Wordpress do_shortcode first iteration

Question

I've created a recursive shortcode that looks like this.

[tabs]
[tab state="active"]Home[/tab]
[tab]About[/tab]
[tab]Contact[/tab]
[/tabs]

[tabcontent]
[tabpane]Content 1[/tabpane]
[tabpane]Content 2[/tabpane]
[tabpane]Content 3[/tabpane]
[/tabcontent]

It is working, but I would like to remove the state="active" and automatically add that to the first tab, but I'm not sure how to tell which iteration my do_shortcode is on?

Update: What would be even better is if I could keep a count while iterating through the do_shortcode so I could add attributes like id="tab1", id="tab2".

Answer 1

Figured out both issues. You can keep a count and find out when you are on the first iteration in the same go.

static $count;
if(!$count) {
    $count = 1;
    $state = ' active';
} else {
    $count++;
    $state = '';
}

From the PHP Manual. "A static variable exists only in a local function scope, but it does not lose its value when program execution leaves this scope."

This code sets a static variable within the recursive function, in this case a function called by do_shortcode(). This lets you keep a count going so if you wanted to have id's like #tab-1, #tab-2 you could easily do so. With this code you can also tell when the first iteration happens. I set a $state variable and give it an active css class. Since I'm appending it to a class attribute already I've only got active, but you could also pass the whole thing if you only had one class like class="active" for example.