=item 2.
-If a price is set from a source, it is read only. A price edited manually is by
-definition not a sourced price.
+If a price is set from a source then the system will try to prevent the user
+from messing it up. By default this means the price will be read-only.
+Implementations can choose to make prices editable, but even then deviations
+from the calculatied price will be marked.
+
+A price that is not set from a source will not have any of this.
=item 3.
=head1 STRUCTURE
Price sources are managed by this package (L<SL::PriceSource>), and all
-external access should be by using it's interface.
+external access should be by using its interface.
Each source is an instance of L<SL::PriceSource::Base> and the available
implementations are recorded in L<SL::PriceSource::ALL>. Prices and discounts
returned by interface methods are instances of L<SL::PriceSource::Price> and
-L<SL::PriceSource::Discout>.
+L<SL::PriceSource::Discount>.
Returned prices and discounts should be checked for entries in C<invalid> and
C<missing>, see documentation in their classes.
=item C<best_price>
-Attempts to get the best available price. returns L<empty_price> if no price is found.
+Attempts to get the best available price. returns L<empty_price> if no price is
+found.
=item C<best_discount>
-Attempts to get the best available discount. returns L<empty_discount> if no discount is found.
+Attempts to get the best available discount. returns L<empty_discount> if no
+discount is found.
=item C<empty_price>
-A special empty price, that does not change the previously entered price, and
+A special empty price that does not change the previously entered price and
opens the price field to manual changes.
=item C<empty_discount>
-A special empty discount, that does not change the previously entered discount, and
-opens the discount field to manual changes.
+A special empty discount that does not change the previously entered discount
+and opens the discount field to manual changes.
=back
=item *
-A common complaint is that prices from certain vendors are always negotiated
-and should use a default value but must be editable (like free prices) by
-default. This should be orthogonal for all prices.
-
-=item *
-
The current implementation of lastcost is useless. Since it's one of the
master_data prices it will always compete with listprice. But in real scenarios
the listprice tends to go up, while lastcost stays the same, so lastcost
usually wins. Lastcost could be lower priority, but a better design would be
nice.
+=item *
+
+Guarantee 1 states that price sources will never change prices on their own.
+Further testing in the wild has shown that this is desirable within a record,
+but not when copying items from one record to another within a workflow.
+
+Specifically when changing from sales to purchase records prices don't make
+sense anymore. The guarantees should be updated to reflect this and
+transposition guidelines should be documented.
+
+The previously mentioned linked prices can emulated by allowing price sources
+to set a new price when changing to a new record in the workflow. The decision
+about whether a price is eligable to be set can be suggested by the price
+source implementation but is ultimately up to the surrounding framework, which
+can make this configurable.
+
+=item *
+
+Prices were originally planned as a context element rather than a modal popup.
+It would be great to have this now with better framework.
+
+=item *
+
+Large records (30 positions or more) in combination with complicated price
+sources run into n+1 problems. There should be an extra hook that allows price
+source implementations to make bulk calculations before the actual position loop.
+
=back
=head1 AUTHOR
projects / kivitendo-erp.git / blobdiff