July 2013 – Alex Arriaga

alex-arriaga July 25, 2013

How to find and see all unread messages in Gmail and more…

Today, I was trying to get a list of all my unread messages in Gmail, at the beginning I thought this task it would be really easy, but actually, took me more than 15 minutes to find the correct way to do it (thanks to my Base22 friends, because they told me how do it). For this reason I would like to share the easiest way to filter your messages. Well, search in gmail is be able to take “complex parameters” to say what we need.

For example if I want to get all unread messages only I will need to type next “command” inside of the search box in gmail:

is:unread

is:unread

As you can see, it is possible to use other options in your search, see next examples:

is:inbox
is:starred
is:read
l:^u
label:unread

is:inbox

is:starred

is:read

l:^u

label:unread

These are some more complex queries (remove quotes in your queries, they are not necessary):

"l:^u from:alex" finds all unread messages from "alex"
"l:^u l:^t" finds all unread starred mail
"l:^u l:^k subject:certification" finds all unread messages with "certification" in the subject that are in the Trash

"l:^u from:alex" finds all unread messages from "alex"

"l:^u l:^t" finds all unread starred mail

"l:^u l:^k subject:certification" finds all unread messages with "certification" in the subject that are in the Trash

That’s it!

UPDATE: Thanks to Cody Burlenson for sharing this complete list of options for Advanced Search in gmail: https://support.google.com/mail/answer/7190?hl=en

Be happy with your mail 🙂

—

Alex Arriaga

alex-arriaga July 23, 2013

How to set directory and files permissions for a Joomla site in a production environment

GNU/Linux, Joomla, Operating Systems, Web Development 2 Replies

When you have a project created on Joomla CMS, you will need to protect your directories and files in order to avoid a possible attack or loosing information. During my time as a web developer and as a server admin in Government I learnt about what’s is a good configuration for setting permissions, for this reason I would like to share a list of commands that you can use in your own server. This set of commands apply to a GNU/Linux or UNIX-like operating systems, obviously I don’t recommend use IIS from Microsoft (I am sorry Microsoft, but PHP + IIS is NOT a good option).

In a nutshell, you can use these commands:

find /YOUR_SERVER_PATH/YOUR_ROOT_JOOMLA_DIRECTORY -type f -print0 | xargs -0 chmod 644
find /YOUR_SERVER_PATH/YOUR_ROOT_JOOMLA_DIRECTORY -type d -print0 | xargs -0 chmod 755
chmod -R g+w /YOUR_SERVER_PATH/YOUR_ROOT_JOOMLA_DIRECTORY/images
chmod -R g+w /YOUR_SERVER_PATH/YOUR_ROOT_JOOMLA_DIRECTORY/cache
chmod -R g+w /YOUR_SERVER_PATH/YOUR_ROOT_JOOMLA_DIRECTORY/tmp

find /YOUR_SERVER_PATH/YOUR_ROOT_JOOMLA_DIRECTORY -type f -print0 | xargs -0 chmod 644

find /YOUR_SERVER_PATH/YOUR_ROOT_JOOMLA_DIRECTORY -type d -print0 | xargs -0 chmod 755

chmod -R g+w /YOUR_SERVER_PATH/YOUR_ROOT_JOOMLA_DIRECTORY/images

chmod -R g+w /YOUR_SERVER_PATH/YOUR_ROOT_JOOMLA_DIRECTORY/cache

chmod -R g+w /YOUR_SERVER_PATH/YOUR_ROOT_JOOMLA_DIRECTORY/tmp

For example, if my SERVER_PATH is something like this: /var/www/ and my ROOT_JOOMLA_DIRECTORY is digital-newspaper, then we can use this commands:

# This line sets all files inside of digital-newspaper to "644" permissions
find /var/www/digital-newspaper -type f -print0 | xargs -0 chmod 644

# Setting all directories to "755"
find /var/www/digital-newspaper -type d -print0 | xargs -0 chmod 755

# Special group permissions are necessary in images, cache and tmp directories
chmod -R g+w /var/www/digital-newspaper/images
chmod -R g+w /var/www/digital-newspaper/cache
chmod -R g+w /var/www/digital-newspaper/tmp

# This line sets all files inside of digital-newspaper to "644" permissions

find /var/www/digital-newspaper -type f -print0 | xargs -0 chmod 644

# Setting all directories to "755"

find /var/www/digital-newspaper -type d -print0 | xargs -0 chmod 755

# Special group permissions are necessary in images, cache and tmp directories

chmod -R g+w /var/www/digital-newspaper/images

chmod -R g+w /var/www/digital-newspaper/cache

chmod -R g+w /var/www/digital-newspaper/tmp

So, that’s it!

