Need help with searching Categories

[vincej]

Hi - I am struggling to find a solution to a category problem.  

 

Perhaps I am over thinking this. I need to display a navigation menu in tabs so that as you tab through the hierarchy you can see the categories in the hierarchy both above and below where you currently are. 

 

 

Conceptually I found an architectural solution on Sitepoint called, Modified Preorder Tree Traversal - but it is quite complex and I was hoping for something a little easier. 

 

In simple terms I need to be able to search and display all the categories and sub categories going up or down the category hierarchy. It could be as much as 5 levels deep. 

 

My need is 3 fold: 

 

1 - starting at the root I have to find all the descendants. 

2 - if you start at the bottom of the hierarchy, I need to find all the ancestors. 

3 - Worst of all ... if you start half way down the hierarchy, I need to display both all the ancestors and all the descendants. 

 

Does anyone have some advice or resources I should consider ?? 

 

MANY MANY  Thanks ! 

 

 

 

 

[requinix]

Couple things to take into account:

- How often will you add new categories? Move or remove ones?

- Do you only need all ancestors and all descendants? Will you ever need to know only immediate parents or immediate children?

[Barand]

You need two arrays

 

One - item as key and parent as value

Two - parent as key and array of children as value

 

Then you need two recursive functions to traverse each array

 

Job done.

[vincej]

@requinix   I will rarely need to add or remove categories. And I will never only want immediate ancestors or descendants 

 

One thing that I omitted to mention is that, the number of levels will be of a fixed and known in advance. I need to go down 5 levels. so for example: 

 

Fruit -> Red -> Apples -> Californian -> Red Delicious | Galla | Jersey Mac |    -- 5 levels

 

So, if I click "Fruit" I might see "Fruit | Red |  Green | Yellow"   all in tabs  -- current Root level + the next level

 

If I click "Red"  I might see  "Fruit | Red | Californian | Mexican | Florida  all in tabs  -- 1 ancestor + next level of descendents

 

If I click "California"  I might see "Fruit | Red | Apples | Californian | Red Delicious | Galla | Jersey Mac "  -- 3 ancestors + next level of descendants

 

So the point is the customer can see where he has come from ( ancestors) and where he can go ( descendent ) and with 1 click jump straight back to "Red" if they choose. Also they can see the descendants beyond where they are as well.  

 

So I am thinking a 5 way multi-dimensional array.  

 

I can populate the array in hard code. Where I am coming unstuck is is how best to dynamically pull the correct content out of the array based on what the user clicks. 

 

 

Many Many Thanks for your Help ! 

[requinix]

You're contradicting yourself...

And I will never only want immediate ancestors or descendants

So, if I click "Fruit" I might see "Fruit | Red |  Green | Yellow"   all in tabs  -- current Root level + the next level...

In those cases you do only want immediate descendants. Unless you're talking only about what is visible to the user at a given time - are you constructing the entire menu hierarchy at once and showing/hiding trees as the user accesses the menu?

[vincej]

Fair comment, yes, well pointed out - I will only want immediately descendants however, I do want to see all ancestors, such that t he click can jump multiple steps up the tree in one hit. 

 

 

are you constructing the entire menu hierarchy at once and showing/hiding trees as the user accesses the menu?

 

 

I'm not sure the best way to hold the data ie one node at a time or all in a single big array.

 

I have it working in a cms ( ExpressionEngine) using an extension. But I want to move off ExpressionEngine  and recreate it in PHP somewhere else. 

 

You can see it in a sandbox environment : 

 

http://jacobssoftwareanddesign.com/angelsroofing/index.php/sub_category/roofing

 

 

Many Thanks !