normalisation blog + gestion images

blog/js/modifier_article.js

@@ -3,6 +3,7 @@ const messages = document.getElementById("messages");
 
 const imgField = document.getElementById("articleImage");
 const titleField = document.getElementById("articleTitle");
+const imgPreview = document.getElementById("imagePreview");
 const contentField = document.getElementById("articleContent");
 const categoryField = document.getElementById("articleCategory");
 const publishedField = document.getElementById("articlePublished");
@@ -31,6 +32,21 @@ function imageValide(file) {
   return ["image/jpeg", "image/png", "image/gif"].includes(file.type);
 }
 
+// Preview image on selection
+imgField.addEventListener("change", function () {
+  const file = imgField.files && imgField.files[0];
+  if (!file || !imageValide(file)) {
+    if (imgPreview) {
+      imgPreview.src = "";
+      imgPreview.classList.add("d-none");
+    }
+    return;
+  }
+  const url = URL.createObjectURL(file);
+  imgPreview.src = url;
+  imgPreview.classList.remove("d-none");
+});
+
 
 form.addEventListener("submit", function (e) {
   e.preventDefault();