As my CakePHP 2.4 app gets bigger, I'm noticing I'm passing a lot of arrays around in the model layer. Cake has kinda led me down this path because it returns arrays, not objects, from it's find calls. But more and more, it feels like terrible practice.
For example, in my Job model, I've got a method like this:
public function durationInSeconds($job) {
return $job['Job']['estimated_hours'] * 3600; // convert to seconds
}
Where as I imagine that using active record patter, it should look more like this:
public function durationInSeconds() {
return $this->data['Job']['estimated_hours'] * 3600; // convert to seconds
}
(ie, take no parameter, and assume the current instance represents the Job you want to work with)
Is that second way better?
And if so, how do I use it when, for example, I'm looping through the results of a find('all') call? Cake returns an array - do I loop through that array and do a read for every single row? (seems a waste to re-fetch the info from the database)
Or should I implement a kind of setActiveRecord method that emulates read, like this:
function setActiveRecord($row){
$this->id = $row['Job']['id'];
$this->dtaa = $row;
}
Or is there a better way?
EDIT: The durationInSeconds method was just a simplest possible example. I know for that particular case, I could use virtual fields. But in other cases I've got methods that are somewhat complex, where virtual fields won't do.
The best solution depends on the issue you need to solve. But if you have to make a call to a function for each result row, perhaps it is necessary to redesign the query taking all the necessary data.
In this case that you have shown, you can use simply a virtual Field on Job model:
$this->virtualFields = array(
'duration_in_seconds' => 'Job.estimated_hours * 3600',
):
..and/or you can use a method like this:
public function durationInSeconds($id = null) {
if (!empty($id)) {
$this->id = $id;
}
return $this->field('estimated_hours') * 3600; // convert to seconds
}
Related
Sometimes we have to perform same DB operation multiple times within a loop. How can I compute the execution time for each operation using JMH?
public void applyAll(ArrayList<parameter_type> lists) {
for(parameter_type param : lists) {
saveToDB(param);
}
}
How can I compute the execution time for saveToDB(param) for each time it is being executed/called?
DB operations are really nothing to microbenchmark. Their will depend on multiple things that are quite impossible to isolate.
As for using parameters, have a look at this answer that explains the use of the #Param annotation.
As #RafaelWinterhalter said, this type of calls are prone to give misleading results in benchmarks. But if you still want to try, then:
Serialize and save a reference list of calls.
Then in a benchmark use a #State(Scope.Thread) object to restore this list to an array and have a loop counter variable there.
Then #Benchmark public int test1_saveToDB(MyState state) { saveToDB(state.params[state.i]); return state.i++; }
Is there a way to cache virtual fields? I mean automatically, with the entity to which they belong, because I understand that, even if an entity is retrieved from the cache, virtual fields are generated whenever it is necessary.
Obviously I know I can take care of it personally, so (example):
protected function _getFullName()
{
$fullName = Cache::read('full_name_for_' . $this->_properties['id'], 'users');
if (empty($fullName)) {
$fullName = $this->_properties['first_name'] . ' ' . $this->_properties['last_name'];
Cache::write('full_name_for_' . $this->_properties['id'], $fullName, 'users');
}
return $fullName;
}
But I wanted to know if in fact CakePHP can do it directly.
EDIT
Context.
The Post entity has the text property. text can contain images (as html code), even remote. Now I have to store somewhere the url of the first image contained in the text and its size. So I have created the first_image virtual field, that uses a regex. The problem is rather with the image size: I can not do run every time the getimagesize() function, especially if the image is remote, for reasons that you can easily understand. So how to do?
Is there a way to cache virtual fields?
No.
And what you do doesn't make much sense. The caching is for sure causing more overhead than that you gain anything from it in this case.
Use concat() on the DB level to concatenate the name instead.
Also if there would be a real need to cache a virtual property, then I would say there went something clearly wrong in the architecture.
It makes sense to me to want to prevent code in accessors/virtual fields from being executed more than once on the same request, which can easily happen if you use them several places in your script.
