USER STORY: Product sort by price and category

[johnamdickson]

Epic: Products & Categories: Filtering, Sorting and Searching #15

User Story: As a user I can select products by price and category from the navbar links so that I can sort as required dependent on my personal preference

Acceptance Criteria:

• A means to sort products on selection of appropriate navbar links.
• A means of rendering result on products page

Tasks:

• [x] Implement logic to sort products by either category or price.
• [x] Render results of the sort on to the product template.

[johnamdickson]

Logic added to sort products by category and price using GET requests from the navbar items. Checked functionality in order.