The Geeky Introduction to Agile Toolkit

Agile Toolkit is a collection of classes for multi-purpose web user interface development. Packaged as a framework, Agile Toolkit can also be used as a library, bypassing many of the web initialization routines, making it perfect for integration purposes into your existing environments or 3rd party products. Agile Toolkit is well suited for your growing product, starting from the early prototype and up-scaling to a distributed multi-server solution capable of processing thousands of requests per second.

To simplify the understanding of Agile Toolkit, I have focused around 3 major landmark features of Agile Toolkit which are: business model, user interface and javascript integration. Agile Toolkit contains over a hundred unique features and tricks and has solutions for almost every situation in your development and deployment cycle.

Agile Application Life-cycle

We want our software to last for years and remain flexible and extensible forever. But we also want to start from a simple prototype and build it all the way to scalable deployment. Below is the explanation of how you will be able to manage the three stages with Agile Toolkit.

Prototyping stage

When using Agile Toolkit to build your early prototype, you can massively reduce the amount of developers labor by planing your models and composing your user interface from a ready-to-use Views (widgets). The views are of an object-oriented nature and will mold into any UI element in the hands of a skilled developer familiar with the power of inheritance. Contrary to some frameworks, Agile Toolkit omits a lot of configuration parameters and options in the core classes but promotes developers to extend and override default behaviors.

For a person who understands the way of Agile Toolkit, putting together a data management back-end is a matter of minutes. The same applies to some of the PHP project builders which populate your back-end with CRUD pages. Agile Toolkit remains true to it's principles and keeps the code flexible allowing you to enrich the user interface and keep adding new elements inside other elements — crud into page, expander into crud, tabs into expander, crud into tabs and so on.

When it comes to front-end, a developer would produce a set of custom project-specific templates which are later modified and tweaked by the designer or optionally, the other way around. The same data model layer is re-used in the frontend and the backend. Integrated ORM and Active Record, funnel the power of Relational SQL to optimize your queries and create minimum requests per page, which is very important for the further stages of your application.

At this stage the out-of-the-box User Interface will be very useful and time-saving for you.

Fully-functional Product

Eventually you need to convert your prototype into a polished and well-designed product. With other frameworks you need to start from scratch or do some heavy lifting, but Agile Toolkit allows you to gradually enhance functionality. The code refactoring is an essential part of developing with Agile Toolkit. The roles of 'User Interface Developer' and 'Business Logic Developer' are separated and each have their own ways to separate out code components, which are re-used,and still retain the ability to custimize them as needed.

At this stage you will get to love the flexibility of Models. You will get to extend models and produce joins to gather required data. Let's look at example:

Example

Let's assume you need to show list of your user profiles. The View would be heavily reused across your applications — you would want to show user list on your "most active users" page, "who follows me" page and "currently logged in" page. In all cases you are showing the same presentation logic — list with pagination. It's wise to create a separate view: "View_UserLister" which will provide the right output on your pages.

While the presentation logic remains un-changed for every page, the data may differ. A good solution is to have several sub-classes of your "Model_User" which reflect the proper data. Those descending classes will only tweak conditions, ordering, and some other aspects of your query. Still, in all cases, only one query is produced which gathers up all the data without reliance on caching or traversing models inside the loop.

Your next challenge might be the different "templates" for the View_UserLister. Agile Toolkit allows you to specify a different template for each individual instance of the view. This way you can add additional fields into a particular page. Your other challenge might be — how to calculate the field? How would you show a list of users which is "followed" by a currently logged-in user? A simple SQL sub-select will deal with it most efficiently. Agile Toolkit allows you to tweak an existing Model by adding additional query fields without changing the master model. This is really important because you know that the stable part of your application is not going to be affected by your changes and therefore does not require re-testing.

The next challenge you might face in conventional development is reflecting on database refactoring, field alias consistency and debugging queries. Agile Toolkit allows you to extract queries from each model with table-name, conditions, and joins embedded into the query. You can further modify and extend the query but should your database logic change, you only need to update your master model, and any references to that model would start using the proper query. For example, if you add "soft delete" to your "user_follows" table, normally you would need to review your code and modify the queries. With Agile Toolkit the condition will be automatically embedded into queries produced from the respective model.

Another problem Agile Toolkit will be solving for your team is the collaboration issue. Because all the functionality is nicely distributed, you can easily separate responsibilities in your team and assign developers on tasks such as — produce business models and unit tests, create administration interface, create front-end pages, build library of re-usable views, build custom jQuery UI widgets or JavaScript behaviours; and never have clashes between different developers and designers. Your produced code will also be consistent and easily maintainable by developers who join the development later.

