Python is an incredibly versatile programming language that can be used for data science projects, data analysis, machine learning, and data visualization.

Code has cosmetic and intrinsic characteristics. See examples demonstrating how to achieve the same intrinsic with different cosmetics and vice versa.

Pivotal announced yesterday that Groovy 2.4 And Grails 3.0 will be the last major releases under Pivotal sponsorship. This is big news that has not surprisingly created a lot of buzz in the blogosphere. In this post, I describe some of the questions that others and I are wondering about and speculate on Groovy's future. Groovy’s Future is in Doubt Sadly, it appears at this time that is more likely than not that Groovy does not have a significant future ahead. It would seem that the developers of this program are going to allow it to rot away instead of taking any action steps to potentially stave off such an outcome. It seems from the statements put out by Pivotal that they are likely to nix Groovy due to a general lack of use among its customer base and the inability of the company to keep up with everything that it needs to in order to continue to offer this service to those who are still using it. We are sorry to say that it appears that Groovy is on its way out even though we don’t want it to be. Sometimes, that is just the way that these things go. After reading multiple Reddit references to this announcement, my initial thought was to see what Guillaume Laforge had to say about this. Apparently, a lot of people had the same idea because I encountered a 503 error when trying to access his page. Fortunately, I did not have to wait for Laforge's blog to be available to get more insight from him on this announcement because there were a couple of interviews with him regarding the announcement already online: Voxxed.com's Pivotal’s "Sad and Odd'' Decision to Set Groovy Adrift and InfoQ's Pivotal Pulls Groovy/Grails Funding. Since that time, Laforge's blog is available again and has a post on the subject calledThe Groovy project is looking for a new home. Another person frequently and deservedly associated with Groovy, Graeme Rocher, has also posted on the subject: The Future of Groovy and Grails Sponsorship. Laforge and Rocher were co-founders of G2One, which was acquired by SpringSource in late 2008. VMWare then acquired SpringSource about one year later (and VMWare had been owned by EMC since late 2003). EMC would later announce the spin-off of Pivotal in 2013 and Pivotal today announced the dropping of Groovy support as of 21 March 2015. Questions, Answers, and Speculations The posts referenced here in my post have collectively answered some of my questions about Groovy and at the same time presented additional questions. Why is Pivotal dropping the financial support of Groovy and Grails? Answer: Pivotal's announcement: "The decision to conclude its sponsorship of Groovy and Grails is part of Pivotal’s larger strategy to concentrate resources on accelerating both commercial and open source projects that support its growing traction in Platform-as-a-Service, Data, and Agile development. Pivotal has determined that the time is right to let further development of Groovy and Grails be led by other interested parties in the open source community who can best serve the goals of those projects." Who Might Sponsor Groovy and/or Grails Development? Speculation: Many organizations benefit from Groovy and Gravy, but many probably aren't prepared to invest as fully in their development as G2One, SpringSource, VMWare, and even Pivotal have been. An example of an organization with an obvious vested interest in Groovy's future is GradleWare. Ken Kousen has tweeted and written a blog post on the opportunity of acquiring Groovy and Grails sponsorship. What does this announcement mean for Groovy's future? Answer Mixed with Speculation: Based on Laforge's and Rocher's posts, it seems clear that the core developers plan to continue working on Groovy. However, it is understandable that if this effort is not funded (sponsored), it will have to be at a slower pace than before (I have found through personal experience that home projects take a lot longer to complete than paid projects). I believe that Groovy has strong momentum already that will continue for some time. It is vital to Gradle, is used with other open source projects and tools such as SoapUI, and could have a promising future running on Android. I primarily use Groovy for scripting and simple "glue" tools in Java applications. The language is mature and serves these purposes well and I see no reason to stop using it at this time. What does this mean for the future of the Spring Framework? Speculation: There is some concern that perhaps Spring Framework could be jettisoned next from Pivotal. This seems unlikely to me, but I didn't expect Pivotal to drop Groovy either. As much as I love Groovy and as much effect on Java and JVM development as I acknowledge it has had, I think Spring Framework has been even more pervasive in Java EE development than Groovy and Grails have been in Java SE and Java EE development. That stated, Pivotal has shown that they are willing to, as most successful businesses are, drop a product offering that is perceived as not benefiting their strategy and bottom line. I can certainly understand if this development concerns users of Spring. Is Standards-Based More Important than Being Open Source? Answer: This is a difficult question to answer that often depends on numerous contextual factors including the tools being compared, the expected length of life of the products being built, etc. Fortunately, we often don't have to choose between these as many reference implementations in the Java world are also open source. However, a point can be made that any product that is not standard (including commercial or proprietary) is subject to losing support or not being available any longer. The theory is that if standards-based products are used, one can then shift to another implementation of that standard if necessary. However, a standard is only as good as its implementations and if there is only one realistic implementation of a standard, there's not much of an advantage of transferability there. Conclusion Although I understand Pivotal's motivation for dropping Groovy, I am still sorry to hear that news. I appreciate the effort that key Groovy contributors such as Laforge and Rocher have made and I appreciate the companies that have sponsored that work. Through this sponsorship and work, we have a really nice language to use for scripting and other purposes. I hope that a sponsor can be found for Groovy, but I plan to continue to use it either way.

