Creating your own self-hosted PARSE server

As you might be aware, PARSE service is shutting down beginning of 2017. This was a really great solution to quickly spin up the infrastructure needed to build an app. I still have some of my apps relying on that infrastructure and I think it's time to make the move to my own self-hosted PARSE server (for local Development). Here you will find a quick guide through the initial configuration required to have your PARSE server up and running in no time.

PARSE is actually really easy to set up. You just need a NoSQL DB (MongoDB in this case) and then get the latest source code from GitHub to create your own PARSE self-hosted instance. My sandbox is a Windows 2012 R2 and I will guide you through the required steps in there.

The prerequisites are as follows:

• Node 4.3
• MongoDB version 2.6.x or 3.0.x
• Python 2.x (For Windows users, 2.7.1 is the required version)

Installing MongoDB.

First you'll need MongoDB. Download the latest version of MongoDB from here. In my case I installed version 3.2.6 for Windows Server 2008 R2 and later with SSL support.

Install the complete version and once finished, go to MongoDB folder and run mongod.exe command:

Notice that I had to run the command twice as the folder that MondoDB needs was not there: C:\data\db. I created the folder manually and then ran again the executable. Now MongoDB is up and running awaiting for connections on port 27017.

Installing Node.js.
Next step is to download and install Node.js. You can get the latest version here. I will install version 4.4.4 LTS which is the recommended for most users. Download the installer and continue clicking next until it is completely installed on your machine.

Installing Python.
The required version for Windows is 2.7.1. In my case I will install 2.7.11 as it's the recommended version from Python. You can get the latest installer from here. Once the setup is completed you will have to reboot your machine to make sure the configuration is updated.

Downloading PARSE server example.
Head to PARSE server source code on GitHub and download the PARSE server example from here. Unzip the zip file under C:\Parse for example. Once everything is in place, open node.js command prompt with admin rights and run the command npm install under C:\Parse folder:


During the installation I hit a small bump with the following error message:
MSBUILD : error MSB4132: The tools version "2.0" is unrecognized. Available tools versions are "14.0", "4.0".

To overcome this issue, just install the MSBuild Tools from VS2013. This can be found here. Now we are ready to start our PARSE server.

Starting PARSE server.
Remember to start mongoDB first here as the server was restarted from installing Pyhton. MongoDB should show that its waiting for connection. Here are some logs when the system is up and running:

Configure PARSE:
Open the file index.js under C:\Parse and edit the sections appId and masterKey

In my case, I mentioned the appId as 'thunderParse' and the masterKey as a nice key (base64 string).

Run PARSE server via npm:
Once configured, run in the same command line the command npm start.

Now parse is up and running and is ready for requests.

Configuring and Starting PARSE Dashboard.
Now that our PARSE server is running, we can configure and start the PARSE dashboard which is a web base application to manage our PARSE apps.

To get PARSE dashboard, you only need to type the following from npm:

Now we can go to localhost:4040/apps and we will see our application described there:

Testing our self-hosted PARSE server.
Now is the time to test our self-hosted PARSE server. To test it out, we just need to use curl or any other mechanism that we like. I've used curl and Delphi as I already had some libraries prepared for it. Here is the command with curl:
And here with Delphi:

And here are the results of the App writing to Parse server:

Next step is to bring this online and host it somewhere else like Heroku, AWS, AZure or Scalingo.

I hope you find this useful.

Jordi

Testing new Windows 10 components of Delphi 10 Seattle

It's been a while since I got my Delphi 10 Seattle and I really love its new Windows 10 components and styles. I have already played with it and I can say that these new components are really slick and will make your apps really stand out. I've tried the TSplitView and the ActivityIndicator which are great for a full Windows 10 integration. 

Here you can see some screenshots of one of the applications I have created with it and the source code is available on Github:

Initial Screen:

Notice the home button that will control the split view.

Showing the controls:

Controls are hidden/displayed when the home button is pressed. Each of those actions will call each page on the TPageControl component. I'm still looking for a solution where I don't have to show the tabs on the TPagecontrol but I'll get to it later on. I think that as of now, I have a pretty interesting solution that runs fine in my Surface under Windows 10 and it totally looks awesome.

Animation Controls:

I've just added one of the animation controls with a simple processing. There is nothing fancy here, just updating the process regularly would do. If I wanted to make anything better I should put it in a thread for better refresh.

I also tried the TToggleSwitch but it was flickering in runtime so I will report the problem to Embarcadero later on. The new style works really well but I found that the ShBrowseForFolder is not rendering it correctly:

The source code of this little utility can be found here:

• https://github.com/JordiCorbilla/search-replace

Executables can be downloaded here:

• https://app.box.com/s/gww9193ay627xzv3h9h1umrp501qjmzh
• https://github.com/JordiCorbilla/search-replace/releases/download/v1.0/SearchReplace.zip

This small application will allow you to:

• Perform a search on a particular folder and file extension.
• Replace the content of each file for some other content. (really handy when you need to replace a variable in source code files for example).
• Delete the files.
• Also to search empty folders and delete them (really handy when your svn complains about checking in empty folders).

Let me know if you have any questions.

Jordi

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

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:


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.