feat: ajout de l'ajax pour le formulaire

layouts/shortcodes/infolettre.html

@@ -1,5 +1,5 @@
 <hr>
-<form method="post" action="https://infolettre.lestoitsduval.fr/subscription/form" class="infolettre">
+<form method="post" action="https://infolettre.lestoitsduval.fr/subscription/form" class="infolettre" id="infolettre">
     <div>
         <h2>Lettre d'information pour se tenir informé</h2>
         <input type="hidden" name="nonce" />
@@ -20,3 +20,36 @@
         </div>
     </div>
 </form>
+<script type="text/javascript">
+  var form = document.getElementById("infolettre");
+  function handleForm(e) {
+    e.preventDefault();
+    let formData = new FormData(this);
+    let parsedData = {};
+    for(let name of formData) {
+      if (typeof(parsedData[name[0]]) == "undefined") {
+        let tempdata = formData.getAll(name[0]);
+        if (tempdata.length > 1) {
+          parsedData[name[0]] = tempdata;
+        } else {
+          parsedData[name[0]] = tempdata[0];
+        }
+      }
+    }
+
+    let options = {};
+    switch (this.method.toLowerCase()) {
+      case 'post':
+        options.body = JSON.stringify(parsedData);
+      case 'get':
+        options.method = this.method;
+        options.headers = {'Content-Type': 'application/json'};
+      break;
+    }
+
+    fetch(this.action, options).then(r => r.json()).then(data => {
+      console.log(data);
+    });
+  }
+  form.addEventListener('submit', handleForm);
+</script>