NxCategoryField

The structure NxCategoryField is defined in NxCoreAPI.h as:


struct NxCategoryField {
    const char*   FieldName;
    const char*   FieldInfo;
    unsigned char Set;
    unsigned char FieldType;
    unsigned char alignment[6];

    union { // field is ONE of the following depending on 'FieldType' member.
        __int64         i64Bit;          // FieldType == NxCFT_64BIT      (1)
        int             i32Bit;          // FieldType == NxCFT_32BIT      (2)
        const char*     StringZ;         // FieldType == NxCFT_STRINGZ    (3)
        double          Double;          // FieldType == NxCFT_DOUBLE     (4)
        NxPrice         nxPrice;         // FieldType == NxCFT_PRICE      (5)
        NxDate          nxDate;          // FieldType == NxCFT_DATE       (6)
        NxTime          nxTime;          // FieldType == NxCFT_TIME       (7)
        NxString*       pnxString;       // FieldType == NxCFT_NxSTRING   (8)
        StringTableItem stringTableItem; // FieldType == NxCFT_STRING_IDX (9) or NxCFT_STRING_MAP (10)
    } data;
};

FieldName

A null-terminated ASCII string for the name of the field.

FieldInfo

Contains any comments about the field, may be empty

Set

Has the value 1 if the field has valid data. The value 0 means the data member is not present.

It is important to note that some categories come through more than once per day. These categories might not contain data in every field, so it is imperative to check the "Set" flag to prevent clearing/modifying data unneccessarily.

For more information on the "Set" flag, review the NxMSG_CATEGORY documentation.

FieldType

Indicates which union member to use to interpret the data. Each field will be one of the following types:

#	Field #define	Type	Name	Comment
1	NxCFT_64BIT	__int64	i64Bit	Used mostly for Total Volume and fields that may exceed 32 bits
2	NxCFT_32BIT	int	i32Bit	Very common. Used for most numbers that are not prices.
3	NxCFT_STRINGZ	const char*	StringZ	null-terminated ASCII string. Used for Company Names, etc.
4	NxCFT_DOUBLE	double	Double	Currently, not used for any field in any category.
5	NxCFT_PRICE	NxPrice	nxPrice	A simple structure containing a 32 bit price with the decimal place indicated by PriceType.
6	NxCFT_DATE	NxDate	nxDate	The structure NxDate used for expiration dates, dividend/split dates, etc.
7	NxCFT_TIME	NxTime	nxTime	The structure NxTime used for last trade time, quote times, etc.
8	NxCFT_NxSTRING	NxString*	pnxString	A pointer to an NxString. Used mostly by Options for a direct link to the underlying.
9	NxCFT_STRING_IDX	StringTableItem	stringTableItem	The structure StringTableItem which indicates the table, and index for a defined string.
10	NxCFT_STRING_MAP	StringTableItem	stringTableItem	Same as NxCFT_STRING_IDX, but index is a series of 32 bits, one for each string in a defined table.

data

Union of all possible values, selected by FieldType.

Example

For example of category usage see here

API Documentation