Guidelines for Edit Views

Edit views show or edit the fields of an item.

According to MMEX schema, several fields can be NULL, but MMEX Desktop automatically converts NULL to a default value ("" for TEXT, 0 for NUMERIC). Although the schema supports the concept of N/A (not applicable) as different from the default value, the application does not support it. In some cases a default value has the semantic meaning of N/A, but the distinction is not always clear.

TEXT fields may or may not be allowed to be empty by the application ('' is different than NULL and it is always allowed by schema). Sometimes the application does not allow an empty value, even if the schema allows NULL.

NUMERIC fields always have a numeric value in the application. There is no way to define an N/A field without a numeric value. Most NUMERIC fields have a limited valid range; a value out of this range effectively means N/A. The 0 value is often equivalent to N/A.

Field name (label)

• The field name (label) should be concise and informative.
• In most cases the field name defined in database schema is sufficient; if not, use a more informative name, or give a longer explanation in the field value in gray color, when this is empty.

Field value

• The field value should be checked for errors.
• Error messages should end in !. Other hints which are not error messages should not end in !.

Empty field value

• Hints can be shown as text in the field value, but in gray color.
• If an empty value means not applicable, show N/A in gray color.
• If a field cannot or should not be empty, show a hint ending in ! in gray color.
• If a numeric field is empty, show a hint like Default is 0 in gray color.

Non-empty field value

• Errors should be indicated with red color (e.g., with red foreground or background color, or with a red ! marker next to the field value).
• Hints should be shown in small size below the value. Better to be avoided and to be given only when the field is empty (as above).Edit views show or edit the fields of an item.

According to MMEX schema, several fields can be NULL, but MMEX Desktop automatically converts NULL to a default value ("" for TEXT, 0 for NUMERIC). Although the schema supports the concept of N/A (not applicable) as different from the default value, the application does not support it. In some cases a default value has the semantic meaning of N/A, but the distinction is not always clear.

TEXT fields may or may not be allowed to be empty by the application ('' is different than NULL and it is always allowed by schema). Sometimes the application does not allow an empty value, even if the schema allows NULL.

NUMERIC fields always have a numeric value in the application. There is no way to define an N/A field without a numeric value. Most NUMERIC fields have a limited valid range; a value out of this range effectively means N/A. The 0 value is often equivalent to N/A.

Field name (label)

• The field name (label) should be concise and informative.
• In most cases the field name defined in database schema is sufficient; if not, use a more informative name, or give a longer explanation in the field value in gray color, when this is empty.

Field value

• The field value should be checked for errors.
• Error messages should end in !. Other hints which are not error messages should not end in !.

Empty field value

• Hints can be shown as text in the field value, but in gray color.
• If an empty value means not applicable, show N/A in gray color.
• If a field cannot or should not be empty, show a hint ending in ! in gray color.
• If a numeric field is empty, show a hint like Default is 0 in gray color.

Non-empty field value

• Errors should be indicated with red color (e.g., with red foreground or background color, or with a red ! marker next to the field value).
• Hints should be shown in small size below the value. Better to be avoided and to be given only when the field is empty (as above).