How do I add a global variable to working memory in drools planner's solver to be able to use in scores drool. This is similar to https://issues.jboss.org/browse/JBRULES-2700 but couldn't find a solution though.
What you might be looking for is a #ProblemFactProperty.
Quoting from the documentation:
All objects returned by those [annotated] methods will be inserted into the
ConstraintStreams or Drools session, so the constraint steams or score
rules can access them.
In my own words: You can hold a reference to your global object in your #PlanningSolution class. If you annotate its getter with #ProblemFactProperty you can access it from your drools file.
First some preaching: Using a service (set as a global) to calculate part of the score will break delta based score calculation (read the manual section on that topic), resulting in much less score calculations per second (say 50 instead of 5000 per second on big data sets).
Then a HACK solution: In the StartingSolutionInitializer (soon known as CustomSolverPhaseCommand) do solverScope.getWorkingMemory().setGlobal("key", value).
Then a real, long-term solution: Could you motivate why you need to be able to do this? We can think about adding support for this with something like an optional WorkingMemoryPreperator.
After set the planningProblem:
solver.setPlanningProblem(planningProblem);
You can get access the workingMemory via solutionDirector(HACK) :
DefaultSolutionDirector solutionDirector = ((DefaultSolver)solver).getSolverScope().getSolutionDirector();
solutionDirector.getWorkingMemory().setGlobal("list", new ArrayList<String>());
Cheers!
If you need to use some helper methods in the planner rules, try the following approach which I used in my project:
Create a utility class which includes the helper methods.
Import the utility class in the rule file like importing it in a java class.
Use the helper method in the rule. If you want to use a helper method in the condition, wrap using eval(). If you want to use a helper method in the then part, just use it as normal java method call.
For example, say you have a utility class named PlanningUtil like below:
public class PlanningUtil {
public boolean isGood() {return true;}
public void doSomething() {//...}
}
Then import the utility class in the rule file,
import PlanningUtil;
Use the utility method in the rule
rule "MyRule"
when
eval(PlanningUtil.isGood())
then
PlanningUtil.doSomething(); // note the ';' is a must.
end
Related
My code use apache.ml.clustering.GaussianMixture, but its init method private def initRandom(...) does not work well, so I want to customize a new init method.
At first I want to "extends" class GuassianMixture, but initRandom is a private method.
Then I tried another way, it is to set initial GMM, but sadly source code says that TODO: SPARK-15785 Support users supplied initial GMM.
I've also tried to copy the code of class GuassianMixture for my custom class, but there are too many things attached to it. GaussianMixture.scala comes with sort of classes and traits, some of which are only accessible within ML packages.
I solved it by myself. Here is my solution.
I created class CustomGaussianMixture which extends GaussianMixture from official package org.apache.spark.ml.clustering.
And within my project, I created a new package, also named as org.apache.spark.ml.clustering(to prevent deal with scope of sort of complexity classes/traits/objects in org.apache.spark.ml.clustering). And place my custom class in it.
The next thing is to override the method(fit) call initRandom, a non-private method, so I can override it. Specifically, Just write my new init method in class CustomGaussianMixture, and copy method fit from official source code in GaussianMixture.scala to class CustomGaussianMixture, remember to modify code in CustomGaussianMixture.fit() to call my custom init method.
At last, just use CustomGaussianMixture instead of GaussianMixture when needed.
As the topic, when I use ortools, I want to serialize cpsolver, CpSolverSolutionCallback and cpmodel to achieve multithread computing. However, I can't just serialize those objects directly and I think I need to only serialize their configuration and reset configuration in each thread, such as all the constraint and variables in the cpmodel and parameters in cpsolver. This is the question, how can I get all those values using ortools? Is there an api or something? I can't find it when searching on Google.
Every language implements a thin wrapper above a protocol buffer file.
This file is described here
This model is accessible from each CpModel class.
Now you can distribute work using this proto directly. You will need to look at the CpSolver class to understand how the c++ Solve method is called.
See the python solve method.
The way to implement your request.
Create your model normally.
