PHP Web Services

Chapter 2. HTTP Verbs

HTTP verbs such as GET and POST let us send our intention along with the URL so we can instruct the server what to do with it. Web requests are more than just a series of addresses, and verbs contribute to the rich fabric of the journey.

I mentioned GET and POST because it’s very likely you’re already familiar with those. There are many verbs that can be used with HTTP—in fact, we can even invent our own—but we’ll get to that later in the chapter (see Using Other HTTP Verbs). First, let’s revisit GET and POST in some detail, looking at when to use each one and what the differences are between them.

Making GET Requests

URLs used with GET can be bookmarked, they can be called as many times as needed, and the request should not affect change to the data it accesses. A great example of using a GET request when filling in a web form is when using a search form, which should always use GET. Searches can be repeated safely, and the URLs can be shared.

Consider the simple web form in Figure 2-1, which allows users to state which category of results they’d like and how many results to show. The code for displaying the form and the (placeholder) search results on the page could be something like this:

<?php

if(empty($_GET)) {

?>

<form name="search" method="get">
    Category:
    <select name="category">
        <option value="entertainment">Entertainment</option>
        <option value="sport">Sport</option>
        <option value="technology">Technology</option>
    </select> <br />

    Rows per page: <select