Generate navigation from a multi-dimensional array - php

Question

The question: How do I generate navigation, allowing for applying different classes to different sub-items, from a multi-dimensional array?
Here is how I was doing it before I had any need for multi-level navigation:
Home
Pics
About
and was generated by calling nav():
function nav(){
$links = array(
"Home" => "home.php",
"Pics" => "pics.php",
"About" => "about.php"
);
$base = basename($_SERVER['PHP_SELF']);
foreach($nav as $k => $v){
echo buildLinks($k, $v, $base);
}
}
Here is buildLinks():
function buildLinks($name, $page, $selected){
if($selected == $page){
$theLink = "<li class=\"selected\">$name</li>\n";
} else {
$thelink = "<li>$name</li>\n";
}
return $thelink;
}
My question, again:
how would I achieve the following nav (and notice that the visible sub navigation elements are only present when on that specific page):
Home
something1
something2
Pics
About
and...
Home
Pics
people
places
About
What I've tried
From looking at it it would seem that some iterator in the SPL would be a good fit for this but I'm not sure how to approach this. I have played around with RecursiveIteratorIterator but I'm not sure how to apply a different style to only the sub menu items and also how to only show these items if you are on the correct page.
I built this array to test with but don't know how to work with the submenu1 items individually:
$nav = array(
array(
"Home" => "home.php",
"submenu1" => array(
"something1"=>"something1.php",
"something2" => "something2.php")
),
array("Pics" => "pics.php"),
array("About" => "about.php")
);
The following will print out the lot in order but how do I apply, say a class name to the submenu1 items or only show them when the person is on, say, the "Home" page?
$iterator = new RecursiveIteratorIterator(new RecursiveArrayIterator($nav));
foreach($iterator as $key=>$value) {
echo $key.' -- '.$value.'<br />';
}
And this gets me:
Home
something1
something2
Pics
About
But I have no way to apply classes to those sub items and no way to only display them conditionally because I don't see how to target just these elements.

Answer 1

Don't reinvent the wheel, use Zend_Navigation and you will be happy.

Answer 2

You were on the right track with RecursiveIteratorIterator. It essentially flattens a recursive iterator. Here is the correct way:
$nav = array(
array(
"Home" => "home.php",
"submenu1" => array(
"something1"=>"something1.php",
"something2" => "something2.php")
),
array("Pics" => "pics.php"),
array("About" => "about.php"),
);
$it = new RecursiveIteratorIterator(
new RecursiveArrayIterator($nav),
RecursiveIteratorIterator::SELF_FIRST
);
foreach ($it as $k => $v) {
if ($it->getDepth() == 0)
continue;
echo str_repeat(" ", $it->getDepth() - 1) .
"$k => $v\n";
}
gives
Home => home.php
submenu1 => Array
something1 => something1.php
something2 => something2.php
Pics => pics.php
About => about.php

Answer 3

It seems like you might want to do this in a more object oriented way.
If not, it seems like you should at least define an algorithm that makes sense, right now you are just blindly guessing. Instead, DEFINE.
For example:
I am defining my navigation to be a php hash based tree. A navigation item will have the following:
A) if there is a top level link, the array hash will contain an item(sub array) labeled "navigation leaf"
b) A navigation Leaf will contain elements labeled "Display value", "link value", and "alt value". These items will be used to generate an anchor tag.
c) if an element has a submenu, in addition to containing a "Navigation Leaf", a "subnavigation" element will be present. A subnavigation element will have a "Navigation Leaf" if it has a displayable navigation item.
You can then write functions/methods that will display your navigation based on the definition you choose.

Answer 4

What I would do, is something along these lines:
class MenuItem {
protected $active = false;
protected $children = array();
protected $name = '';
protected $link = '';
public function __construct($name, $link, $active) {}
public function __toString() {
//render this item
$out = ''; #render here
if (!$this->isActive()) {
return $out;
}
$out .= '<ul>';
foreach ($this->children as $child) {
$out .= (string) $child;
}
$out .= '</ul>';
return $out;
}
public function isActive() {
if ($this->active) {
return true;
}
foreach ($this->children as $child) {
if ($child->isActive()) {
return true;
}
}
return false;
}
}
Then, all you have is a collection of root menu items in an array... To build your menu, you just do:
$rootItems = array($item1, $item2);
$out = '<ul>';
foreach ($rootItems as $item) {
$out .= (string) $item;
}
$out .= '</ul>';
I'll leave the semantics of constructing the object, adding children, etc to the user...

