检查是否使用Laravel数据透视表设置了某些内容

Question

I have a Laravel database with a table for tags, a table for items and a table for item_tag. The tags are hierarchical, and as a result, I'm trying to query which tags have been set inside a loop.

That's easy, I just use $item->tags and it gives me my tags in an accessible object, ready to loop through.

The problem appears when I want to check if a specific object is set, when showing a list of all tags. I'm using the following code for testing:

function buildTree($tags, $selected = null) {
    echo "<ul>";
        foreach($tags as $tag) {
            echo "<li>";
                if($selected[$tag->id]) {
                    echo "<strong>";
                }
                echo $tag->name;
                if($selected[$tag->id]) {
                    echo "</strong>";
                }
                if($tag->children) {
                    buildTree($tag->children);
                }
            echo "</li>";
        }
    echo "</ul>";
}
$item = Item::find(1);
$tags = Tag::whereNull('tag_id')->get();
buildTree($tags, $item->tags);

The expected output would be that each tag that is selected would come up as bold in the tree. Of course, if that had happened, I wouldn't be posting this. Instead, it just highlights the first item in the tree, even though it isn't selected. (That's because $selected isn't supposed to be addressed that way).

What's the correct way to get this information?

Answer 1

That's because $selected isn't supposed to be addressed that way

Then how's it got to be addressed? Of course the answer lies there itself, since you rely on $selected for checking what tags were selected.

As per your comment, the following should solve your problem

Change your if condition from this -

if($selected[$tag->id])

To This -

if(array_in($tag->id, $selected))