=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
A possible solution is to either split price sources into simple and complex
ones (where the former do not require records).
-Another would be to have default values for the inpout normally taken from
+Another would be to have default values for the input normally taken from
records (like qty defaulting to 1).
A last one would be to provide an alternative input channel for needed
=item *
Discount sources were implemented as a copy of the prices with slightly
-different semantics. Need to do a real design. A requirement is, that a sinle
+different semantics. Need to do a real design. A requirement is, that a single
source can provide both prices and discounts (needed for price_rules).
=item *
=item *
Composing price sources is disallowed for clarity, but all price sources need
-to be aware of units. This is madness.
+to be aware of units and price_factors. This is madness.
+
+=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
projects / kivitendo-erp.git / blobdiff