How to get a value of a topic (array)

Developing with Concrete
1

hi all

i am trying to get one single value of an array, if i day print_r it says:

Array
(
    [0] => Concrete\Core\Tree\Node\Type\Topic Object
        (
            [childNodes:protected] => Array
                (
                )

            [childNodesLoaded:protected] => 
            [treeNodeIsSelected:protected] => 
            [tree:protected] => Concrete\Core\Tree\Type\Topic Object
                (
                    [treeNodeSelectedIDs:protected] => Array
                        (
                        )

                    [error] => 
                    [treeID] => 5
                    [treeTypeID] => 3
                    [treeDateAdded] => 2022-12-08 17:58:47
                    [rootTreeNodeID] => 30
                    [topicTreeName] => News Filter
                )

            [error] => 
            [treeNodeID] => 34
            [treeNodeTypeID] => 7
            [treeID] => 5
            [treeNodeParentID] => 30
            [treeNodeDisplayOrder] => 0
            [treeNodeName] => News
            [dateModified] => 2022-12-08 18:07:46
            [dateCreated] => 2022-12-08 18:07:46
            [treeNodeOverridePermissions] => 0
            [inheritPermissionsFromTreeNodeID] => 30
            [treeNodeTypeHandle] => topic
        )

)

if i try something like:

            <?php
            $array = $page->getAttribute('category');
            print_r($array);
            echo $array[10];
            ?>

to test it only says either nothing, NULL or “Array”.
But I would like to have the value of “treeNodeName”.

thank you for your inputs!

2

you can’t do that
maybe this piece of code may help you

function lesDisciplines($ladiscipline){
  $topicTree = TopicTree::getByName('Disciplines');
  $topicsRoot = TreeNode::getByID($topicTree->getRootTreeNodeObject()->treeNodeID);
  $topicsRoot->populateChildren();
  $csnTopics = $topicsRoot->getChildNodes();
      foreach ($csnTopics as $discipline) {
                                        echo '<option value="' . $discipline->treeNodeID . '"';
          if($discipline->treeNodeID==$_GET['discipline']){
              echo " selected";
          }
          echo '>'. $discipline->treeNodeName .'</option>';
                                }
}
1 Like
3

Your exemple array only has 1 element the one with key value of 0 so if you try to get an element with key equal to 10 you won’t get anything.

Now in the example you gave $array[0] is an object of type Concrete\Core\Tree\Node\Type\Topic so you can’t really do print_r on an object.

What you could do is

$topic = $array[0]; // getting the first element in the array, the one with index 0
// now $topic is an object of type Concrete\Core\Tree\Node\Type\Topic so you can use its public methods. Example:
echo $topic->getTreeNodeDisplayName();
echo $topic->getDateLastModified();
4

Super star!!! :slight_smile: thank you so much!

5

dear mnakalay
just one more question which came up – if a do not choose a certain page type (see attachment), it endsup in an error ( “Call to a member function getTreeNodeDisplayName() on null”).
so it only works with this page type. what if the client changes it accidentally?

6

I think you forgot the attachment you’re referring to so I’m not sure what the issue is.

7

i am so sorry, can you see it now?

Bildschirm­foto 2023-03-17 um 14.36.19
Bildschirm­foto 2023-03-17 um 14.36.19736×400 27 KB

8

and this happens if you create a new page and no topic is selected. if you publish the site immediately that’s not possible because topics are a must field. if you plan the site online time, you can “avoid” the must fields.

Bildschirm­foto 2023-03-18 um 16.58.33
Bildschirm­foto 2023-03-18 um 16.58.331130×383 40.1 KB

9

This is because you are asking to echo out the topic but it’s not there so crashes.

What I would do is isset() the topic

10

thank you very much!
but just one question, i also need then to echo something? i am confused… :face_with_peeking_eye:

11

Where you have you line with the <p class="page-list-category… Etc

Wrap the whole thing with

<?php

if isset($topic){ 

?>

<p .....


<?php } ?>

So what you are saying is that if $topic actually has something, produce the code.

12

thank you very much for this!
that helps, do you mind giving me a hint, how it needs to be if i have an if condition already?

if ($topic->getTreeNodeDisplayName() == "Monthly Report" && $downloadLink != 0) { ?>
<?php echo $textNewsDE ?>
<a class="btn secondary-blue-btn" href="<?php echo $downloadLink->getDownloadURL(); ?>" target="_blank">Download PDF</a>
<?php }

i somehow dont get it, what needs to be done, if no topic is delivered. can it be filled with a standard topic? i just want to avoid these failure screens…

13

Isset might not work here. Better check tht you have an object. Like this :

if (is_object($topic) && $topic->getTreeNodeDisplayName() == "Monthly Report" && $downloadLink != 0) { ?>
<?php echo $textNewsDE ?>
<a class="btn secondary-blue-btn" href="<?php echo $downloadLink->getDownloadURL(); ?>" target="_blank">Download PDF</a>
<?php }
14

thank you so much !
but do i need an else value?
sorry i am completely lost :face_with_peeking_eye:

15

Not really. If you have a topic and it is “monthly Report” and you have a download link, you will show a link to your file.

Otherwise you won’t show anything.

By the way you should probably modify the code to also check $downloadLink correctly. Like this

if (is_object($topic) && $topic->getTreeNodeDisplayName() == "Monthly Report" && is_object($downloadLink)) { ?>
<?php echo $textNewsDE ?>
<a class="btn secondary-blue-btn" href="<?php echo $downloadLink->getDownloadURL(); ?>" target="_blank">Download PDF</a>
<?php }