Be happy with your servers!

—

Alex Arriaga

alex-arriaga July 23, 2013

Reading an XML file by using Joomla 2.5 API – JFactory::getXML()

Joomla, PHP, Uncategorized, Web Development 2 Replies

Imagine the situation where you need to read a list of configuration permissions, these permissions are inside of an XML file called permisos.xml in a valid directory of your server. In this short article we will see how to read an XML file, parse it and create an array with all entries of this file. There are several ways to do this, but we will use the compatible option with Joomla 2.5 API, why? well, because Joomla 2.5 is the stable and recommended version -currently- of this CMS (Content Management System). So, please let me show you how to complete this task.

Next is a valid XML file:

<?xml version="1.0" encoding="utf-8"?>
<permisos>
   <grupo id="8" nombre="Administrators">
         <modulo nombre="COM_ADMIN_ORDER_MOD" visible="true">
            <menu nombre="COM_ORDER_S" visible="true"></menu>
            <menu nombre="COM_REPORT" visible="true"></menu>
            <menu nombre="COM_USER_S" visible="true"></menu>
            <menu nombre="COM_SHOPPERGROUP_S" visible="true"></menu>
            <menu nombre="COM_COUPON_S" visible="true"></menu>
         </modulo>
   </grupo>
 	<grupo id="11" nombre="Team Members">
   		<modulo nombre="COM_ADMIN_ORDER_MOD" visible="false">
   			<menu nombre="COM_ORDER_S" visible="false"></menu>
   			<menu nombre="COM_REPORT" visible="true"></menu>
   			<menu nombre="COM_USER_S" visible="false"></menu>
   			<menu nombre="COM_SHOPPERGROUP_S" visible="false"></menu>
   			<menu nombre="COM_COUPON_S" visible="false"></menu>
   		</modulo>
	</grupo>
</permisos>

<?xml version="1.0" encoding="utf-8"?>

</modulo>

</grupo>

</modulo>

</grupo>

</permisos>

Now, with this simple code we can read all this file using Joomla 2.5 classes and methods, in particular we will use the static method getXML() from JFactory.

$usuario =& JFactory::getUser();
$grupos_usuario = $usuario->groups;
$permisos = array();

	// Reading file
	$xmlfile = JURI::base().'/some_path/permisos.xml';
	$xml = JFactory::getXML($xmlfile,true);

	foreach($xml->children() as $grupo):
		$id_grupo_xml = $grupo->getAttribute("id");
		foreach($grupo->children() as $modulo):
			// Permissions by module
			foreach($grupos_usuario as $id_grupo):
				if(in_array($id_grupo_xml, $grupos_usuario))
					$permisos[$id_grupo][$modulo->getAttribute("nombre")] = $modulo->getAttribute("visible");
			endforeach;

			// Permissions for each menu entry in every one of the modules
			foreach($modulo->children() as $menu):
				foreach($grupos_usuario as $id_grupo):
					if(in_array($id_grupo_xml, $grupos_usuario))
						$permisos[$id_grupo][$menu->getAttribute("nombre")] = $menu->getAttribute("visible");
				endforeach;
			endforeach;
		endforeach;// all modules
	endforeach; // all groups

	echo "<pre>";
		print_r($permisos);
	echo "</pre>";

$usuario =& JFactory::getUser();

$grupos_usuario = $usuario->groups;

$permisos = array();

// Reading file

$xmlfile = JURI::base().'/some_path/permisos.xml';

$xml = JFactory::getXML($xmlfile,true);

foreach($xml->children() as $grupo):

$id_grupo_xml = $grupo->getAttribute("id");

foreach($grupo->children() as $modulo):

