Recently, the company I work for has given me the task of unifying 2 angularjs apps into one.
While I'm trying to wrap my head around it, here are the details:
- The two apps share quite a bit of common logic
- One of the apps (main one) is public facing, the other is made for a specific customer.
- Each app currently uses it's own database, this is because the customer's app is more complex and requires more data.
- Some of the common logic of the public app is being overwritten by the customer app due to the nature of it.
As an example, the login page is pretty simple in "public" but would have an extra layer of validating a registration code in "customer" and fetching the right data from the DB for this code.
I am trying to figure out how to I unify them both into 1 app, while having the ability to throttle between app modes or something similar
There is a way to tackle this using DDD (Domain Driven Design). Make a clear cut of the domain for both apps. For instance, if you encounter 2 user models in 2 different domains, as this is the case, you want to differentiate between the two of them.
Where this won't give you a framework to structure your application, it will provide a clear mindset on how to structure your application and correctly naming and identifying your contexts, domain and models.
Having clear domains should make a clear cut on which models can access X resources in the database.
Throttling is also an option, but I would only do it this way if I wouldn't have to maintain one of the versions. If the development branches only towards one, deprecating the other, then it is a reasonable solution, but maintaining 2 development branches this way is very painful.
Related
I'm still sort of new to CakePHP, and I've presently created and deployed one (rather complex) application using it. It has full user and group support and I took the time to get the access tables working and everything.
Now, I'm creating a separate application. I initially just created a brand new CakePHP installation, but I later realized that I wanted to authenticate users based on my first app. They currently use different data sources. I understand that there are a couple of ways this could be accomplished, with various pros and cons. Do I:
Keep them separate, add a data source to my extension application, and port my user authentication code over?
Keep them separate, process logins with the first application, and somehow share that data with the second using a communication protocol?
Combine them into a single data source and accept the added complexity in my app?
Something entirely different?
I'm using CakePHP to create both sites, which will be running on the same host/hostname, and connecting to the same MySQL server. Users are always stored/created on the main application, and just need to be passively accessed by the second app.
Honestly it sounds to me like you could bring them together with ease. Your reasons for keeping them separate sound to me like you could just keep them separate pieces of the one program.
For example the application I work on for a living does many of these things. Users can register, they also have access to a calendar of events, job postings, recent news, and about 25 other modules. They are just different parts of the program.
You could have one application that has a route like /users/register which the users controller takes care of registration. Then you can have another part of your application that routes to /calendar/.... where the calendar controller will take care of the calendar logic. If you need separate calendars for students and faculty you could have routes like /faculty/calendar/1 and /student/calendar/1 which would route to different parts of your calendar controller.
It's all about modularising your application, so that you can easily maintain code that is logically grouped together. You don't have to separate them so much so that they are two different applications.
I think you will avoid many headaches in the long run.
If it makes you feel better about my opinion the software I work on that I was talking about is an enterprise solution that deals with (literally) millions of documents per day, and hundreds of thousands of users per week on the government level.
My team is maintaining a huge Client Server win32 Delphi application. It is a client/server application (Thick client) that uses DevArt (SDAC) components to connect to SQL Server.
The business logic is often "trapped" in Component's event handlers, anyway with some degree of refactoring it is doable to move the business logic in common units (a big part of this work has already been done during refactoring... Maintaing legacy applications someone else wrote is very frustrating, but this is a very common job).
Now there is the request of a web interface, I have several options of course, in this question i want to focus on the VCL for the web (intraweb) option.
The idea is to use the common code (the same pas files) for both the client/server application and the web application. I heard of many people that moved legacy apps from delphi to intraweb, but here I am trying to keep the Thick client too.
The idea is to use common code, may be with some compiler directives to write specific code:
{$IFDEF CLIENTSERVER}
{here goes the thick client specific code}
{$ELSE}
{here goes the Intraweb specific code}
{$ENDIF}
Then another problem is the "migration plan", let's say I have 300 features and on the first release I will have only 50 of them available in the web application. How to keep track of it? I was thinking of (ab)using Delphi interfaces to handle this. For example for the User Authentication I could move all the related code in a procedure and declare an interface like:
type
IUserAuthentication= interface['{0D57624C-CDDE-458B-A36C-436AE465B477}']
procedure UserAuthentication;
end;
In this way as I implement the IUserAuthentication interface in both the applications (Thick Client and Intraweb) I know that That feature has been "ported" to the web. Anyway I don't know if this approach makes sense. I made a prototype to simulate the whole process. It works for a "Hello world" application, but I wonder if it makes sense on a large application or this Interface idea is only counter-productive and can backfire.
My question is: does this approach make sense? (the Interface idea is just an extra idea, it is not so important as the common code part described above) Is it a viable option?
I understand it depends a lot of the kind of application, anyway to be generic my one is in the CRM/Accounting domain, and the number of concurrent users on a single installation is typically less than 20 with peaks of 50.
