Hi, On Sat, Oct 31, 2009 at 11:07 AM, MEM <talofo@xxxxxxxxx> wrote: > > > *From:* Lex Braun [mailto:lex.braun@xxxxxxxxx] > *Sent:* sábado, 31 de Outubro de 2009 14:05 > *To:* MEM > *Cc:* php-general@xxxxxxxxxxxxx > *Subject:* Re: RE: Help with my first recursion menu > > > > Hi, > > On Wed, Oct 28, 2009 at 5:22 PM, MEM <talofo@xxxxxxxxx> wrote: > > I've been told that stack is the way to go, so I'm trying to understand the > following code: > http://pastebin.com/m5616c88f > I've commented every line so that any of you could see if I'm interpreting > something wrong: > > > I have two questions about this code, that hopefully someone on the list > could explain: > > 1) > Why do we need to remove the last array item? (on line 32): > array_pop($urlStack); > > On line 20, $url creates an URL path that includes the $cat path. Once > you've completed iteration on all children of $cat, the url path should no > longer include $cat path, thus it is removed from $urlStack. > > > > > 2) > Why we print the closed tag of the li element, after the recursive call? > (on > line 29) > echo "</li>\n"; > > Line 29 is closing the li element that was opened on line 23 for $cat. > > > > Thanks a lot in advance, > Márcio > > -Lex > > > > > > > > > > Thanks a lot. I knew that: > > “Line 29 is closing the li element that was opened on line 23 for $cat.” > > > > My question intend to be more like: > > Why that line to close the li element is **after** the recursive call? > > Somehow, it seems that instead of creating something like this: > > <ul> > > <li>item1</li> > > <li>item2</li> > > <li>item3</li> > > </ul> > > > > We are doing: > > <ul> > > <li>item1 > > <li>item2 > > <li>item3 > > </li> > > </ul> > > > Say you have a tree menu that contains : $arr = array('item1' => 'Item 1', 'item2' => array('item2a' => 'Item 2a', 'item2b' => 'Item 2b')); $urlStack = array('category'); When you call the tree() function with the above $arr values, the function acts as follows: 1. First time through the function, the opening ul element is printed 2. First time through the foreach loop sets $cat = 'item1' and $val = 'Item 1'. 3. As this is not an array, the else condition prints <li>Item 1</li> 4. Second time through the foreach loop sets $cat = 'Item 2' and $val = array('item2a' => 'Item 2a', 'item2b' => 'Item 2b'). 5. As this is an array, the if condition prints <li><a href=''>Item</a> and calls the tree function recursively 6. Second time through the tree function, another <ul> element is printed and the two sub items are printed as <li>sub item</li> as they do not contain additional arrays. Tree function ends by printing the closing </ul> tag. 7. The foreach loop from step 5 continues and prints the closing </li>. Tree function ends by printing the closing </ul> tag. The output from calling tree($arr, $urlStack) would thus be: <ul> <li>Item 1</li> <li> <a href="?path=category/Item 2">Item 2</a> <ul> <li>Item 2a</li> <li>Item 2b</li> </ul> </li> </ul>
