I am new to ERPNext and frappe. I would like to create an application / module to allow the user to define taxes per item in a quotation. These values will then be also reflected in the invoice. There will be different type of taxes (E.g standard, non standard etc). And the total taxes value will need to be calculated and put inside an account for reporting.
My plan is to create a doctype to define a master value for each of the tax type. Also, for each tax type, the user can set which account head these taxes should go into. Global settings and values will be done here.
Then inside the quotation form, there will be additional columns in the per item row listing such as Tax Type, Tax Rate (%).
The default value of tax rate will be auto set to which tax type is selected (E.g standard, non standard etc). But users can change the value of the tax rate as they wish.
Once the values are entered, there is a summary table which calculates the different type of taxes and show the value. For example,
Tax Type, Total
Non standard, 90
The same applies for invoice except that, invoice doesn’t allow to change the values. Those fields and values will be read only based on what was set in the quotation.
Can this be done without touching the core? How can I insert a custom table and columns to the quotation table via my application? I was looking and saw adding of custom fields but I am not sure if that would work.