Scalability Stage

With the incredible efficiency and flexibility of requests you can achieve no more than 10 requests for each page requested. Furthermore AJAX interaction will require considerably less CPU power which greatly contributes to performance of your Agile Toolkit based software. You can still write inefficient software with Agile Toolkit but to avoid it I am providing a performance guide in this book which will focus on performance.

Certainly we both understand that any generalization, frameworks or libraries can't be offered without overhead, but by making the right choices it's possible to have a perfect combination of software flexibility and performance.

Agile Toolkit has a powerful and fast template parser and query builder with low complexity. The typical page of Agile Toolkit would run at 20-120 requests per second (without cache) while other frameworks and CMS systems might be only able to handle around 1-3 requests per second. That is still slower than a raw PHP code, but it is a small price to pay for all the benefit you get.

Realistically, with some server tuning, reverse proxy using php-fmp, and PHP acceleration, you can host up to 200 simultaneous users on a single server with a complex business logic, so you wouldn't need to worry about scalability for a long time and certainly will save a lot on your hardware requirements.

Adding Output Caching

Your SQL might already be doing some caching for you, but some sections might be too difficult to render efficiently. An example would be a comment section. You can have a NoSQL database such as MemCache for holding your comment section data organized by article_id. With Agile Toolkit HTML caching is easy. Redefine render() function to either save or retrieve HTML content from the cache. You can also implement a generic caching solution which could be implemented through a controller. Initialize your object, set its model and add a caching controller which might just change the way rendering is done.

Adding Input Caching

If certain data takes too much time to be prepared it might be easier to save it into another storage. In Agile Toolkit, the most common-used models are based on "Model_Table". This class is designed for use with relational databases. You can still use the basic functionality of Data Controllers and send or retrieve data from a non-SQL source. Initially they are designed to support non-relational model, but they can be used with relational model too by calling the controller's methods directly.

This gives you a transparent enhancement to your models which can cache the data in a faster storage but use SQL as a fall-back.

Building Service APIs

The design of a View permits the use of any kind of model. For a non-relational model, you can implement your own API Data Controller which would retrieve input data through JSON from your internal service. The model and the arguments are initialized during the first pass of your software execution (init phase) but the collection of data is done during the render() phase. That means you can send simultaneous requests to your internal APIs during the init() of your page and then collect results during render(). Not only will Agile Toolkit intelligently decide which objects need to be initialized on your page, but the transparency will be invaluable during your development, deployment and testing.

It's a common and great practice to share Models between different components. Your front-end may rely on the set of models for meta-data, but would route requests into API. Your internal API service would also relay on the same models, and secured by your custom internal authentication protocol it would rely on the data source to retrieve necessary data and prepare it in the exact same format as front-end would expect it.

Stored Procedures

Eventually you might have a need to perform heavy processing in the database. Stored procedures is often a great way to tune up performance, although they shouldn't be relied on in the earlier stages of your application.(Think about it — stored procedure languages are so immature and difficult to develop in, it's a nightmare to produce any decent procedures). Agile Toolkit has all the support for executing expressions, calling user-defined SQL functions or using specific extensions of your database of choice without bypassing ORM. You can add new expressions and further customize the query building class: DSQL

Code Review Services

If you are building your first major project in Agile Toolkit, take advantage of our code-review services. We maintain a team of highly experienced web developers who have seen many complex and extreme web solutions. Share your code with our team and we will be able to provide you with comments and feedback on the organization of your code as well as provide training under NDA and specifically tweaked for your project needs. The other framework you were considering for your project earlier wouldn't even have a skilled and motivated team to advise you.

Developing Commercial Products with Agile Toolkit

Many commercial PHP products (such as chat system, support systems, etc) were developed without the use of frameworks and distributed as closed-source applications simply because frameworks introduce too many obstacles into your own distribution platforms. We understand very well that some projects can be open-source but there are always projects which must be closed-sourced. We aim to support and help you build your closed-source commercial software and Agile Toolkit is very well suited for bundling with your application.

Commercial Add-ons

By promoting a commercial initiative on top of an Open-Source framework we are able to produce good-quality add-ons for a reasonable cost. If you intend to share your commercial add-on with the rest of the world, we will help you to distribute and sell it. Please contact us for more details.

The Bottomline

Agile Toolkit is simple to understand and learn yet it is a very solid and deep framework with virtually no limitations. There are almost no excuses to NOT use Agile Toolkit. If you are still unsure if you should adopt Agile Toolkit, use the contact form to ask questions and you will receive a reply from someone on our development team who uses Agile Toolkit on their projects on a daily basis.