When using a closure in the "route_params" config section the metadata_map in zf-hal the config isn't re-rendered correctly when making changes

[benwaine]

I needed to add a route parameter to a nested collection. I'm using doctrine so the objects returned from my controllers are entities. Entities have a reference to their parents so can be used to find the correct url parameters.

Eg - To obtain the the url: /list/:list_id/items[/:item_id]

I used the following zf-hal config:

    'zf-hal' => array(
        'metadata_map' => array(
            'List\\List\\List' => array(
                'entity_identifier_name' => 'id',
                'route_name' => 'lists.rest.list',
                'route_identifier_name' => 'list_id',
                'hydrator' => 'List\\List\\ListHydrator',
            ),
            'List\\List\\ListCollection' => array(
                'entity_identifier_name' => 'id',
                'route_name' => 'lists.rest.list',
                'route_identifier_name' => 'list_id',
                'is_collection' => true,
            ),
            'Lists\\V1\\Rest\\ListItem\\ListItemEntity' => array(
                'entity_identifier_name' => 'id',
                'route_name' => 'lists.rest.list-item',
                'route_identifier_name' => 'list_item_id',
                'hydrator' => 'Zend\\Stdlib\\Hydrator\\ArraySerializable',
            ),
            'Lists\\V1\\Rest\\ListItem\\ListItemCollection' => array(
                'entity_identifier_name' => 'id',
                'route_name' => 'lists.rest.list-item',
                'route_identifier_name' => 'list_item_id',
                'is_collection' => true,
            ),
            'List\\List\\ListItem' => array(
                'entity_identifier_name' => 'id',
                'route_name' => 'lists.rest.list-item',
                'route_identifier_name' => 'list_item_id',
                'hydrator' => 'Zend\\Stdlib\\Hydrator\\ArraySerializable',
                'route_params' => array(
                    'list_id' => function($obj) {
                        return $obj->getList()->getId();
                }
                ),
            ),
            ),
        ),
    )

When I make any change to any endpoint and the content is re-rendered:

    'zf-hal' => array(
        'metadata_map' => array(
            'List\\List\\List' => array(
                'entity_identifier_name' => 'id',
                'route_name' => 'lists.rest.list',
                'route_identifier_name' => 'list_id',
                'hydrator' => 'List\\List\\ListHydrator',
            ),
            'List\\List\\ListCollection' => array(
                'entity_identifier_name' => 'id',
                'route_name' => 'lists.rest.list',
                'route_identifier_name' => 'list_id',
                'is_collection' => true,
            ),
            'Lists\\V1\\Rest\\ListItem\\ListItemEntity' => array(
                'entity_identifier_name' => 'id',
                'route_name' => 'lists.rest.list-item',
                'route_identifier_name' => 'list_item_id',
                'hydrator' => 'Zend\\Stdlib\\Hydrator\\ArraySerializable',
            ),
            'Lists\\V1\\Rest\\ListItem\\ListItemCollection' => array(
                'entity_identifier_name' => 'id',
                'route_name' => 'lists.rest.list-item',
                'route_identifier_name' => 'list_item_id',
                'is_collection' => true,
            ),
            'List\\List\\ListItem' => array(
                'entity_identifier_name' => 'id',
                'route_name' => 'lists.rest.list-item',
                'route_identifier_name' => 'list_item_id',
                'hydrator' => 'Zend\\Stdlib\\Hydrator\\ArraySerializable',
                'route_params' => array(
                    'list_id' => Closure::__set_state(array(
                )),
                ),
            ),
            ),
        ),
    )

The following error is output:

Fatal error: Call to undefined method Closure::__set_state() in /vagrant/src/module/Lists/config/module.config.php on line 188 Call Stack: 0.0009 246960 1. {main}() /vagrant/src/public/index.php:0 0.0404 745696 2. Zend\Mvc\Application::init() /vagrant/src/public/index.php:51 0.1079 1902896 3. Zend\ModuleManager\ModuleManager->loadModules() /vagrant/src/vendor/zendframework/zendframework/library/Zend/Mvc/Application.php:252 0.1079 1903280 4. Zend\EventManager\EventManager->trigger() /vagrant/src/vendor/zendframework/zendframework/library/Zend/ModuleManager/ModuleManager.php:115 0.1080 1903840 5. Zend\EventManager\EventManager->triggerListeners() /vagrant/src/vendor/zendframework/zendframework/library/Zend/EventManager/EventManager.php:207 0.1091 1926376 6. call_user_func() /vagrant/src/vendor/zendframework/zendframework/library/Zend/EventManager/EventManager.php:468 0.1091 1926544 7. Zend\ModuleManager\ModuleManager->onLoadModules() /vagrant/src/vendor/zendframework/zendframework/library/Zend/EventManager/EventManager.php:468 0.1186 2044184 8. Zend\ModuleManager\ModuleManager->loadModule() /vagrant/src/vendor/zendframework/zendframework/library/Zend/ModuleManager/ModuleManager.php:96 0.1225 2058304 9. Zend\EventManager\EventManager->trigger() /vagrant/src/vendor/zendframework/zendframework/library/Zend/ModuleManager/ModuleManager.php:174 0.1226 2058344 10. Zend\EventManager\EventManager->triggerListeners() /vagrant/src/vendor/zendframework/zendframework/library/Zend/EventManager/EventManager.php:207 0.1231 2067064 11. call_user_func() /vagrant/src/vendor/zendframework/zendframework/library/Zend/EventManager/EventManager.php:468 0.1231 2067096 12. Zend\ModuleManager\Listener\ConfigListener->onLoadModule() /vagrant/src/vendor/zendframework/zendframework/library/Zend/EventManager/EventManager.php:468 0.1231 2067096 13. Lists\Module->getConfig() /vagrant/src/vendor/zendframework/zendframework/library/Zend/ModuleManager/Listener/ConfigListener.php:126 0.1246 2093928 14. include('/vagrant/src/module/Lists/config/module.config.php') /vagrant/src/module/Lists/src/Lists/Module.php:17