// Permissions by module

foreach($grupos_usuario as $id_grupo):

if(in_array($id_grupo_xml, $grupos_usuario))

$permisos[$id_grupo][$modulo->getAttribute("nombre")] = $modulo->getAttribute("visible");

endforeach;

// Permissions for each menu entry in every one of the modules

foreach($modulo->children() as $menu):

foreach($grupos_usuario as $id_grupo):

if(in_array($id_grupo_xml, $grupos_usuario))

$permisos[$id_grupo][$menu->getAttribute("nombre")] = $menu->getAttribute("visible");

endforeach;

endforeach;// all modules

endforeach; // all groups

echo "<pre>";

print_r($permisos);

echo "</pre>";

After reading content of the XML file we will get an output like this:

Array
(
    [8] => Array
        (
            [COM_ADMIN_ORDER_MOD] => true
            [COM_ORDER_S] => true
            [COM_REPORT] => true
            [COM_USER_S] => true
            [COM_SHOPPERGROUP_S] => true
            [COM_COUPON_S] => true
        )

)

Array

(

[8] => Array

(

[COM_ADMIN_ORDER_MOD] => true

[COM_ORDER_S] => true

[COM_REPORT] => true

[COM_USER_S] => true

[COM_SHOPPERGROUP_S] => true

[COM_COUPON_S] => true

)

As you can see, it is really easy to read XML files, if you have some comments about this, please let me know.

Be happy with your code!

—

Alex Arriaga

alex-arriaga July 22, 2013

Validating if a jQuery plugin exists before running code that use it

jQuery, Web Development No Reply

When we are creating plugins or simple code in jQuery and there is a single or many plugin dependences among them, a common task is to implement a mechanism to validate if a jQuery plugin exists before running “depending” code, for example if we have this code and we have not included jqprint (a nice plugin to print a fragment of an HTML document), then an error will appear indicating that jqprint function is undefined.

(function($) {
    $(document).ready(function() {
        $(".print-this-section").on('click', function(){
            $("#section-to-print").jqprint();
        });
    });
})(jQuery);

(function($) {

$(document).ready(function() {

$(".print-this-section").on('click', function(){

$("#section-to-print").jqprint();

});

})(jQuery);

So, in order to solve this “undefined” error we could add a little validation before running jqprint code.

(function($) {
    $(document).ready(function() {
 		if( jQuery().jqprint ){ // Verifying jqprint exists
	        $(".print-this-section").on('click', function(){
	            $("#section-to-print").jqprint();
	        });
		}
    });
})(jQuery);

(function($) {

$(document).ready(function() {

if( jQuery().jqprint ){ // Verifying jqprint exists

$(".print-this-section").on('click', function(){

$("#section-to-print").jqprint();

});

}

});

})(jQuery);

With this simple code, you would be able to avoid errors in your code when a plugin is not defined.

That’s it!

Be happy with your code!

—

Alex Arriaga

alex-arriaga July 17, 2013

How to set expiry date of a cookie (using jQuery Cookies plugin)

jQuery, Web Development 2 Replies

In a previous post I explained what is the process for Saving a complex JSON object in a cookie by using jQuery (demo included in PHP). Now, I would like to add some related information about how to set an expiry date of a cookie using the same plugin (jQuery Cookies).

First of all, it is important to know that an expire date is just a valid JavaScript Date Object, I mean, you will only need to create a date and then assign this to an array of options when you save your data in a cookie. Let me explain using a little example:

function setUserConfigInCookie(){
      var expireDate = new Date;
      expireDate.setDate(expireDate.getDate() + 7); // It expires in a week

      var options = {
        path: '/',
        expiresAt: expireDate
      }

      userConfig = {}; // This is a valid JSON object that you need to save in a cookie
      $.cookies.set( 'userConfig', userConfig, options);

      // console.log('Expires=' + expireDate.toGMTString());
    }

function setUserConfigInCookie(){

var expireDate = new Date;

expireDate.setDate(expireDate.getDate() + 7); // It expires in a week

var options = {

path: '/',

expiresAt: expireDate

}

userConfig = {}; // This is a valid JSON object that you need to save in a cookie

$.cookies.set( 'userConfig', userConfig, options);

// console.log('Expires=' + expireDate.toGMTString());

}

With this simple code we can save a cookie (complex JSON object) and set an expiry date (in this example the cookie is going to expire in a week). If you want to verify that all is working, you could search for your cookie in your favorite browser, for example next image uses Firefox to see this cookie:

That’s it at this moment.

