PHP 8.1 compatibility / createElement Deprecated Warning

[ghohmann]

Hi,

the current code base throws a PHP warrning if ?verb=ListMetadataFormats is called:
Deprecated: DOMDocument::createElement(): Passing null to parameter #2 ($value) of type string is deprecated in ./Classes/Response.php on line 64.

The is caused by the function public function addChild() which tries to create an element with an empty string as value. In my understanding this triggers a warning since PHP 8.1.

To create an empty element you can simply omit the value. Quick workaround (Response.php from line 63):

public function addChild($mom_node, $name, $value = '') {
        if (!empty($value)) {
                $added_node = $this->doc->createElement($name, $value);
        } else {
                $added_node = $this->doc->createElement($name);
        }
        $added_node = $mom_node->appendChild($added_node);
        return $added_node;
}

There might be a nicer fix to this, though.

[sebastian-meyer]

Thank you for pointing this out! I haven't been working with the Simple OAI-PMH Data Provider for a while now, since there is a successor which supersedes this one in most cases.

But nevertheless I tried to fix all deprecation warnings in #15. Would you like to test this before I merge the changes and release a new version?

[ghohmann]

Thx!

Thank you for pointing this out! I haven't been working with the Simple OAI-PMH Data Provider for a while now, since there is a successor which supersedes this one in most cases.

I already noted the other version of this provider, but wasn't sure if it is activly developed (since there is no readme).
If this is meant to be an successor I think it would be great if it would support both repository options (plain files and database).

But nevertheless I tried to fix all deprecation warnings in #15. Would you like to test this before I merge the changes and release a new version?

Yes. I guess I can test it tomorrow and give you feedback.

[ghohmann]

Hm, there is a problem with ListRecords&metadataPrefix.

There are no results when using
https://<myOAIserver>/?verb=ListRecords&metadataPrefix=oai_dc
in the default installation.
<error code="noRecordsMatch">The combination of the values of the from, until, set and metadataPrefix arguments results in an empty list.</error>

The given example.xml is set in the files array in line 39 of index.php. It seems to be a problem with how $until is set in line 91. In the case of example.com, $until is not null and of same value as $from. Therefore the expression in line 95 is always FALSE.

[sebastian-meyer]

Thanks for checking! I think I found the problem and updated the pull request. That should (hopefully) fix it.

[ghohmann]

Tested it this morning, works like a charm! And all "deprecated" warnings are gone.
Time to merge! :-)

[sebastian-meyer]

Time to merge! :-)

I merged the changes and made a new release: v1.8