Added a draft on programmatic code manipulation #349
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| ### Creating a new package | ||
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| ```st | ||
| package := self packageOrganizer ensurePackage: 'PackageName'. |
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This is P12 only so maybe the name of the article should be renamed?
| package := self packageOrganizer ensurePackage: 'PackageName'. | ||
| ``` | ||
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| In Playground, you can use any object or class instead of `self`: |
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The playground have a self so we can use the same code.
| package removeFromSystem. | ||
| ``` | ||
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| **Be careful!** In Pharo 11 and earlier, this will not properly remove classes from the system. So make sure to remove all classes before you remove the package. |
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In Pharo 12 we can also do:
self packageOrganizer removePackage: 'PackageName'#removePackage: can take:
- A package name and remove it
- A real package and remove it
- A name of a package that does not exist and will silently do nothing in that case.
I use this a lot to create teardowns in tests because maybe the test failed directly and no package was generated. In that case I don't want the tear down to crash.
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| ### Creating a package without installing it | ||
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| _(how to create an instance of a package without installing it into the image? - e.g., for testing)_ |
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By definition we cannot because currently we consider that code is installed if it is in a package.
If you want to manipulate packages that are not in the global organizer you can create a new organizer:
PackageOrganizer new(Note that this name exist only in P12+)
Or better, create a new environment that will have a new package organizer (because the environment of an environmentless organizer will still be the global environment)
SystemDictionary newOr to avoid hard references:
self class environment class new| builder := Object << #MyClass slots: { }; package: 'MyPackage'. class := builder install. | ||
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| The first statement will return an instance of `FluidClassBuilder`. The second statement will build the class, install it into the image, and assign it to the variable. If `MyPackage` does not exist, it will be created. |
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This is false in P12.
We had:
- FluidClassBuilder
- ShiftClassBuilder
- ShiftClassInstaller
FluidClassBuilder was created with the fluid syntax. When you wanted to install it, you had the create a ShiftClassInstaller that was delegating the building to the ShiftClassBuilder.
But this had some flaws:
- The FluidClassBuilder could not manage to build a class with a name for the superclass instead of a class object. This was bad for code generation because it meant that the superclass had to exist when you wanted to define it (even if you did not build anything)
- The ShiftClassBuilder did not had a lot of API and some other API was complex because only used internally by the installer
- The API of both was kind of close but not exactly the same and this was confusing
In P12 I merged both of them inside the ShiftClassBuilder (There is no FluidClassBuilder anymore). And I tried to make sure both strength were kept.
| Here is an example of how you can create a new class without installing it into the system. You can do that by sending `build` message instead of `install` as in the previous example. | ||
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| ```st | ||
| builder := OrderedCollection << #MyCollection.myCollectionClass := builder build.myCollectionClass compile: 'generate: aNumber "Generate aNumber random integers" | rand | rand := Random new. aNumber timesRepeat: [ self add: (rand nextInteger: 100) ]'. myCollection := myCollectionClass new.myCollection generate: 4. "a MyCollection(60 5 40 11)" |
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This is weird on Github I don't see the lines returns well. I hope it's just a display problem.
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