Be happy with your code!

—

Alex Arriaga

alex-arriaga July 16, 2013

How the world ends:

Serendipity 2 Replies

“A woman tells her programmer husband to go to the store for some milk and while he’s there, get some eggs. He takes egg carton after egg carton, until there are none left. He reaches for empty space. The ground splits beneath his feet. The universe trembles and collapses.

This is how the world ends. Not with a bang but with a Null Pointer Exception”

— Thank to the profound programmer

“The human brain is programmed with fuzzy logic even if the above scenario did happen, the programmer would simply collapse (the universe for him go dark), pass out (shut down) and then wake up (reboot) thankfully, human existance is sandboxed and multithreaded. We can kill that thread without any dependancies or repercussions (other than the obvious legal, social, moral, and religious (if they apply)).

Also the guilt…oh god the guilt. But no physical or logical repercussions that endanger the fabric of existence”

— Thank to Ben Shoemate

—

Alex Arriaga

alex-arriaga July 16, 2013

How to use and understand Binary Search on Java SE

Enterprise Development, Java EE 2 Replies

Java is a Platform to create robust, secure and scalable stand-alone and enterprise web applications. It has a lot of classes and resources that make easy to develop many functionalities in systems. One of the most interesting parts of the Java API (Application Programming interface) is work with collections and generics. Basically, Java has three kinds of “collections”: Set, List and Map (this one is not necessarily a collection but it is enough alike than one, so its use doesn’t cause any problem, if we understand how collections work).

Well, in Java there is a special static class called Arrays (java.util.Arrays),

This class contains various methods for manipulating arrays (such as sorting and searching). This class also contains a static factory that allows arrays to be viewed as lists.

Today, I would like to show you how to use a method that implements Binary Search, but before we could check the official information about this method:

Binary Search method. Searches the specified array of ints for the specified value using the binary search algorithm. The array must be sorted (as by the sort(int[]) method) prior to making this call. If it is not sorted, the results are undefined. If the array contains multiple elements with the specified value, there is no guarantee which one will be found.

This method has a lot of overrides, for more information about them, please visit: http://docs.oracle.com/javase/6/docs/api/java/util/Arrays.html#binarySearch(java.lang.Object[], java.lang.Object)

Now, imagine that we have the next code:

import java.util.*;

public class ArraysTest{
	public static void main(String [] args) {
		String [] colors = {"blue", "red", "green", "yellow", "orange"};

		// It is necessary to have an ordered array
		Arrays.sort(colors);
		for(String color : colors)
			System.out.print(color + " ");

		int index1 = Arrays.binarySearch(colors, "orange");
		int index2 = Arrays.binarySearch(colors, "violet");
		System.out.println("\norange => " + index1);
		System.out.println("violet => " + index2);
	}
}

import java.util.*;

public class ArraysTest{

public static void main(String [] args) {

String [] colors = {"blue", "red", "green", "yellow", "orange"};

// It is necessary to have an ordered array

Arrays.sort(colors);

for(String color : colors)

System.out.print(color + " ");

int index1 = Arrays.binarySearch(colors, "orange");

int index2 = Arrays.binarySearch(colors, "violet");

System.out.println("\norange => " + index1);

System.out.println("violet => " + index2);

}

The output is something like this:

blue green orange red yellow
orange => 2
violet => -5

blue green orange red yellow

orange => 2

violet => -5

According to the API:

Parameters:
- a – the array to be searched
- key – the value to be searched for
Returns:
- index of the search key, if it is contained in the array; otherwise, (-(insertion point) – 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element greater than the key, or a.length if all elements in the array are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.
Throws:
- ClassCastException – if the search key is not comparable to the elements of the array.

Explanation

The first result after searching for “orange” is clear because “orange” was found in the index: 2.