EXTRA COMMENT (UPDATE): I ask this question because since I don't have a n-tier application I see Intraweb as the unique option for having a web application that has common code with the thick client. Developing webservices from the Delphi code makes no sense in my specific case, so the alternative I have is to write the web interface using ASP.NET (duplicating the business logic), but in this case I cannot take advantage of the common code in an easy way. Yes I could use dlls maybe, but my code is not suitable for that.
The most important thing that you have to remember is this:
Your thick client .EXE process is used by one person at a time (multiple persons will have multiple instances of that .EXE).
Your intraweb .EXE process will be used by many persons at a time. They all share the same instance of the process.
That means your business logic must not only be refactored out into common units, the instances of the business logic must be able to reside into memory multiple times, and not interfere.
This starts with the business logic that talks to the database: you must be able to have multiple database connections at the same time (in practice a pool of database connections work best).
In my experience, when you can refactor your business logic into datamodules, you have a good starting point to support both an Intraweb and a thick client version of your app.
You should not forget the user interface:
Thick clients support modal forms, and have a much richer UI
Web browsers support only message dialogs (and then: those are very limited), all fancy UI stuff costs a lot of development time (though for instance, TMS has some nice components for Intraweb)
Then, to top it off, you have to cope with the stateless nature of the HTTP protocol. To overcome this, you need sessions. Intraweb will take care of most of the session part.
But you need to ask yourself questions like these:
what should happen if a user is idle for XX minutes?
how much session state can I store in memory? and what if it doesn't fit?
what do I do with the session state that does not fit into memory?
This is just a start, so let use know when you need more info.
If it gets very specific to your app, you can always contact me directly: just google me.
--jeroen
I think if you move your application to n-tiers will be a better solution, it will be easier after that to be used by the desktop and web applications.
you already made the first part by decoupling the business logic from the presentation, you can use RemObject SDK or DataSnap that bundled with Delphi.
after that you will have working desktop application, and you can use Intrawebm Asp.net or what ever for web part, and in this way you will not have to duplicate the business logic again for the web part.
usually converting desktop application to web not easy as you thought, because they work in different environment, and you need to build each one as it's nature.
Here's my problem. I built a web app, and naturally kept the data in a database which describes that app's domain. Afterwords, I built another web app for the same organization, and used a seperate database to describe that app's domain and store data... and naturally a couple more projects came up and for each app I've isolated it's data to a single database. Deveolpment wise, I think it's ok, as I can maintain changes to the data structure and data at the app's database.
Considering these apps belong to the same organization, there tends to be plenty of data replicated between them, like department names, job titles, shop names, etc. Most of these tables hold the same data, but are not exactly the same in each database, and are not always used by all of the apps. Changes to this data, though, needs to be changed at all the apps (sometimes in a diferent ways) creating a growing management "hassle".
So I've been think of a way to get some syncronization between the data. I want an easier management - update at one app (or a central app) and update all the databases as needed by each app - and also a better way to share data between apps (like maybe mash up data from differnt apps in a new app to alow specific analysis). Most of the data I'm refering to is used as contraints more than being core domain concept, describing the organization rather than describing a particular domain.
I'm looking for opinions on some ways to get this done.
My first idea was to grab comun data structures, like the department names' table i mentioned, and stick'em in a core database. Any updates to the data would be done at this database, through a dedicated web app, and I'd apply some sort of Observer or Publisher / Suscriber Pattern for these changes - on changes the app would notify observing apps (through there dedicated webservice) that the changes occured and allow for the app to grab the new data and use it as it needs. GUIDs could be user as a reference to identify the same data throughout the apps. Also, I could build web services for read and search operations that don't need to be in a specific app's database, but could be useful to it.
A second idea would be that each app manage it's own data, and the apps could observe one another. A change in one could notify others that share the same data structure that the change occurred. I could still use some GUIDs and even build services on any of the apps. I think this would also be less excessive in terms of duplication of data, but might be harder to manage as each app would eventually be coupled to other apps, and I would some how have to distribute responsabilities as to which app controls what information.
I'm really curious as to something of this genre of data distibuition and syncing would work and even be recomended. Opions and other ideas are more than welcome!
What you describe here is a typical case for a "Master Data Management" system. EAI vendors (Oracle, TIBCO, IBM) offer such products. They resemble your first solution, being centralised databases with synchronization processes, detecting changes in external data sources, grabbing the changes and synchronizing data out to other external databases. They also provide a user interface to change master data directly.
MDM software are expensive, but you can implement a custom solution which will be - at least initially - cheaper than purchasing one. Both of your solutions make technical sense but there is a difference in their manageability.
The first one is better, if you can dedicate a responsible person/organization to take care of it and the business owners of your services can agree on making changes via this new centralised system.
The second solution shares the responsibility between the service owners. The hard task here is to identify the owner of each type of information (business object).