An in-depth look at what distinguishes some newer JavaScript frameworks like Polymer, Aurelia, Meteor, Webix, and React.

We take a look at how mobile application developers working with Xamarin can secure their apps with this free, and awesome, tool.

The source code The slides for the talk "Mobile First!" is the new cry of web designers worldwide. But how do you do it? Do you have to scrap all of your current web skills? Is it magic created by wizard-like designers which could never be understood by mere mortals? Believe it or not, with the combination of jQuery Mobile and CSS3 Media Queries, you can easily create a site that looks good on a phone, tablet, or desktop. Does Mobile-First Still Matter? Yes! You still need to look to design all features of your programs with a mobile-first mentality. People are spending increasing amounts of time on their phones, and they expect the companies that create products for them to come up with something that will enable them to continue to view those products from their phones. If you are unable to do this for them, they may simply move on to another company that can provide them with that kind of functionality. You have a lot of choices to make when it comes to the specific features that you will use and embrace, but you need to consider how going mobile first can help bolster the chances of your application being used by the masses. General Responsive Web Features The web began as responsive. Now admittedly, the web didn't do very much, so being responsive when the Internet was mainly documents was easy. HTML documents naturally wrapped to the next line and flowed down the page. Along the way, things changed. Developers began designing sites in tools like PhotoShop and wanted perfect pixel renderings of those designs. The problem with pixels is that they are not very flexible. It has always been possible to use percentages instead of pixels, but they were clumsier to work with, so pixels remained the favorite. With HTML5 and CSS3 there is more support for responsive design. Lets Meta Tags Meta tags have been the favorite of the SEO crowd for some time. Meta tags are used to define keywords, descriptions, and even redirects. Here are some rules about meta tags: They always go in the section of the page They are never displayed They consist mostly of key/value pairs: name = key and content = value Viewport The viewport is a special type of meta tag which defines the screen of a mobile device. In the example program the viewport meta tag looks like: The attributes above mean: width=device-width - converts the pixels to CSS pixels initial-scale=1 - sets the scale level user-scalable=no - turns off scaling If the initial scale is some other value than 1, the zoom can be smaller or larger. If user-scalable is set to yes, then the user sets the zoom level by tapping, pinching, or whatever zoom gesture the browser supports. Media Query Media Queries are the workhorse of responsive design. A media query is a media type and at least one expression that limits the style sheets' scope. Here is an example: @media screen and (max-width: 1024px) and (orientation:portrait) { } The above media query means: For a screen media type Define the classes only if The width is less than 1023 AND the orientation is portrait The media query begins with @media then a media type, in this case, screen. Other types are all, braille, embossed, handheld, print, project, speech, tty, and tv. You can compose complex media queries using logical operators like not, and, and only. not - is used to negate an entire media query and - used to combine multiple media features together into a single media query only - used to apply a style only if the entire query matches Finally, there is the comma-separated list which behaves like an operator. If any media queries return true, the style sheets get applied. One pattern for applying the media queries is to define the query for the narrowest device first, then define it for a tablet, and finally a desktop. Now all of these definitions are pretty loose and open to interpretation. You may need to adjust them to fit your needs. If you run the demo on a high pixel phone like a Nexus 4, which has a display of 1280x768 resolution, why doesn't it display like a desktop? The key is the viewport meta tag. This tag, which is read by mobile browsers, redefines the pixels as CSS pixels. The precise number of CSS pixels varies by device, but on the iPhone, it is 320 and on the Nexus 4 it is 384, both of which are less than the minimum of 480 pixels to be defined as a tablet. jQuery Mobile Features So far we haven't looked at jQuery Mobile features. From the get go jQuery Mobile has had responsive features. Some of which are: grid - a simple way to build CSS-based columns that can also be responsive tables - selectively hide or shows table columns based on the display width panels - create a hidden page that slides left or right to reveal itself Grids Grids have been with jQuery Mobile since the beginning. They are essentially self sizing columns that dynamically resize themselves when the size of the page changes. The number of available columns ranges from two to five. To change the number of available columns simply change the class on the root p then add or remove a p from the collection. ui-grid-a = 2 columns ui-grid-b = 3 columns ui-grid-c = 4 columns ui-grid-d = 5 columns Tables Tables were added with the release of jQuery Mobile 1.3.0. They allow for the responsive display of tabular data. There are two basic types of tables: reflow which is the default and column toggle. Reflow tables lay the table data horizontally until it reaches a minimum size, then all of the data for each row is grouped together and it re-flows down the page. In column toggle mode, each column of a table can be given a separate priority, when the data can no longer fit horizontally, the column with the lowest priority number which is still visible is hidden. This continues until a minimum size is reached or there is only one column remaining. Panels A panel is a hidden page that reveals itself by sliding from the left or right onto the page. It can support nearly any jQuery Mobile widget. When the panel is displayed, clicking anywhere else on the page will close it. Best Practices Design styles beginning with "mobile first", then go wider Use "min-width" to constrain styles Prefer percentages and ems to pixels