Second result is a little more complex. Let me ask you, was “violet” found in the array? what should the index where “violet” be inserted? Well, see next image to understand better:

As you can see index:4 is where “violet” should be inserted. For this reason binarySearch return -5 (see next operation for more details):

-(insertion point) - 1 = -(4) -1 = -5

1	-(insertion point) - 1 = -(4) -1 = -5

That’s it, at this moment.

Be happy with your code!

—

Alex Arriaga

alex-arriaga July 10, 2013

Saving a complex JSON object in a cookie by using jQuery (demo included in PHP)

jQuery, Web Development 8 Replies

Today, I spent almost three hours to test and implement a mechanism to save a complex JSON object and get it to render in a HTML output,, for this reason I would like to explain what was the ~~best~~ easiest way that I found for saving my object.

First, I would recommend you to be sure that your object is well-created, I mean, it is important that your JSON object is according to JavaScript Object Notation (you can visit this link to read more about: http://www.json.org/).

Second, I have used some compatible plugins with jQuery (I have tested this plugins using jQuery 1.8.2, this because in my project jQuery had already existed, also I have tested in jQuery 1.10.2), In a nutshell, we need the next JavaScript files:

Creating our complex JSON object

I have decided to use PHP to create our testing object (because most of developers have knowledge in this programming language).

// An array to simulate a complex JSON object
		$userSettings =  array(
			"personal_information" => array(
				"name" => "Alex",
				"last_name" => "Arriaga"
				),
			"extra_information" => array(
				"twitter" => "alex_arriaga_m",
				"facebook" => "alex.arriaga.m",
				"website" => "http://www.alex-arriaga.com/",
				"programming_languages" => array("HTML5", "CSS3", "JavaScript", "PHP", "Java", "C# .NET", "AWK", "LESS", "XML")
			)
		);

		// Creating the JSON object
		$jsonObject = json_encode($userSettings);

// An array to simulate a complex JSON object

$userSettings = array(

"personal_information" => array(

"name" => "Alex",

"last_name" => "Arriaga"

"extra_information" => array(

"twitter" => "alex_arriaga_m",

"facebook" => "alex.arriaga.m",

"website" => "http://www.alex-arriaga.com/",

"programming_languages" => array("HTML5", "CSS3", "JavaScript", "PHP", "Java", "C# .NET", "AWK", "LESS", "XML")

)

);

// Creating the JSON object

$jsonObject = json_encode($userSettings);

Saving and getting our complex JSON object

Now, we can create a simple JavaScript code to save our JSON object and get it later.

	(function($){
		$(document).on('ready', function(){
			//A cookie by the name 'userSettings' now exists with a serialized copy of $userSettings
			$.cookies.set( 'userSettings', <?php echo $jsonObject; ?> );

			//A variable named 'userSettings' now holds the unserialized object, it should be identical to the PHP variable 'userSettings'
			var userSettings = $.cookies.get( 'userSettings' );

			// Do something with the values read from cookie
			console.log(userSettings);
		});
	})(jQuery);

(function($){

$(document).on('ready', function(){

//A cookie by the name 'userSettings' now exists with a serialized copy of $userSettings

$.cookies.set( 'userSettings', <?php echo $jsonObject; ?> );

//A variable named 'userSettings' now holds the unserialized object, it should be identical to the PHP variable 'userSettings'

var userSettings = $.cookies.get( 'userSettings' );

// Do something with the values read from cookie

console.log(userSettings);

});

})(jQuery);

Verifying result

To see the saved object please use Firebug (in cookie tab). See next images like a demo of this.

Figure 1. Saving JSON object

Figure 2. Getting JSON object and verifying in Firebug console

It is possible to configure several parameters, but I think is better for you read them in the official github page of this plugin: https://code.google.com/p/cookies/

You can download this example code for testing more parameters or personalize according to your project. Download here.

That’s it. Be happy with your code!

