Algorithm Paging

Creating Dynamic Paging Links - Simplifying Navigation for Users

Paging links are essential for enhancing navigation in applications that display lists of items, such as forums or galleries. Creating a seamless paging experience helps users move between pages without confusion. In this blog post, we will explore the problem of generating these dynamic paging links and provide a robust solution.

When designing a system to display content across multiple pages, a central question arises: How do we generate the links that allow users to navigate between these pages effectively?

For example, when a user is on page 7 of 593, how should the paging links be constructed? A common layout might look like:

1 ... 5 6 7 ... 593

In the layout above, users can see the first page (1), the current page (7), and the last page (593), along with adjacent pages (5 and 6). This format keeps navigation concise and user-friendly.

Below is a structured approach to create dynamic paging links. We will first outline the traits to consider in the algorithm, and then provide pseudo-code to illustrate how to implement it.

Key Traits of the Paging Algorithm

  1. Display a link to the previous page (Prev) if the user is not on the first page.
  2. Always display the first page number.
  3. Show the current page number.
  4. Include the page before and after the current page.
  5. Display the last page number.
  6. Show a link to the next page (Next) if the user is not on the last page.

The initial algorithm is a good starting point. We’ll check various edge cases and refine the approach based on those circumstances.

function printPageLinksFirstTry(num totalPages, num currentPage)
  if (currentPage > 1)
    print "Prev"
  print "1"
  print "..."
  print currentPage - 1
  print currentPage
  print currentPage + 1
  print "..."
  print totalPages
  if (currentPage < totalPages)
    print "Next"
endFunction

Handling Edge Cases: Refining the Logic

We need to account for when the current page is close to the edges of the range. For this, we can modify the previous function:

function printPageLinksHandleCloseToEnds(num totalPages, num currentPage)
  if (currentPage > 1)
    print "Prev"
  print "1"
  if (currentPage > 2)
    print "..."
  if (currentPage > 2)
    print currentPage - 1
  print currentPage
  if (currentPage < totalPages - 1)
    print currentPage + 1
    print "..."
  print totalPages
  if (currentPage < totalPages)
    print "Next"
endFunction

Cleanup: Streamlining the Code

As we refine further, we can reduce redundancy in the code:

function printPageLinksCleanedUp(num totalPages, num currentPage)
  if (currentPage > 1)
    print "Prev"
  print "1"
  if (currentPage > 2)
    print "..."
    print currentPage - 1
  print currentPage
  if (currentPage < totalPages - 1)
    print currentPage + 1
    print "..."
  print totalPages
  if (currentPage < totalPages)
    print "Next"
endFunction

Final Adjustments: Accommodating All Scenarios

Finally, let’s make sure everything works correctly even when there are only a few pages:

function printPageLinksFinal(num totalPages, num currentPage)
  if (totalPages == 1)
    return

  if (currentPage > 1)
    print "Prev"

  print "1"

  if (currentPage > 2)
    print "..."
    print currentPage - 1

  if (currentPage != 1 and currentPage != totalPages)
    print currentPage

  if (currentPage < totalPages - 1)
    print currentPage + 1
    print "..."

  print totalPages

  if (currentPage < totalPages)
    print "Next"
endFunction

Conclusion

By following the steps outlined above, you can implement a robust algorithm for generating dynamic paging links that will significantly improve user navigation on your website. Implementing such an algorithm allows users to move through content seamlessly, ensuring a much more enjoyable browsing experience.

We hope this guide empowers you to create effective paging links in your application!