Updating legacy codes
A legacy code is any application based on older technologies and hardware, such as mainframes, that continues to provide core services to an organization.Legacy applications are frequently large and difficult to modify, and scrapping or replacing them often means re-engineering an organization’s business processes as well.
But when it does, oh goodness is it nice, as well as very open and flexible.Fast-forward a couple months and the initial Bbii2 from Sourcetoad has gained some traction and we can now circle back to it and ‘Packagist-ize’ it. Why would one want to have a code library as a package? `composer global require "fxp/composer-asset-plugin" -o -v` `composer install -o -v` `php console/yii app/setup --interactive=0` At this point we should have a basic Yii2 web-app up-and-running: Package skeleton Now that the parent application is setup we will move on to dealing with some of the paperwork of creating the package. Each vendor can, and many time does, have multiple ‘packages’ within them.Some simple, some massive, some you may never use (but other packages do). We’ll now make our own vendor directory and step into it: The internal structure of each package varies widely as the functionality and usage of packages vary.Re-implementing applications on new platforms in this way can reduce operational costs, and the additional capabilities of new technologies can provide access to functions such as web services and integrated development environments.Once transformation is complete and functional equivalence has been reached the applications can be aligned more closely to current and future business needs through the addition of new functionality to the transformed application.There is no authoritative source on how to construct the internals of a package.
However our top two levels for this specific usage is similar to this other package: The autoloader is VERY important as it will determine the namespacing used in the “use” statements of our current logic, as well as how the package will get found and auto-loaded by composer on install or update. Now let’s commit the changes: Now we do a global find/replace and changing all the namespace “use” statements throughout the library.
This is well outside the scope of this tutorial but as an example: Currently in “//vendor/sourcetoad/bbii2/src/Module.php”: namespace frontendmodulesbbii; use frontendmodulesbbiimodels Bbii Member; use frontendmodulesbbiimodels Bbii Spider; use frontendmodulesbbiimodels Bbii Session; use Yii; ...
class Module extends yiibase Module Testing the package Now we want to test the package within our current test application, following the install process found in the and add the following to our applications “./frontend/config/web.php” and add a menu item to the top main menu: Next we head over to https://packagist.org/ to add the package to the composer list.
This walk-through series only touches on the very edges of what each technology’s capabilities are.
With their powers combined, dependency management becomes a light-hearted breeze. ), add a release tag, push it to origin, and you’re done.
Primary issues with a legacy system include very old systems with lack of documentation, lack of SMEs/ knowledge on the legacy systems and dearth of technology skills in which the legacy systems have been implemented.