The author conducts two tests with differing service delay times to measure any difference in performance between reactive and synchronous programming.

This deep dive of using Logback with Spring Boot includes how to use property files to alter the default Spring Boot settings and how to create custom configurations.

I have always worked with core PHP and was always reluctant to use any CMS (Joomla, Drupal, etc). Coincidentally I never got a chance to work on any of the frameworks in PHP. But in the current project at work, we have decided to use CodeIgniter. CodeIgniter is a lightweight open source web application framework. In short, it gives you a directory structure of a proper MVC pattern along with a lightweight built-in templating engine of its own. MVC pattern helps developers to separate business logic and the presentation layer. It requires a very minimal setup, unlike the famous PHP framework, Zend. Zend is mostly used in developing enterprise applications and is a vast framework, hence making the learning curve more difficult. On the other hand, CodeIgniter is easy to set up and easier to learn. Using Proper Frameworks It is so very important to apply the proper frameworks to any project that you are working on. When you use the best coding frameworks, you can accomplish a lot more than you might have ever dreamed was possible. Eliminating some of the noise and distractions that can take you away from truly accomplishing all that you need to is a big step in the right direction, and you will find that getting started with the right frameworks is probably what you need to do as a first step towards that goal. Otherwise, you will find yourself floundering for the right answers, and your projects just won’t turn out the way that you might have hoped that they would. Let’s Get started with CodeIgniter Of course, the first step is to download the codeigniter framework. You can download the latest stable version of Codeigniter from the following URL http://codeigniter.com/downloads/ . It will be a compressed file (zip file) that will be downloaded, just unzip it and keep it in a folder, say Codeigniter. Make sure you keep it inside the htdocs or webserver’s directory. Now it's time to configure the Codeigniter which initial settings to start working on. To do so, open the file config.php in your favorite editor. The file resides inside system/application/config directory. You will see an array called $config which stores all the configuration information, we will change only the following values and leave the rest as it is. /* |-------------------------------------------------------------------------- | Base Site URL |-------------------------------------------------------------------------- | */ //don't forget the TRAILING slash (/) $config['base_url'] = "http://localhost/codeigniter/"; Trust me, that shall be all to get you started. Some blogs/sites have shown many changes in this file, but you can play around with them when needed. You can change a lot about your application from this single file. Like you can store the session information inside a database, by simply setting up the config var $config['sess_use_database'] as TRUE, which is FALSE by default. You can also change the name of the session table from default “ci_sessions” to anything you like. Since none of the web applications runs without database, let me show you how to configure a database in this setup. I decided to pick this up in the next tutorial, but since it's pretty straightforward, let’s do it. To configure the database, open database.php which is located in the same directory as config.php i.e. system/application/config . Now change the values of the following array keys with the actual values of your MySQL server. $active_group = "default"; $active_record = TRUE; $db['default']['hostname'] = "localhost"; $db['default']['username'] = ""; //database username $db['default']['password'] = ""; //database password $db['default']['database'] = ""; //name of the database $db['default']['dbdriver'] = "mysql"; $db['default']['dbprefix'] = ""; //any table prefix, if you want to keep one $db['default']['pconnect'] = TRUE; $db['default']['db_debug'] = TRUE; $db['default']['cache_on'] = FALSE; $db['default']['cachedir'] = ""; $db['default']['char_set'] = "utf8"; $db['default']['dbcollat'] = "utf8_general_ci"; As you see the database configuration was also simple. Now it's time to develop a simple application using the CI framework. At the very beginning of this post I mentioned that CodeIgniter gives you an MVC pattern structure, so every part has a separate folder. Let us create a simple controller class to start with. To do this, let's create a class called Hello which will be written in the file called hello.php, stored inside system/application/controllers/ folder. The content of the file can be : (you can have a different class, after all, it's just a PHP class). class hello extends Controller { function __construct() { //call parent constructor parent::__construct(); } function index() { $output['header'] = "My page's header"; $output['content'] = "Here is the content of the webpage"; //load from from the system/application/views/hello.php $this->load->view('hello',$output); } } Dissect the code Now let us understand the code line by line. It's a controller class called hello which extends the default parent class called Controller. Extending the Controller class facilitates the execution of this controller. The constructor of this call simply loads the constructor of the parent class, which apparently is Controller. Next is the index(); function which has a special meaning in the CI framework. If it's present in a controller, it is executed automatically when the controller is loaded/executed. Now we output the data using the view part of the MVC pattern. if you notice the above code loads a view called hello which is a file kept inside the system/application/views/ folder. The file name should be the same as the name of the controller. And the data is provided in the form of an array, where header,content are the template variables, as shown below in the hello.php The above view renders the data which is passed on by the calling controller. Now let's try and test if everything works as we expected, phew! Open your browser and hit http://localhost/codeigniter/index.php/hello/ If everything is well, you should see a webpage, with a header and body content as specified in the controller. Wonder, how did that get rendered? CodeIgniter provides a very nice routing mechanism based on REST. The URL is so that you can call a specific controller and a method from inside the controller. But if you notice, in the above URL we have mentioned only the controller name i.e. hello, and not the function name index(). As mentioned previously, This is due to the fact that index(); function gets called automatically if it exists. Might it have been another function called render then the above URL would have been changed to http://localhost/codeigniter/index.php/hello/render/ The above URL which now call the render(); function from the hello controller. CodeIgniter was easy, no? If you think that was tough, just go through the steps again and I am sure you will understand. Since CI is the easiest framework and it lets you get started very quickly with the development. Happy Development!

