Sunday, 20 December 2015

Sending REST API messages with Delphi to Parse.com

Parse.com is one of the most interesting cloud base solutions I have found so far, and most importantly; basic accounts are for free (up to 30 requests/second, after that is when you have to pay). Using Parse.com I can keep track of my applications, using the Analytics feature. This is an easy way of knowing how many installs you have running and also it provides cloud storage to add some more details etc. I'm using this module for my project "Flickr Photo Analytics" as I currently have over thousand downloads but I don't have a clue whether the app is being used or not. Here is where the Analytics feature of parse.com gets really handy.

Embarcadero has its own AppAnalytics but I just wanted something that I could handle on my own with an easy setup. I have been using Parse for a while for few mobile applications and now I've decided to extend it to my windows desktop applications.

The idea is very simple. Every time the application is used, it will send a notification to Parse.com via REST API. Parse.com provides several communication protocols for different languages e.g. Java, Javascript, .NET, etc. but unfortunately not for Delphi. Here is why I decided to write about it as I haven't seen anything on the Internet and it could be interesting for many users out there.

To use it in Delphi, we can use the REST API via IdHTTP component. On their website they provide the syntax using curl and here is the correct translation to use it with Delphi and that works:

Curl:


Delphi:

With just this little piece of code, the Analytics feature of Parse will start tracking down your installs. It's not a real time tracking so it takes time to appear on the dashboard. Once you have your applications there, you can review the stats:


As I'm not expecting any traffic at all in my app it is really a good solution and it serves my needs. I also have a small android app that pulls from there so I can read some of the stats published by my app anywhere I go. In the end it all lies to connectivity and what's the best and easy way to achieve it. Using this approach didn't take me long at all. 

I hope it can be useful to the community.

PS: If you know any better solution out there, please do let me know!.

Jordi

Sunday, 6 September 2015

How to use Eclipse for Ruby on Rails

I have been trying to use different alternatives to run Ruby on Rails locally with available tools in the market. I have used nice editors like Sublime Text 2, notepad++ and others but I really wanted a programming IDE that I could interact with (navigate through the classes, files, etc. with easy clicks). I tested also Rubymine which is the Ruby on Rails IDE but still I wondered if there was another solution available. Then I discovered that I could use one of my favourite editors...eclipse with the DLTK (Dynamic Language toolkit) to achieve my purposes.

In this post I will cover the necessary steps you need to do to get your eclipse IDE up and running to become your Ruby on Rails IDE.

First you need to get a version of eclipse. (The Eclipse Java EE IDE for Web Developers in my case)

For this article I will use the Eclipse Luna SR2 version so everyone has a reference. You can use the version you currently have installed as the DLTK packages can be installed separately.

Once eclipse is up and running, go to Help menu and Install new software. A new window will open and in there use the following URL:

   dltk - http://download.eclipse.org/technology/dltk/updates-dev/latest/


Select the packages DLTK and DLTK test and click Next.


Now you can create Ruby Projects:


Once we want to create a new project, the system will ask for an interpreter. We will have to configure where ruby.exe is located:


Click on Configure interpreters and add a new ruby interpreter pointing to the location where your ruby files are.


Now you can add your files into the project and start working with it. Here is a simple example that I have coded for this article that you can test:

calculator.action.rb
class Calculator
  def sum(i,j)
    return i+j
  end
end


calculator.action.test.rb:
require 'test/unit'
require_relative 'calculator.actions'

class TestCalculator < Test::Unit::TestCase
    def SumIntegers
      test = Calculator.new
      expected = test.sum 3,2
      puts expected
      assert_equal expected, 5
    end
end

If you try to run this in eclipse, an error is thrown in the console:

C:/luna/eclipse/configuration/org.eclipse.osgi/898/0/.cp/testing/dltk-testunit-runner.rb:252:in `block in <top (required)>': uninitialized constant Test::Unit::UI::SILENT (NameError)

To fix this, you need to open:

C:/luna/eclipse/configuration/org.eclipse.osgi/898/0/.cp/testing/dltk-testunit-runner.rb and solve this by commenting out:

#autoRunner.output_level = Test::Unit::UI::SILENT
and adding the following:

autoRunner.runner_options[:output_level] = Test::Unit::UI::Console::OutputLevel::SILENT

as shown in the image:

and run the test again.

Now your IDE is ready for action.
Jordi

jqplot integration with ASP.NET MVC

I haven't been writing for a while and it's not always easy to find time to write about interesting stuff. I must say that I wish I had enough time to post all what I have been learning for the last past years, but I will try to keep it up. Today I'm bringing you an interesting post about jqplot integration with ASP.net MVC. I have been using ASP.NET for quite a while now (more than 5 years) and I hope this post could help you with the integration of jqplot as I faced some challenges that I'm resolving here.

jqplot is a plotting and charting plugin for the jQuery Javascript framework. It's very pluggable and really easy to use.

jqplot can be easily installed using Nuget package from VS:

Here is a simple example from the website:




As you could see, integration is quite simple and to plot the data, this one needs to be formatted in the format of a set [Date, value] to be displayed correctly. So here is the first challenge as we need to find a way to populate this list from our controller and then pass the correct formatted list to our jqplot function.

I'm working on an application called Flickr Photo Analytics. This application is able to connect to your Flickr stream and retrieve some useful stats that you can keep track overtime. The base application is written in Delphi and now I'm developing the web interface that goes with it using ASP.net MVC. For this article I will use the examples from my source repository.

The best way to approach this problem is by creating a new ActionResult in the controller that will build the relevant data (data that we want to display and in the correct format -> [Date and Value]). Then via javascript, I will use an AJAX (Asynchronous JavaScript and XML) call to call the action method from the controller and retrieve the data in JSON format. One the data is back, I will generate the list in the correct format so jqplot can plot the data.

Here is the code from my controller:



This code loads an xml file containing some relevant data from my application and according to an id that can be passed as an argument in the url, it will return a different JSON list.


The view only needs a div with an id, in this case, chart1 that will be automatically populated with a graph by jqplot once the following javascript is loaded:


The javascript will receive the results from the JSON call in a stats variable. Once we get the whole content of the variable, we need to build the correct array that will go into jqplot. This will be done using: arr.push([new Date(date), value]):



The html is as follows (view):

Loaded units required for jqplot and the div required to display the chart.


And the final result can be seen here:

Check out the properties that I have enabled for jqplot as I've use it for quite a while and I like the way I can configure it.

Any questions, please ask!.

Jordi.