我是否需要在同一页面中为两个HTML表单添加前缀输入变量

Question

I'm a bit confused of do I need to prefix form input variables with i.e. ('car_', or 'bike_' corresponding to 'car_make', 'bike_make') or can I use same template for both forms without prefixing variables. And if so, do I still need to prefix the 'submit' field, or having different form name is enough to avoid data collision.

I have these two HTML forms on the same page:

<form action="" name="car_search_form" method="POST">
<input type="hidden" name="make" value="Audi" />
<input type="submit" name="car_do_search" value="Search Car" />
</form>
<form action="" name="bike_search_form" method="POST">
<input type="hidden" name="make" value="Schwinn" />
<input type="submit" name="bike_do_search" value="Search Bike" />
</form>

So, in the end I want to get correct value for $validCarMake via this code:

if(isset($_POST['car_do_search']))
{
     $paramCarMake = isset($_POST['make']) ? sanitize_text_field($_POST['make']) : '';
     $validCarMake = esc_sql($paramCarMake); // For SQL queries only
     // TODO: Add data saving to database
}

Also, I want to understand the decision process of PHP engine. How it does deside which variable to choose - how it know on which button I clicked, and why not it does just submit all forms on the page? Also, if there would be any difference if I'd use "GET" method instead of "POST" besides that the one does put the variable values to URL? And how does the GET case it would process attached image to form submit then (as the maximum URL lenght is 255 chars as I know, and i.e. JPEG 100 kiB image contains thousands of chars. I'm asking this, because I also want to allow not just have that search on site's home page, but also allow to make search from a separate website's some kind of widget.

And the last question - if the HTML form processing differs somehow in PHP 7.X compared to PHP 5.X (i.e. PHP 5.4). I means does it caches somewhere the data, does it sends over the internet the attached images of the both forms and consumes network and server data, or it submit's only the data of the form on which I clicked the button.

Answer 1

As long as you keep the 2 input requests separate having the post arg "make" is completely fine. If you send the args in the same request the 2nd will override the first since it was last set.

As for how php decides on what is first it uses what is called order of precedence. This means what it comes to first it executes first unless explicitly told not to.