How do you check within the view template if the result object contains any entries?
(There was a similar question already, but this one is slightly different)
Take the CakePHP 3 blog tutorial for example. They show how to list all articles on one page:
// src/Controller/ArticlesController.php
public function index() {
$this->set('articles', $this->Articles->find('all'));
}
And the view template:
<!-- File: src/Template/Articles/index.ctp -->
<table>
<tr>
<th>Id</th>
<th>Title</th>
</tr>
<?php foreach ($articles as $article): ?>
<tr>
<td><?= $article->id ?></td>
<td>
<?= $this->Html->link($article->title, ['action' => 'view', $article->id]) ?>
</td>
</tr>
<?php endforeach; ?>
</table>
Disadvantage: if there are no entries in the database the HTML table is still rendered.
How can I prevent this and show a simple message like "Sorry no results" insteat?
In CakePHP 2
I used
if ( !empty($articles['0']['id']) ) {
// result table and foreach here
} else {
echo '<p>Sorry no results...</p>';
}
But since $articles
is now an object this doesn't work anymore... Is there a new "short way" to check the result object? Or do you usally use another foreach first, like
$there_are_results = false;
foreach ($articles as $article) {
if ( !empty($article->id) ) {
$there_are_results = true;
break;
}
}
if ( $there_are_results == true ) {
// result table and second foreach here
} else {
echo '<p>Sorry no results...</p>';
}
Thanks for your hints.
You can use the iterator_count()
function to know if there are results in the set:
if (iterator_count($articles)) {
....
}
You can also use the collection methods to get the first element:
if (collection($articles)->first()) {
}
Edit:
Since CakePHP 3.0.5 the best way to check for emptiness on a query or a result set is this:
if (!$articles->isEmpty()) {
...
}
I believe you can call $articles->count() from your template. (Check for 0)
Something I have been struggling for a while..
if(!$articles->isEmpty()) {
gives error on empty value
Call to a member function isEmpty() on null
<?php if(iterator_count($articles)) { ?>
Argument 1 passed to iterator_count() must implement interface Traversable, null given
<?php if (collection($articles)->first()) {?>
Only an array or \Traversable is allowed for Collection
I got to work, the problem if you render a different view in the controller $this->render('index'); for a function you should do that after the values has been set
来源:https://stackoverflow.com/questions/30009554/check-if-object-exists-or-is-empty-in-view-template