PHP Version:

vagrant@vagrant-ubuntu-trusty-64:/vagrant/src/tests/behavioural$ php -v
PHP 5.5.9-1ubuntu4.7 (cli) (built: Mar 16 2015 20:47:39) 
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2014 Zend Technologies
    with Zend OPcache v7.0.3, Copyright (c) 1999-2014, by Zend Technologies
    with Xdebug v2.2.3, Copyright (c) 2002-2013, by Derick Rethans

Modules:

vagrant@vagrant-ubuntu-trusty-64:/vagrant/src/tests/behavioural$ php -m
[PHP Modules]
bcmath
bz2
calendar
Core
ctype
curl
date
dba
dom
ereg
exif
fileinfo
filter
ftp
gettext
hash
iconv
intl
json
libxml
mbstring
mhash
mysql
mysqli
openssl
pcntl
pcre
PDO
pdo_mysql
Phar
posix
readline
Reflection
session
shmop
SimpleXML
soap
sockets
SPL
standard
sysvmsg
sysvsem
sysvshm
tokenizer
wddx
xdebug
xml
xmlreader
xmlwriter
Zend OPcache
zip
zlib

[Zend Modules]
Xdebug
Zend OPcache

Any one have an idea what could be going on?

[benwaine]

Additional info from composer.lock

            "name": "zfcampus/zf-apigility",
            "version": "1.0.2",
            "source": {
                "type": "git",
                "url": "https://github.com/zfcampus/zf-apigility.git",
                "reference": "1bd864875d1b23e3db4923849f0c2e16fd820538"
            }

            "name": "zfcampus/zf-hal",
            "version": "1.0.4",
            "source": {
                "type": "git",
                "url": "https://github.com/zfcampus/zf-hal.git",
                "reference": "7f64cd827c1b0c11a7d92789840b996e4f7cbcf3"
            },

[weierophinney]

This is why we do not recommend using closures in configuration, particularly with Apigility; the UI is serializing and writing to those files directly!

To be honest, I'm surprised you can use a closure there at all, and am trying to determine how that works; I don't see anywhere where we call the closure to get the value anywhere in zf-hal or ZF2!

Until I can figure that out, one possible way to make this work is to modify the value during configuration merging.

[benwaine]

Here is where it happens in ZF-Hal:

https://github.com/zfcampus/zf-hal/blob/master/src/Plugin/Hal.php#L1329

I found it when looking through the tests:

https://github.com/zfcampus/zf-hal/blob/master/test/Plugin/HalTest.php#L844

What's the recommended approach to generate links from a complex object if not using closures?

Thanks

Ben

[benwaine]

Digging into this a little more:

In ZF-Hal metadata map route_parameters are used when creating the 'self' link. These route parameters can be closures. However where links are specified in the metadata map and a route name and params are specified, closures may not be used in the params.

This is due to the behaviour of Hal::marshalSelfLinkFromMetadata (called when creating the self link) vs Hal::marshalMetadataLinks the former calls any closures passed as route_parameters where the later does not.

When an entity with an embedded link (not self) hits the Hal::renderEntity method any parameters which are closures have not had their values swapped for the result of calling the closure.

Would you accept a pull request to fix this behaviour?

[Wilt]

I would also like support for rendering closures for other links then self links.
I also made a pull request for generalizing the rendering of links from metadata other then self links. This has been merged already in the develop branch. With the $relation param you can now render links other then self links with this method...

To solve my rendering of closures in the metadata correctly I now I made a RenderLinksListener that does this resolving of the route parameters for me. This listener has a method resolveRouteParams like this:

    /**
     * @param $entity
     * @param LinkCollection $halLinks
     */
    public function resolveRouteParams($entity, LinkCollection &$halLinks)
    {
        /** @var Link $link */
        foreach($halLinks as $link)
        {
            $params = $link->getRouteParams();

            // process any callbacks
            foreach ($params as $key => $param) {
                // bind to the object if supported
                if ($param instanceof Closure
                    && version_compare(PHP_VERSION, '5.4.0') >= 0
                ) {
                    $param = $param->bindTo($entity);
                }

                // pass the object for callbacks and non-bound closures
                if (is_callable($param)) {
                    $params[$key] = call_user_func_array($param, array($entity));
                    if($params[$key] === false || $params[$key] === null){
                        $relation = $link->getRelation();
                        $halLinks->remove($relation);
                    }
                }
            }

            $link->setRouteParams($params);
        }
    }

Maybe this could be a (temporary) solution for @benwaine too...

[benwaine]

@Wilt Thanks - I'll take a look at this when I'm back in the office on Monday. Looks like what I need.

[benwaine]

@Wilt - fixed my problem. Look forward to using your real fix in the next point release!

[Wilt]

Good to hear it worked for you. Not so sure about this real fix you are mentioning. I think you misinterpreted me, no real fix there yet...