You can do a solution like this, but I'm not entirely sure how kosher it is:
private $fullName_cache = false;
protected function _getFullName()
{
if(!$this->fullName_cache){
$fullName = Cache::read('full_name_for_' . $this->_properties['id'], 'users');
if (empty($fullName)) {
$fullName = $this->_properties['first_name'] . ' ' . $this->_properties['last_name'];
Cache::write('full_name_for_' . $this->_properties['id'], $fullName, 'users');
}
$this->fullName_cache = $fullName;
}
return $this->fullName_cache;
}
I think there might be a nicer way to do this. There is mention of this sort of thing in the cookbook:
Code in your accessors is executed each time you reference the field. You can use a local variable to cache it if you are performing a resource-intensive operation in your accessor like this: $myEntityProp = $entity->my_property.
Anyone had luck implementing this?
http://example.com/api/transfer/transfers/code/456/code/234
When using $this->get('code') on a url like above I expect the REST library to return an array or a list of the codes.
Instead it returns the last one.
Is there a way to return both values in a list, or is there another recommandation for formating the URL.
Thank you
I know it has been long since you posted the question. However it could help other people looking for the same thing.
Assuming that transfer is your controller and transfers is the function, another way to format your url could be:
http://example.com/api/transfer/transfers?code[]=456&code[]=234
This was you perform $this->get('code') you'll get an array back.
If you are creating the url via code then you may use http_build_query(). It handles the necessary escaping. It means it will replace [ for %5B and ] for %5D, in this case.
The code would be like:
$codes = array(456, 234);
$query = http_build_query(array('code' => $data));
$url = 'http://example.com/api/transfer/transfers?' . $query;
What function is equal to mysql_num_rows in Magento?
For Magento, the proper equivalent is PHP's count() function.
Why?
Magento usually uses Varien_Data_Collection instances to fetch result sets containing multiple records. Varien implements the Lazy Load Pattern for these collections, that is, no result set will be fetched before you really need it.
If you take a look at the Varien_Data_Collection class, you'll see, that this class does implement PHP's Countable interface and the proper count() method for this interface:
class Varien_Data_Collection implements IteratorAggregate, Countable
{
:
public function count()
{
$this->load();
return count($this->_items);
}
:
}
If you're asking yourself now, what got lazy loading to do with counting records, then you need to know that querying a collection the usual Magento way, e.g. like this:
$collection = Mage::getModel('catalog/product')
->getCollection()
->addFieldToFilter(
'status',
Mage_Catalog_Model_Product_Status::STATUS_ENABLED
);
does not fetch the result set at all. But, how do you count records of a result set which hasn't been fetched yet? Right, you can't. And neither can mysql_num_rows. It fetches the result set first.
Now, when you call count() on the collection, e.g. by
$n = count($collection);
PHP's core count() function will detect that the passed argument $collection implements a Countable interface and has its own count() method defined, so it will call that one.
This leads to really fetching the result set* and storing it to $this->_items, which finally allows counting the records and return the number.
* In Magento you can also call foreach ($collection as $product) to really fetch the result set, but that's another story.
I'm calling a stored proc in a foreach loop and would like to change the value of one of the parameters on each iteration. Currently, there doesn't seem to be any way to access the parameters once they've been added to DynamicParameters although from reading the source, I can see that DynamicParameters does keep an internal Dictionary. Any reason why this isn't public or if there's another way to get at the ParamInfos to change values?
Update
What I have currently:
foreach ( var fooID in fooIDs )
{
var dynamicParameters = new DynamicParameters();
dynamicParameters.Add( ParameterNames.BarID, barID );
dynamicParameters.Add( ParameterNames.FooID, fooID);
connection.Execute( ProcNames.MyProc, dynamicParameters, commandType:CommandType.StoredProcedure );
}
Re-Add the parameter.
// Call Add() with new values.
dynamicParameters.Add(ParameterNames.BarID, differentBarID);
There is no real reason DynamicParameters is so secret about what it does, the ParamInfo class could be exposed and I would be happy to provide proper iteration/modification properties and/or methods. If you feel like you would like to pitch in, please submit a patch.
In the mean time you can simply implement IDynamicParameters which is the trivial interface we use to dispatch this to the underlying command, in your app. You can use DynamicParameters as a starting point.