Spring Roo is an rapid application development tool that helps you in rapidly building spring-based enterprise applications in the java programming language. Google app engine is a cloud computing technology that lets you run your application on Google's infrastructure. Using Spring Roo, you can develop applications that can be deployed on the Google app engine. In this tutorial, we will develop a simple application that can run on the Google app engine. Roo configures and manages your application using the Roo shell. Roo shell can be launched as a stand-alone, command-line tool, or as a view pane in the Springsource tool suite ide. Create it Fast and Effectively Most who create applications want to make them fast, and they want to make them effectively. What this means is that if they can figure out a way to create something that will both work for their users and also provide them with the speed of transaction that they need, then it is entirely possible that this will be precisely what they need to do in order to get the best results. Most are looking to Google search as a great way to get their apps out into the world, and it seems like this is as good of a place as any to start. Pushing out apps that can help the general population get the help they need with various projects means working with the most popular search engines in the world to make it happen. Thus, you should look to develop apps that work on Google in order to get the kind of results that you require. Prerequisite Before we can start using the Roo shell, we need to download and install all prerequisites. Download and install SpringSource Tool Suite 2.3.3. m2. Spring Roo 1.1.0.m2 comes bundled with STS. While installing STS, the installer asks for the location where STS should be installed. in that directory, it will create a folder with the name "roo-%release_number%" which will contain roo stuff. add %spring_roo%/roo-1.1.0.m2/bin in your path so that when you can fire roo commands from the command line. Start STS and go to the dashboard (help->dashboard) Click on the extensions tab Install the "google plugin for eclipse" and the "datanucleus plugin". Restart STS when prompted. After installing all the above we can start building the application. Conferenceregistration.roo Application Conference registration is a simple application where speakers can register themselves and create a session they want to talk about. So, we will be having two entities: speaker and presentation. Follow the instructions to create the application: Open your operating system command-line shell Create a directory named conference-registration Go to the conference-registration directory in your command-line shell Fire Roo command. You will see a roo shell as shown below. Hint command gives you the next actions you can take to manage your application. Type the hint command and press enter. Roo will tell you that first you need to create a project and for creating a project you should type 'project' and then hit tab. Hint command is very useful as you don't have to cram all the commands; it will always give you the next logical steps that you can take at that point. Roo hint command told us that we have to create the project so type the project command as shown below project --toplevelpackage com.shekhar.conference.registration --java 6 This command created a new maven project with the top-level package name as com. Shekhar.conference.registration and created directories for storing source code and other resource files. In this command, we also specified that we are using Java version 6. Once you have created the project, type in the hint command again, Roo will tell you that now you have to set up the persistence. Type the following command persistence setup --provider datanucleus --database google_app_engine --applicationid roo-gae This command set up all the things required for persistence. It creates persistence.xml and adds all the dependencies required for persistence in pom.xml. We have chosen the provider as DataNucleus and the database as google_app_engine because we are developing our application for google app engine and it uses its own data store. Applicationid is also required when we deploy our application to the Google app engine. Now our persistence setup is completed. 