Describe the problem that you'd like solved

This issue is a follow-up to #8966 and addresses the need for unique randomness in carousel displays when multiple carousels are present on the same page. The current implementation, which uses sort=random.hourly, results in a shared random order across all carousels. This can lead to repetitive content display, especially when carousels share overlapping content.

Scenario

Consider a scenario where two carousels on the same page display books with some overlap:

• Carousel 1: A, B, C, D, E
• Carousel 2: A, B, F, G, H

Using sort=random.hourly results in a shared random order across both carousels, which can lead to identical content appearing in the same order in both carousels. For example:

• Carousel 1 might display: B, A, E
• Carousel 2 might display: B, A, G

This issue arises because the random seed is shared across all carousels, leading to shared content order.

Current Behavior

The current behavior does not allow for unique randomness within the same hour for each carousel. A workaround involves manually appending a custom seed to the sort parameter (e.g., sort=random.hourly_1 for Carousel 1 and sort=random.hourly_2 for Carousel 2), but this approach is counter-intuitive and requires manual intervention for each carousel.

Desired Behavior

The desired behavior is to have a default randomness that is unique to each carousel on the same page. This means that when sort=random.hourly is used, each carousel should display its content in a different order, ensuring unique content display across carousels. If a specific seed is desired for shared randomness, it should be explicitly specified (e.g., sort=random.hourly_1 for shared randomness).

Proposal & Constraints

A proposed solution involves modifying the sorting logic to automatically generate a unique seed for each carousel when sort=random.hourly is used. This can be achieved by appending a hash of the carousel parameters to the sort parameter, ensuring that each carousel has a unique random order. The code snippet below illustrates this approach:

if not sort.contains('_'):
    json_params_str = json.dumps(carousel_params, sort=true)
    md5_hash = hash_function(json_params_str)
    sort += f'_{md5_hash[:3]}' # Use only a few letters of the hash to prevent excessively large seed space
else:
    # Continue with the existing method for processing custom seeds

This solution aims to simplify the process for librarians and patrons by eliminating the need for manual seed specification for unique randomness. This should lead to a more intuitive experience for librarians and as such better patron experience.

Constraints

When implementing this, we should prioritize keeping the code as simple as possible. We might need to refactor a few methods (words/editions/authors) to ensure that they can all accept the params to use as a seed.

Additional requirements:

• Write unit tests
• Performance testing

Additional context

For further context see: #8966 (comment)

Stakeholders

@cdrini