Extract the underlying protocol buffer model underneath and use it for parallelism/distribution.
Solve will returns a CpSolverResponse object. To get the value of a variable in the response, call response.Value(var.Index()), or store the index of the relevant variables and use it in the Value() method call.
I'm looking for a way of condensing some of my AS3 code to avoid almost duplicate commands.
The issue is that I have multiple variables with almost the same name e.g. frenchLanguage, englishLanguage, germanLanguage, spanishLanguage
My Controller class contains public static variables (these are accessed across multiple classes) and I need a way to be able to call a few of these variables dynamically. If the variables are in the class you are calling them from you can do this to access them dynamically:
this["spanish"+"Language"]
In AS3 it's not possible to write something like:
Controller.this["spanish"+"Language"]
Is there any way to achieve this? Although everything is working I want to be able to keep my code as minimal as possible.
It is possible to access public static properties of a class this way (assuming the class name is Controller as in your example:
Controller['propertyName']
I'm not sure how this helps to have "minimal code", but this would be a different topic/question, which might need some more details on what you want to achive.
Having said that, I like the approach DodgerThud suggests in the comments of grouping similar values in a (dynamic) Object or Dictonary and give it a proper name.
Keep in mind, that if the string you pass in as the key to the class or dynamic object is created from (textual) user input you should have some checks for the validity of that data, otherwise your programm might crash or expose other fields to the user.
It would make sense to utilize a Dictionary object for a set of variables inherited: it provides a solid logic and it happens to work...
I do not think this is what you are trying to accomplish. I may be wrong.
Classes in AS3 are always wrapped within a package - this is true whether you have compiled from Flash, Flex, Air, or any other...
Don't let Adobe confuse you. This was only done in AS3 to use Java-Based conventions. Regardless, a loosely typed language is often misunderstood, unfortunately. So:
this["SuperObject"]["SubObject"]["ObjectsMethod"][ObjectsMethodsVariable"](args..);
... is technically reliable because the compiler avoids dot notation but at runtime it will collect a lot of unnecessary data to maintain those types of calls.
If efficiency becomes an issue..
Use:
package packages {
import flash.*.*:
class This implements ISpecialInterface {
// Data Objects and Function Model
// for This Class
}
package packages {
import...
class ISpecialInterface extends IEventDispatcher
Say I have a class that looks like the following:
internal class SomeClass
{
IDependency _someDependency;
...
internal string SomeFunctionality_MakesUseofIDependency()
{
...
}
}
And then I want to add functionality that is related but makes use of a different dependency to achieve its purpose. Perhaps something like the following:
internal class SomeClass
{
IDependency _someDependency;
IDependency2 _someDependency2;
...
internal string SomeFunctionality_MakesUseofIDependency()
{
...
}
internal string OtherFunctionality_MakesUseOfIDependency2()
{
...
}
}
When I write unit tests for this new functionality (or update the unit tests that I have for the existing functionality), I find myself creating a new instance of SomeClass (the SUT) whilst passing in null for the dependency that I don't need for the particular bit of functionality that I'm looking to test.
This seems like a bad smell to me but the very reason why I find myself going down this path is because I found myself creating new classes for each piece of new functionality that I was introducing. This seemed like a bad thing as well and so I started attempting to group similar functionality together.
My question: should all dependencies of a class be consumed by all its functionality i.e. if different bits of functionality use different dependencies, it is a clue that these should probably live in separate classes?
When every instance method touches every instance variable then the class is maximally cohesive. When no instance method shares an instance variable with any other, the class is minimally cohesive. While it is true that we like cohesion to be high, it's also true that the 80-20 rule applies. Getting that last little increase in cohesion may require a mamoth effort.
In general if you have methods that don't use some variables, it is a smell. But a small odor is not sufficient to completely refactor the class. It's something to be concerned about, and to keep an eye on, but I don't recommend immediate action.
Does SomeClass maintain an internal state, or is it just "assembling" various pieces of functionality? Can you rewrite it that way:
internal class SomeClass
{
...
internal string SomeFunctionality(IDependency _someDependency)
{
...
