Master / Detail attributes
When a document has identical fields in its header and lines, these fields interact in a specific manner.
An example is the Store field in the sales order header and lines.
If a field in the document header has a value, you need to make sure that the corresponding field in the document lines contains the same value. On the other hand, if the different lines contain different values, the document's header field should be empty.
When this principle isn't obeyed and the Store field in the document header contains a value despite the document lines having different store values, you may look in the header and think that this store applies to all of its lines as well, which may not be true.
Concepts and rules
To make sure the main principles are followed, requirements and rules apply to each set of Master/Detail fields.
Concepts
- In order to allow different lines to contain different stores and at the same time follow the main principle, you need to make sure that the Store field in the document header contains empty (NULL) values.
Such values are set only when the document lines have different values. In contrast, the value in the field in the document lines is required/mandatory (TRUE) and must always contain a value.
- The main/leading field is the required/mandatory field in the lines. It's set to always contain a value.
For example, if you're generating a store order from a sale order, the Store field taken into account is the one in the sales order lines. You need to create a separate store order for each store line in order to execute the sales order correctly. Keep in mind that in store orders, there's only one Store field, and it's in the header.
- If the document doesn't contain any lines, then there's no limitation for the document header value.
It doesn't matter if it's empty (NULL) or if it contains a value (not-NULL).
Front-end rules
When the value of a document header's field is changed, it's automatically set to ALL document lines.
When all document lines have the same value in the Store field, the field in the document header must contain the same value.
The presence of a value in the document header field makes it unnecessary to constantly monitor whether the lines have different values or not. When editing the value in the Line Store field or deleting lines, if it turns out that all lines contain the same Store value, this value is automatically set in the document header field.
- When different document lines have different values in the Store field, the field in the document header must be empty (NULL).
For this reason, after editing the value in the Line Store field and when deleting lines, if it turns out that the line contains a different Store value, then this value is automatically set as empty in the document header.
- When adding a new line, you're setting the default value in the Line Store field, which equals the one in the document header (unless another default value is explicitly set).
If the document header value is empty (NULL), the value from the previous lines is considered as a default value in the new line. If this is impossible, then the default value remains empty (NULL).
Back-end rules
When the document header is saved, the master/detail field's value is updated according to the value of the lines field. If all lines contain the same Store value, it's automatically set in the document header field. If the lines contain different Store values, the Store field is automatically set to NULL.
When а document line is saved, the master/detail field's value is updated according to the value of the field in the header.
When the document's header and lines are saved, there is a final back-end validation.
If it turns out that despite the rules above, the values of the master/detail fields are invalid, an error is thrown:
The master attribute '{the name of the field in the header}' should have the same values as the detail '{the name of the field in the lines}' attribute for all lines or null, if there are different values through the lines.