Edit news article

Because mistakes can be made when creating a news article, we need an edit functionality so that news articles can be edited. For this, we will re-use the create news article template, and define a new controller method to handle the saving of the edited news article.

Setting up the route

As same as with the Add news article page, we will also use one route to handle both the display of the edit page, as well as handle the editing itself:

$this->_routes[] = [
    "uri"       =>  "news/[:params:]/edit",
    "method"    =>  Route::METHOD_GET | Route::METHOD_POST,
    "action"    =>  function (
        Request $request,
        Response $response,
        Application $app
    ) {
        $newsModel = $app["loadModel.service"]("News");
        $newsView = $app["loadView.service"]("CreateNews", $newsModel);
        $newsController = new \App\Controller\News($newsModel);
        if ($request->getMethod() === "POST"
            && $newsController->edit($request, $response, $newsView)
        ) {
            return;
        }
        $newsController->loadEdit($request->query, $newsView);
        $newsView->addSubView("head", $app["loadView.service"]("Head"))
            ->addSubView("foot", $app["loadView.service"]("Foot"))
            ->render();
    }
];

We have the route prepared, and as you can see we will just re-use a lot of the code in already written in the Controller and the View, for which we will only need to make minor adjustments.

Preparing the View

We already have the Template ready as we need it. It is already made so it presents data if it is set from the ref:add news article section. We will just need to extend the View class to obtain the data from the model and set it to view data before it is rendered. We need to make sure that the model is optional, since we are using the same View for the Create News Article page, which does not require a model:

protected $newsModel = null;

public function init(\App\Model\News $newsModel = null): CreateNews
{
    $this->newsModel = $newsModel;
    return $this;
}

public function preRender(array $data)
{
    if ($this->newsModel !== null && isset($this->viewData["error"]) === false) {
        $article = $this->newsModel->select(["title", "body"]);
        if ($article->row(1)) {
            $this->viewData["title"] = $article->title;
            $this->viewData["body"] = $article->body;
        }
    }

    $this->viewData["error"] = $this->viewData["error"] ?? "";
    $this->viewData["title"] = $this->viewData["title"] ?? "";
    $this->viewData["body"] = $this->viewData["body"] ?? "";
    $this->viewData["actionUrl"] = $this->viewData["actionUrl"] ?? "/create/news";
}

We are assigning the News Model object to the View Class properties in the init method, and we have extended the preRender method, to obtain the news article data from the News Model before the page is being rendered. We could theoretically already begin editing, but we need to make two slight alterations. One is to add a link to the edit page into the single page Template SingleNews.php:

<div class="news-article">
    <h1><?= $article->title; ?></h1>
    <p><?= $article->body; ?></p>
    <span class="edit-link"><a href="/news/<?= $article->id; ?>/edit">Edit</a</span>
</div>

And in order for our form to properly send the edit and save POST requests, we will need to dynamically set it in the Controller as view data and print it out in the Template file CreateNews.php:

<form action="<?= $actionUrl; ?>" method="POST">

Preparing the controller

To prepare the controller we are first going to create a loadEdit method in the News controller that will validate the news ID and set the required data to the model as a where predicate:

public function loadEdit(Params $parameters, \App\View\CreateNews $newsView)
{
    $params = $parameters->get("parameters");
    if (isset($params[0]) === false || is_numeric($params[0]) === false) {
        $newsView->viewData["error"] = "News ID not defined or not a valid ID";
        return;
    }

    $this->newsModel->where("id", (int)$params[0]);
    $newsView->viewData["actionUrl"] = "/news/{$params[0]}/edit";
}

Saving updated news article

Now that we have loaded the news article into the view for editing, we need to save the changes into the database. To do so, we will require a Controller method, that will save the news with the help of the News Model:

public function edit(
    \SlaxWeb\Router\Request $request,
    \SlaxWeb\Router\Response $response,
    \App\View\CreateNews $view
): bool {
    $id = $request->query->get("parameters");
    if (isset($id[0]) === false || is_numeric($id[0]) === false) {
        $newsView->viewData["error"] = "News ID not defined or not a valid ID";
        return false;
    }
    if (is_empty($title) || is_empty($body)) {
        $view->viewData["error"] = "News article data is not valid.";
        return false;
    }
    if ($this->newsModel->where("id", $id[0])->update($request->request->all())) {
        $view->viewData["error"] = "Error saving edited news article: " . $this->newsModel->lastError();
        return false;
    }
    $response = $response->redirect("/news/{$id}");
    return true;
}

And there we go, we can now successfully edit a news article and save it to the database.

This concludes this simple guide, and the code and methods that you have seen here are certainly not the only way, nor the best way to go about writing applications, it is only meant as a guide to introduce you to the SlaxWeb Framework. There are still a lot of things to explore. We suggest you head to ref:components part of the documentation to explore further.