}
internal string OtherFunctionality(IDependency2 _someDependency2)
{
...
}
}
In this case, you may not break SRP if SomeFunctionality and OtherFunctionality are somehow (functionally) related which is not apparent using placeholders.
And you have the added value of being able to select the dependency to use from the client, not at creation/DI time. Maybe some tests defining use cases for those methods would help clarifying the situation: If you can write a meaningful test case where both methods are called on same object, then you don't break SRP.
As for the Facade pattern, I have seen it too many times gone wild to like it, you know, when you end up with a 50+ methods class... The question is: Why do you need it? For efficiency reasons à la old-timer EJB?
I usually group methods into classes if they use a shared piece of state that can be encapsulated in the class. Having dependencies that aren't used by all methods in a class can be a code smell but not a very strong one. I usually only split up methods from classes when the class gets too big, the class has too many dependencies or the methods don't have shared state.
My question: should all dependencies of a class be consumed by all its functionality i.e. if different bits of functionality use different dependencies, it is a clue that these should probably live in separate classes?
It is a hint, indicating that your class may be a little incoherent ("doing more than just one thing"), but like you say, if you take this too far, you end up with a new class for every piece of new functionality. So you would want to introduce facade objects to pull them together again (it seems that a facade object is exactly the opposite of this particular design rule).
You have to find a good balance that works for you (and the rest of your team).
Looks like overloading to me.
You're trying to do something and there's two ways to do it, one way or another. At the SomeClass level, I'd have one dependency to do the work, then have that single dependent class support the two (or more) ways to do the same thing, most likely with mutually exclusive input parameters.
In other words, I'd have the same code you have for SomeClass, but define it as SomeWork instead, and not include any other unrelated code.
HTH
A Facade is used when you want to hide complexity (like an interface to a legacy system) or you want to consolidate functionality while being backwards compatible from an interface perspective.
The key in your case is why you have the two different methods in the same class. Is the intent to have a class which groups together similar types of behavior even if it is implemented through unrelated code, as in aggregation. Or, are you attempting to support the same behavior but have alternative implementations depending on the specifics, which would be a hint for a inheritance/overloading type of solution.
The problem will be whether this class will continue to grow and in what direction. Two methods won't make a difference but if this repeats with more than 3, you will need to decide whether you want to declare it as a facade/adapter or that you need to create child classes for the variations.
Your suspicions are correct but the smell is just the wisp of smoke from a burning ember. You need to keep an eye on it in case it flares up and then you need to make a decision as how you want to quench the fire before it burns out of control.
I have 2 databases that my site uses including a central user database that relates to other site-specific databases.
Sometimes it is adequate to call new User(array('db'=>'adapter1')); (but never convenient); other times, though, such as when declaring relationships between tables on different databases, there is no way to do this.
Does anyone know a way to specify which database adapter to use from within the Zend_Db_Table_Abstract class?
Thanks!
Getting back to this pretty late, but none of the answers here quite did it for me. A select few of my database models needed to use 'tdb' and the following code was added to each of those classes to have that happen automatically:
protected function _setupDatabaseAdapter()
{
$this->_db = Zend_Registry::get('tdb');
parent::_setupDatabaseAdapter();
}
I thank you all for your suggestions along the way!
Zend_Db_Table_Abstract provides a static method to set the default database adapter. Do this as follows:
Zend_Db_Table_Abstract::setDefaultAdapter($adapter);
Now, all your Table objects will use your adapter by default.
Note: the online docs sometimes don't make this obvious, so your second best place to check is in the API here: http://framework.zend.com/apidoc/core/
You could set the class variable $_db to the correct adapter in the constructor.
global $adapter1; //There are better ways than using a global variable
$this->_db = $adapter1;
Assuming the adapter object can be referenced in the constructor. That doesn't seem to portable, but I believe it would work.
The init function can be used, it is not used in Zend_Db_Adapter_Abstract, can be used in your class to setup whatever needs to be done. _setAdapter accepts a string naming a Registry Key.
public function init()
{
$this->_setAdapter('tdb');
}