Created hydrator strategy chain

[ojhaujjwal]

Feedbacks are welcome!

[moderndeveloperllc]

Might want to put [WIP] into the title. I know that the ZF2 folks will want you to have written the tests for this too. I also wonder as to the need for this. You can already add multiple strategies to a hydrator with addStrategy(). Am I missing a use case for this?

[ojhaujjwal]

@moderndeveloperllc
I have added WIP as you said! Thanks!
I will definitely add tests.. And, that`s what WIP means.
And, You cannot add multiple strategies to the same name!

[ojhaujjwal]

@moderndeveloperllc

Use Case:

Support, there is an entity, Event like this:

class Event
{
    protected $time;

   public function setTime(DateTime $time)
   {
        $this->time = $time;
    }

   public function getTime()
    {
        return $this->time;
    }
}

Support a user enters a time in form for that event:

class DateTimeStringStrategy implements StrategyInterface
{
    public function extract($value)
    {
        return $value->format('Y-m-d'); 
    }

    public function hydrate($value)
    {
        return new DateTime($value);
    }
}

class TimeZoneConverterStrategy implements StrategyInterface
{
    public function extract($value)
    {
        $value->setTimezone($serverTimeZone);
        return $value;
    }

    public function hydrate($value)
    {
        $value->setTimezone($clientTimeZone); 
        return $value;
    }
} 

$strategy->attach(new DateTimeStringStrategy(), 10, 5);
$strategy->attach(new TimeZoneConverterStrategy(), 5, 10);
$hydrator->addStrategy('time', $strategy);

[ojhaujjwal]

I think the tests should be enough!

[Ocramius]

Closing brace on its own line.

[ojhaujjwal]

@Ocramius Done.

[localheinz]

Please restart the build.

See #6205 (comment).

[bakura10]

I'm not sure about splitting into extraction strategies and hydration strategies (note: I've back ported your code to my ZF3 refactor). Usually, extraction and hydration are quite symmetrical, what is the use case of splitting into extraction and hydration strategies?

[ojhaujjwal]

@bakura10 If we do not split the strategies to extraction and hydration strategies, then,we need to need to execute strategies in exactly the opposite order during hydration and extraction That will make things simpler.

Suppose , instead of hydrationStrategies as extractionStrategies, we have only strategies.

    public function hydrate($value)
    {
        foreach ($this->strategies as $strategy) {
            $value = $strategy->hydrate($value);
        }

        return $value;
    }

    public function extract($value)
    {
        $strategies = iterator_to_array($this->strategies);
        $strategies = array_reverse($strategies);
        foreach ($strategies as $strategy) {
            $value = $strategy->extract($value);
        }

        return $value;
    }

[bakura10]

I see... What's so bad about the array reverse options? It's indeed much simpler to use to only add one strategy instead of two, and letting the strategy handle the ordering.

Envoyé de mon iPhone

Le 19 mai 2014 à 04:31, Ujjwal Ojha [email protected] a écrit :

@bakura10 If we do not split the strategies to extraction and hydration strategies, then,we need to need to execute strategies in exactly the opposite order during hydration and extraction That will make things simpler.

Suppose , instead of hydrationStrategies as extractionStrategies, we have only strategies.

public function hydrate($value)
{
    foreach ($this->strategies as $strategy) {
        $value = $strategy->hydrate($value);
    }

    return $value;
}

public function extract($value)
{
    $strategies = iterator_to_array($this->strategies);
    $strategies = array_reverse($strategies);
    foreach ($strategies as $strategy) {
        $value = $strategy->extract($value);
    }

    return $value;
}

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[ojhaujjwal]

There is nothing bad about the array reverse. That idea came to mind recently and I wanted your feedback. So, I will do it that way.

[ojhaujjwal]

@bakura10 What do you think now?

[Ocramius]

What if $value['name'] does not exist? Seems fragile to me...

[adamlundrigan]

@ojhaujjwal what is the status of this? Is there a matching documentation PR for this new feature?

[ojhaujjwal]

@adamlundrigan Okay, I will create a documentation PR soon. Thanks for reminding.

[Ocramius]

a default priority of 1 would match the default priority of all other components using events/queues, no?

[ojhaujjwal]

I agree. Will change!

[samsonasik]

2015 ;)

[ojhaujjwal]

I have made this class final and removed unnecessary setters/getters!

[Ocramius]

You can probably skip all this and use ArrayUtils::iteratorToArray() instead, which already encapsulates this conditional

[ojhaujjwal]

Okay. I have removed priorities support!

[weierophinney]

Merged to develop for release with 2.4.0.

@ojhaujjwal Please write up some documentation for the https://github.com/zendframework/zf2-documentation repository! :)