The Field Control Table (FCT) is a storage area defined within the application program area and used during map processing. It is used by the application program to alter the display characteristics of individual fields during output processing and to receive additional information about each field during input processing.
The entries in a given FCT are called Field Control Table Entries (FCTEs). There are three forms of FCTEs, only one of which will exist in any one FCT:
Short form
Long form
Extended form
The short form of the FCTE has only:
FIELD-NAME
The fields in the long form FCTE are:
FIELD-NAME INPUT-FLAG FDC-OVERRIDE
The fields in the extended FCTE are:
FIELD-NAME INPUT-FLAG FDC-OVERRIDE COLOR-OVERRIDE SYMBOL-SET-OVERRIDE
FCTE fields are described in the following table.
Field Name | Offset | Len | Description | |||||||||||||
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FIELD-NAME | 0 | 6 | The name specified must be the same as that specified for a field name within the map being used. If no match is found, the name is ignored. | |||||||||||||
INPUT-FLAG | 6 | 1 | Space Input was entered and is valid. N No data entered for this field. I Invalid data entered. O Overflow. Too much data entered. U Underflow. Too many decimal places entered S Null entry. The field was entered with no data. This can be caused by use of the selector pen, or by entering a keyword with no data. In either case, an FDC of L must have been specified for this field when the map was built, or in the FDC-OVERRIDE entry of the FCTE. D The DUP key was pressed for this field. |
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FDC-OVERRIDE | 7 | 3 | The FDCs entered here are concatenated to the FDCs specified for
the field in the map. The FDCs is then processed. The last FDC specified takes
precedence, if conflicting FDCs exist. A special FDC of I can be placed in any
position of this field and causes this FCTE to be ignored. FDCs are fully described in Field Descriptor Codes |
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COLOR-OVERRIDE | 10 | 2 | The two-character color override replaces the map's color attribute for this field. | |||||||||||||
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SYMBOL-SET-OVERRIDE | 12 | 1 | The symbol set override replaces the map's SYMBOL-SET-ID for this field. |