DAS(AttrTable *attr_table, string name)
Pix first_var()
void next_var(Pix &p)
string get_name(Pix p)
AttrTable* get_table(Pix p)
get\_table()
AttrTable* get_table(const string &name)
AttrTable* get_table(const char *name)
add\_table()
AttrTable* add_table(const string &name, AttrTable *at)
AttrTable* add_table(const char *name, AttrTable *at)
parse()
bool parse(string fname)
bool parse(int fd)
bool parse(FILE *in=stdin)
bool print(ostream &os = cout)
alphabetic index hierarchy of classes
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