Answer 5

What about rewrite nav function in the next way:
function nav($links, $level){
foreach($links as $k => $v) {
if (is_array($v)) {
nav($v, $level + 1)
} else {
echo buildLinks($k, $v, $base);
}
}
}
And than call it:
$links = array(
array(
"Home" => "home.php",
"submenu1" => array(
"something1"=>"something1.php",
"something2" => "something2.php")
),
array("Pics" => "pics.php"),
array("About" => "about.php")
);
nav($links, 0);

Answer 6

Simplest way, IMHO, is to just make a recursive call, and use a tree structured description of your navigation (that is, nested arrays). Untested example code:
<?php
$links = array(
"Home" => array("home.php", array(
"something1"=> array("something1.php", array()),
"hello"=> array("hello.php", array(
"world" => array("world.php", array()),
"bar" => array("bar.php", array()),
)),
)),
"Pics" => array("pics.php", array(
"people"=>"people.php",
"places" => "places.php",
)),
"About" => array("about.php", array()), // example no subitems
);
// use the following $path variable to indicate the current navigational position
$path = array(); // expand nothing
$path = array('Home'); // expand Home
$path = array('Home', 'hello'); // also expand hello in Home
// map indent levels to classes
$classes = array(
'item',
'subitem',
'subsubitem',
);
// recursive function to build navigation list
function buildNav($links, $path, $classes)
{
// selected page at current level
// NOTE: array_shift returns NULL if $path is empty.
// it also alters the array itself
$selected = array_shift($path);
$class = array_shift($classes);
echo "<ul>\n";
foreach($links as $name => $link)
{
list($href, $sublinks) = $link;
if ($name == $selected)
{
echo "<li class=\"selected $class\">$name\n";
// recursively show subitems
// NOTE: path starts now with the selected subitem
buildNav($sublinks, $path, $classes);
echo "</li>\n";
}
else
{
echo "<li>$name</li>\n";
}
}
echo "<ul>\n";
}
// actually build the navigation
buildNav($links, $path, $classes);
?>

Answer 7

#catchmeifyoutry
Thank you, you saved my life LoL.
I changed your function a little to adapt it to my use and this came out:
$html['navi'] = array(
"Home" => "/home/",
"DJs & Shows" => "/djs-shows/",
"Playlists" => "/playlists/",
"Newsbeat" => "/newsbeat/",
"Reviews" => "/reviews/",
"TV" => "/tv/",
"Contact" => "/contact/",
"Test" => array("/test/",
array("Submenu 1" => "/test/link1",
"Submenu 2" => "/test/link2",
"Submenu 3" => "/test/link3",
"Submenu 4" => "/test/link4",
"Submenu 5" => "/test/link5",
"Submenu 6" => "/test/link6"
)
)
);
$classes = array(
'first-level',
'second-level',
'third-level',
);
function siteNavi($links, $classes) {
// The best way for MultiArray navigation (LOVE IT!)
// Array Shift selects first element and removes it from array
$class = array_shift($classes);
echo "<ul class=\"$class\">\n";
foreach($links as $name => $link) {
if (is_array($link) AND $class != "") {
list($link, $sublinks) = $link;
if ($_GET['site'] == basename($link)) { $selected = ' class="current"'; } else { $selected = ""; }
echo "<li{$selected}>{$name}\n";
// recursively show subitems
// NOTE: path starts now with the selected subitem
siteNavi($sublinks, $classes);
echo "</li>\n";
} else {
if ($_GET['site'] == basename($link)) { $selected = ' class="current"'; } else { $selected = ""; }
echo "<li{$selected}><a href=\"{$link}\" >{$name}</a></li>\n";
}
}
echo "</ul>\n";
}
Thank you very much !
I wonder how much impact does have this kind of code on the page speed tho. Few microseconds of milliseconds :D