8. Type the hint command again, Roo will tell you that you have to create entities now. so, we need to create our entities' speaker and presentation. To create a speaker entity, we will type the following commands entity --class ~.domain.speaker --testautomatically field string --fieldname fullname --notnull field string --fieldname email --notnull --regexp ^([0-9a-za-z]([-.\w]*[0-9a-za-z])*@([0-9a-za-z][-\w]*[0-9a-za-z]\.)+[a-za-z]{2,9})$ field string --fieldname city field date --fieldname birthdate --type java.util.date --notnull field string --fieldname bio The above six lines created an entity named session with different fields. In this, we have used notnull constraint, email regex validation, date field. Spring Roo on the app engine does not support enum and references yet which means that you can't define one-one or one-to-many relationships between entities yet. These capabilities are supported on spring MVC applications but spring MVC applications can't be deployed on app engines as of now. Spring Roo Jira has these issues. They will be fixed in future releases(hope so :) ). 9. Next create the second entity of our application presentation. To create a presentation entity type the following commands on Roo shell entity --class ~.domain.presentation --testautomatically field string --fieldname title --notnull field string --fieldname description --notnull field string --fieldname speaker --notnull The above four lines created a jpa entity called presentation, located in the domain sub-package, and added three fields -- title,description and speaker. As you can see, the speaker is added as a string (just enter the full name). Spring Roo on google app engine still does not support references. 10. Now that we have created our entities, we have to create the face of our application i.e. user interface. currently, only GWT-created UI runs on the app engine. so, we will create GWT user interface. To do that type gwt setup this command will add the GWT controller as well as all the UI required stuff. This command may take a couple of minutes if you don't have those dependencies in your maven repository. 11. Next you can configure the log4j to debug level using the following command logging setup --level debug 12. Quit the Roo shell 13. You can easily run your application locally if you have maven installed on your system, simply type "mvn gwt:run" at your command line shell while you are in the same directory in which you created the project. This will launch the GWT development mode and you can test your application. Please note that applications do not run in the Google chrome browser when you run from your development environment. So, better run it in firefox. 14. To deploy your application to the Google app engine just type mvn gwt:compile gae:deploy it will ask you for app engine credentials (email id and password).

This article presents an introduction to the Querydsl series with the goal to highlight the difference from JPA Criteria.

If you're writing code for a web application using Java, read this post to learn about how to work with the newest updates to Eclipse.

In this Python Nose tutorial, we deep-dive into the Nose framework, a test automation framework that extends unittest and further leverage Nose to perform Selenium test automation.

Learn more about class loading in Java and its performance impact.

This article presents an easy guide on how to build an application that uses time-series data to forecast trends and events using TensorFlow and QuestDB.

Know more about Ktor, a Kotlin Web Framework.

Learn how Cypress compares to Selenium, a better choice in the software testing world, in terms of speed test, architecture, language support, and much more.

Having plenty of feature-rich components, tools, and libraries, front-end development has been one of the most exciting and multi-faceted tools.

For those occasions when one storage account just won't do

JavaScript is one of the most important languages today. Let's take a look at how JavaScript has evolved in its short history and where it is headed next.