—

Alex Arriaga

alex-arriaga July 10, 2013

How to trim or delete trailing white spaces automatically on save in Sublime Text 2

Mac OSX, Operating Systems, Web Development No Reply

Sublime Text 2 is my opinion one of most beautiful and useful editors for web developers, of course I really like Notepad++ (but this one, it doesn’t have a version for MAC OSX). A common task when we are creating awesome source codes is trim/delete trailing white spaces, because these are not good and even they could bring on some issues in programming. So, if you want to do this automatically when you save your files and you are using Sublime Text 2, then is really easy, please just:

1) Click on: Sublime Text 2 > Preferences > Settings – User

2) This will open a file with a JSON format configuration.

3) Add the next configuration parameter to your Sublime Text 2:

"trim_trailing_white_space_on_save" : true

1	"trim_trailing_white_space_on_save" : true

In my case my configuration file looks like this:

{
	"color_scheme": "Packages/Color Scheme - Default/Eiffel.tmTheme",
	"font_size": 14.0,
	"ignored_packages":
	[
		"Vintage"
	],
	"trim_trailing_white_space_on_save" : true
}

{

"color_scheme": "Packages/Color Scheme - Default/Eiffel.tmTheme",

"font_size": 14.0,

"ignored_packages":

[

"Vintage"

"trim_trailing_white_space_on_save" : true

}

Note: It is important the comma “,” before the line “trim_trailing_white_space_on_save” : true in order to avoid error in your configuration file.

For Windows users

I think, Sublime Text 2 – Windows version has an alike option, please look for this and follow the same procedure.

That’s it. Be happy with your code!

—

Alex Arriaga

alex-arriaga July 10, 2013

How to find blank lines in a set of files in GNU/Linux or UNIX-Like Operating Systems

GNU/Linux, Mac OSX, Operating Systems No Reply

This short script could help you find blank lines at the beginning or the end of a set of files (in this case in the same directory where you run this script).

for f in `find . -type f`; do 
  for t in head tail; do 
    $t -1 $f  |egrep '^[  ]*$' >/dev/null && echo "blank line at the $t of $f"; 
  done; 
done

for f in `find . -type f`; do

for t in head tail; do

$t -1 $f |egrep '^[ ]*$' >/dev/null && echo "blank line at the $t of $f";

done;

done

To run this command:

1) Open your terminal (en GNU/Linux or UNIX-Like OS, it doesn’t work in any Microsoft Windows OS).

2) You can copy and paste the command or if you prefer put it in a single line, go ahead the command also will work!

for f in `find . -type f`; do for t in head tail; do $t -1 $f  |egrep '^[  ]*$' >/dev/null && echo "blank line at the $t of $f"; done; done

1	for f in `find . -type f`; do for t in head tail; do $t -1 $f \|egrep '^[ ]*$' >/dev/null && echo "blank line at the $t of $f"; done; done

Thanks to the original post in stackoverflow: http://stackoverflow.com/questions/1943727/find-all-files-with-blank-or-ws-at-bof-or-eof

That’s it. Be happy with your code!

—

Alex Arriaga

What would you like to know about?

Alex Arriaga

Monthly Archives:
July 2013

How to find and see all unread messages in Gmail and more…

How to set directory and files permissions for a Joomla site in a production environment

Reading an XML file by using Joomla 2.5 API – JFactory::getXML()

Validating if a jQuery plugin exists before running code that use it

How to set expiry date of a cookie (using jQuery Cookies plugin)

How the world ends:

How to use and understand Binary Search on Java SE

Saving a complex JSON object in a cookie by using jQuery (demo included in PHP)

How to trim or delete trailing white spaces automatically on save in Sublime Text 2

How to find blank lines in a set of files in GNU/Linux or UNIX-Like Operating Systems

Join me, have fun and learn!

Recent Posts

Recent Comments

Join me, have fun and learn!

Recent Posts

Day quote…

Recent Comments

Categories

Archives

Join me, have fun and learn!

Recent Posts

Archives

Recent Comments

Categories

What would you like to know about?

Monthly Archives: July 2013

Join me, have fun and learn!

Tag Cloud

Recent Posts

Recent Comments

Join me, have fun and learn!

Recent Posts

Day quote…

Recent Comments

Categories

Tag Cloud

Archives

Join me, have fun and learn!

Recent Posts

Archives

Tag Cloud

Recent Comments

Categories

Monthly Archives:
July 2013