[Plugin: Smarter Navigation] How to link prev/next post in parent category?

Yes. But, just to be clear:

In this line
} else if (is_category('portfolio')) {
the word “portfolio” refers to category slug/name.

In this line
$_SESSION['history'] = "portfolio";
the word “portfolio” refers to the variable name assigned to history session.

I must be missing something.

This is the way my categories are set up.

Latest (parent)
illustration (child)
photography (child)
painting (child)

I’m not using the index page to display posts. Just category pages like listed above. So latest, illustration, photography, and painting are all category pages.

Hmmm..

Footer:

<?php
$this_category = get_category($cat);
if (is_home() || is_front_page()) {
$_SESSION['history'] =  "latest";
} else if (is_category('latest')) {
$_SESSION['history'] =  "latest";
} else if ($this_category->category_parent == 1) {
$_SESSION['history'] =  "latest subcategory";
}
?>

Single:

<?php
				if(isset($_SESSION['history'])){ // if "history" session exists
if ($_SESSION['history'] == "home" || $_SESSION['history'] == "latest") { // if you come from home or portfolio, use prev/next links plus code
previous_post_link_plus(array('format' => '<span class="prev">%link</span>', 'link' => '? PREV', 'ex_cats' => '9'));
next_post_link_plus(array('format' => '<span class="prev">%link</span>', 'link' => 'NEXT ?', 'ex_cats' => '9'));
} else if ($_SESSION['history'] == "latest subcategory") { // if you come from a portfolio subcategory use native wordpress prev / next links
previous_post_link ('<span class="next">%link</span>','? PREV', TRUE);
next_post_link ('<span class="prev">%link</span>','NEXT ?', TRUE);
}
} else { // if "history" doesn't exist use prev/next links plus code (maybe this code is not necessary)
previous_post_link_plus(array('format' => '<span class="prev">%link</span>', 'link' => '? PREV', 'ex_cats' => '9'));
next_post_link_plus(array('format' => '<span class="prev">%link</span>', 'link' => 'NEXT ?', 'ex_cats' => '9'));
}
?>

Ok. Assuming that “latest” category ID is = 1 and that you ONLY have the mentioned categories, please try with the code as follows.

In footer.php:

<?php
$this_category = get_category($cat);
if (is_category('latest')) {
$_SESSION['history'] =  "visitorComesFromLatest";
}
?>
<?php wp_footer(); ?>

In single.php:

<?php
if(isset($_SESSION['history'])){
if ($_SESSION['history'] == "visitorComesFromLatest") {
previous_post_link ('<span class="prev">%link</span>','PREV', false);
next_post_link ('<span class="next">%link</span>','NEXT', false);
}
} else {
previous_post_link ('<span class="prev">%link</span>','PREV', true);
next_post_link ('<span class="next">%link</span>','NEXT', true);
}
?>

If it makes a difference, I have one more child category: design :o)

Ok, not a problem. If you have another parent categories, you will need to use other code in single.php.

Does it works for you?

I’m so sorry for wasting your time. No, it’s not working.

Mmmmm…

Well, let’s try if session is working. Clear the code you add in single.php and try this:

if(isset($_SESSION['history'])){
echo "<p>Visitor comes from ".$_SESSION['history']."</p>";
}

Tell if you get “Visitor comes from visitorComesFromLatest”.

Yes, I get that.

Perfect! Session is working.

Let’s try again step by step. Tell me if this works:

if(isset($_SESSION['history'])){
if ($_SESSION['history'] == "visitorComesFromLatest") {
previous_post_link ('%link','PREV', false);
next_post_link ('%link','NEXT', false);
}
}

No, it flips back to the parent order. Same thing.

Yes, I know, is working as expected!

Maybe I’m not being clear about what this code does. The code checks if you come from parent category “Latest”. If it finds session = visitorComesFromLatest, you will navigate between posts in parent category order.

But what I you select a child category? You will want to navigate ONLY between posts in same category and not parent order. Right?

Well, to get this working, you will need to put the code as follows:

if(isset($_SESSION['history'])){
if ($_SESSION['history'] == "visitorComesFromLatest") {
previous_post_link ('%link','PREV', false);
next_post_link ('%link','NEXT', false);
}
} else {
previous_post_link ('%link','PREV', true);
next_post_link ('%link','NEXT', true);
}

Try and tell if I’m right.

Yup, what you explained is exactly what I want.

Unfortunately, I tried your code again, and it still doesn’t work.

When I click on a post from the latest category page, it follows latest order.

However, when I click the very same post from a category (ie: illustration) instead of following the illustration order, it follows latest order and ignores the illustration order.

I’m clicking the category links from a sidebar, does this change things?

My Latest category ID is 96 not 1. Where do I put this?

I’m so sorry. I think I wasted your and my time with this. I appreciate your help. I don’t see this working.

Don’t get frustrated! We will get it working (it works for me in the past!).

Before changing code in footer.php, try this way in single.php:

if ($_SESSION['history'] == "visitorComesFromLatest") {
previous_post_link ('%link','PREV', false);
next_post_link ('%link','NEXT', false);
} else {
previous_post_link ('%link','PREV', true);
next_post_link ('%link','NEXT', true);
}

You’re more determined than I am!

No, it doesn’t work.

Just to be curious..Where are you from? I suspect that we share similar time zones.

Ok, let’s try this:

In footer.php

<?php
$this_category = get_category($cat);
if (is_category('latest')) {
$_SESSION['history'] =  "visitorComesFromLatest";
} else if ($this_category->category_parent == 96) {
$_SESSION['history'] =  "visitorComesFromLatestSubcategory";
}
?>
<?php wp_footer(); ?>

In single.php

if(isset($_SESSION['history'])){
echo "<p>Visitor comes from ".$_SESSION['history']."</p>";
}

Tell me what you get if you come from Latest category and what you get it you come from Latest subcategory (for example, Illustration).