I cannot advise a solution without a deeper knowledge of your systems and organizations, but I hope I could give some ideas.
I am going to be creating a work order system with three roles
The "client" - The client can request projects to be completed by the worker. The project must be selected from a list of templates and various sub options all referred to as a campaign (campaign types come and go throughout the year)
The worker - The worker must be able to view work orders and mark them as accepted/rejected, work in progress and completed.
The overlord - He/She needs to see stats concerning the activity of the other two types of users.
So.
This is a web app. But a very simple one in terms of logic. Could something like drupal handle this? Or would I have to write my own modules? The other out of the box aspects of drupal make it attractive (admin, user creation, news feeds, etc...)
I have looked at Views and Webforms. Views seems great for querying and displaying data from the work order database (great for a portion of all three roles), but I am not clear as to how I interface with my work order database when creating and modifying work orders.
Webforms doesn't see to be the answer, I am sure I just missing something right under my nose.
Any hints in which direction to look would be great!
Thanks.
If you use a simpler, less powerful CMS, you may save time with the learning curve but lose time struggling with a less flexible framework. Also: Check how active the developer community is when evaluating Open Source software. You'll need support.
Views and Webforms may be tools that you'll end up using but what you're really talking about is work flow. You could build your own work flow with a combination CCK and views, yes. There are also work flow modules.
Are you and IRC user? See: http://drupal.org/irc
I am pretty certain that you can do this with drupal. I would suggest looking into using an easier CMS than drupal for something simple like this. Using something like MediaWiki for this application might be quicker to develop and have less of a learning curve. If you don't mind putting in the time to learn drupal, I think you will ultimately have more freedom.
First of all, don't underestimate Drupal's learning curve. Especially if your PHP and/or programming skills are relatively new. Drupal does a lot of things in it's own way, and it's good to know that way.
Secondly, Drupal is (imho) made first of all for outward facing sites, it can have a lot of stuff just for the users and not for the public, but a lot of its functionality is made for the CMS part of the system. You might consider using a more framework-style system like Zend Framework, which components are a bit more "loose" but also offers less functionality out of the box.
Thirdly, depending on what a work order is and how it should be treated a custom module could be needed. If a workorder has a really simple datamodel, it could probably be done without programming, but if it is complex you'll have to fire up your favorite editor. Don't worry, making a module sounds scarier than it really is.
I don't know how good your knowledge of drupal is, but to me this has CCK and Views2 and user roles written all over it.
Basically, use CCK to create your content types (remember the user reference field might come in handy to assign a node/record to a particular user)
Then create views for each user group (they could be shared, as you can assign them to more than one role type)
Creating a view where you filter the cck user reference field by the user looking at the screen may also come in handy here.
OKAY, there might be a little bit more to it than that, but what you want is doable.
UPDATE: To protect your site from unwanted eyes, check out the site security module as it puts a security wrapper around all of your website.
Views - Create lists - allow access by user roles
CCK - Define your own content types (add your own fields)
I am currently working within a custom framework that uses the database to setup a Page Object which contains the information about Module, View, Controller, etc which is used by a Front Controller to handle routing and the like within an MVC (obviously) pattern.
The original reason for handling the pages within the database was because we needed to be able to create new landing pages on the fly from within a admin interface and because we also needed to create onLoad and onUnload events to which other dynamic objects could be attached.
However, after reading this post yesterday, it made me wonder if we shouldn't move this handling out of the database and make it all file structure and code driven like other frameworks so that pages can be tested without having the database be a component.
I am currently looking at whether to scrap the custom framework and go with one of the standard frameworks and extend it (which is what's most likely right now), but I'm wondering whether to extend the framework to handle page requests through database like we are now or if we should simply go with whatever routing / handling mechanism comes with the framework?
Usually I'm pretty lenient on what I will allow to go on in a "toy" application, but I think there are some bad habits that should be avoided no matter what. Databases are powerful tools, with reasonably powerful languages via stored procedures for doing whatever you need to have done... but they really should be used for storing and scaling access to data, and enforcing your low level data consistency rules.
Putting business logic in the data layer was common years ago, but separation of concerns really does help with the maintainability of an application over its lifespan.
Note that there is nothing wrong with using a database to store page templates instead of the file system. The line between the two will blur even further in the future and I have one system that all of the templates are in the database because of problems with the low budget hosting and how dynamically generated content need to be saved. As long as your framework can pull out a template as easily from a file or a field and process them, it isn't going to matter much either way.
On the other hand, the post from yesterday was about generating the UI layer elements directly from the database (at least, that's how I read it) and not an unusual storage location for templates. That is a deep concern for the reasons mentioned... the database becomes locked to web apps, and only web apps.
And on the third hand, never take other people's advice too much to heart if you have a system that works well and is easy to extend. Every use-case is slightly different. If your maintainability isn't suffering and it serves the business need, it is good enough.