alex-arriaga

alex-arriaga February 15, 2018

How to use the Plugin Otherwise in IBM WCM 8 and 9

The challenge

Imagine you want to run a kind of conditional if with a fallback (else) for example: you would like to have some custom HTML markup when there is no description set on a piece of content. Let’s see following pseudocode:

IF is_There_A_Description(current_Content)
    DISPLAY description
ELSE
    DISPLAY a default text

IF is_There_A_Description(current_Content)

DISPLAY description

ELSE

DISPLAY a default text

So, how could we emulate this behaviour on IBM WCM? Simple…

The solution

Let’s use a server-side solution using the NotEquals plugin, which is really easy to apply, let’s see an example:

[Plugin:NotEquals text1="" text2="[Property context='current' type='content' field='description']"]
	<div class="b-content__description">
               [Property context='current' type='content' field='description']
	</div>
[/Plugin:NotEquals]
[Plugin:Otherwise]<!-- This is our "else" -->
<!-- No description was set, do some custom logic here -->
[/Plugin:Otherwise]

[Plugin:NotEquals text1="" text2="[Property context='current' type='content' field='description']"]

[Property context='current' type='content' field='description']

</div>

[/Plugin:NotEquals]

[Plugin:Otherwise]

[/Plugin:Otherwise]

Explanation

The plugin NotEquals requires two mandatory parameters: text1 and text2 (both strings). In this example, we have text1=”” compared with text2=”[Property context=”current” type=”content” field=”description”].

When WCM renders this HTML with the [Property] meta-tag, it will compare the text2 with text1 and if text2 is not empty, the HTML inside the NotEquals plugin will be rendered, otherwise (else) no HTML will be generated. Simple and elegant.

However… be careful when combining / nesting conditionals:

[Plugin:NotEquals text1="" text2="[Property context='current' type='content' field='description']"]
    [Plugin:NotEquals text1="generic-description" text2="[Property context='current' type='content' field='description']"]
	<div class="b-content__description">
               [Property context='current' type='content' field='description']
	</div>
    [/Plugin:NotEquals]
[/Plugin:NotEquals]
[Plugin:Otherwise]<!-- This is our "else" -->
<!-- No description was set, do some custom logic here -->
[/Plugin:Otherwise]

[Plugin:NotEquals text1="" text2="[Property context='current' type='content' field='description']"]

[Plugin:NotEquals text1="generic-description" text2="[Property context='current' type='content' field='description']"]

[Property context='current' type='content' field='description']

</div>

[/Plugin:NotEquals]

[Plugin:Otherwise]

[/Plugin:Otherwise]

Previous conditional will not work, since the Otherwise plugin is not going to know under which context should act.

IBM provides a way to solve this using what is is called scope. Let’s change a bit our code to set this scope parameter in BOTH NotEquals and Otherwise plugins.

[Plugin:NotEquals text1="" text2="[Property context='current' type='content' field='description']" scope="1"]
    [Plugin:NotEquals text1="generic-description" text2="[Property context='current' type='content' field='description']" scope="2"]
	<div class="b-content__description">
               [Property context='current' type='content' field='description']
	</div>
    [/Plugin:NotEquals]
[/Plugin:NotEquals]
[Plugin:Otherwise scope="1"]<!-- This is our "else" with scope="1" which means, it will act with the first NotEquals plugin -->
<!-- No description was set, do some custom logic here -->
[/Plugin:Otherwise]

[Plugin:NotEquals text1="" text2="[Property context='current' type='content' field='description']" scope="1"]

[Plugin:NotEquals text1="generic-description" text2="[Property context='current' type='content' field='description']" scope="2"]

[Property context='current' type='content' field='description']

</div>

[/Plugin:NotEquals]

[Plugin:Otherwise scope="1"]

[/Plugin:Otherwise]

Otherwise plugin restrictions

The Otherwise plugin ONLY works with:

Equals plug-in
NotEquals plug-in
Matches plug-in

I hope you find this information useful, and remember, be happy with your code!

alex-arriaga March 12, 2017

Installing a Node.js App as a regular GNU/Linux process

GNU/Linux, Node.js, Operating Systems No Reply

While in development of any Node.js application we usually configure a npm start task to run it; but when you are ready to go to production that concept is not useful anymore. Until that moment, we have tested our application using the regular npm process (npm start); but now, we are going to need to go one step further. We will install a process manager for Node.js called PM2: http://pm2.keymetrics.io/.

PM2 will allow us to register our Node.js application as a regular process in GNU/Linux.

1) Install PM2:

sudo npm install pm2 -g

1	sudo npm install pm2 -g

2) Run pm2 start command to run the application:

// This also adds the application to PM2's process list, 
// which is outputted every time you start an application
sudo pm2 start /path/to/main/nodejs/script

// For example:
sudo pm2 start /usr/share/nginx/html/wetraining-chat/server.js

// This also adds the application to PM2's process list,

// which is outputted every time you start an application

sudo pm2 start /path/to/main/nodejs/script

// For example:

sudo pm2 start /usr/share/nginx/html/wetraining-chat/server.js

Figure 1. Example of server process in PM2.

PM2 automatically assigns an Application name and a PM2 id. In this case since the file is “server.js”; the resulting process would be “server”. PM2 also maintains other information, such as the PID of the process, its current status, and memory usage.

Applications running under PM2 will be restarted automatically if the application crashes or is killed, but an additional step needs to be taken to get the application to launch on system startup (boot or reboot). To solve this, PM2 provides the startup subcommand.

The startup subcommand generates and configures a startup script to launch PM2 and its managed processes on server boots. You must also specify the platform you are running on, which is ubuntu, in our case:

sudo pm2 startup ubuntu

1	sudo pm2 startup ubuntu

Useful PM2 commands

// Stop the application
pm2 stop APP_NAME
  
// Restart an application
sudo pm2 restart APP_NAME
  
// List the applications currently managed by PM2
sudo pm2 list
  
// Get meta-data about an application
sudo pm2 info APP_NAME
  
// Display the application status, CPU, and memory usage
sudo pm2 monit

// Stop the application

pm2 stop APP_NAME

// Restart an application

sudo pm2 restart APP_NAME

// List the applications currently managed by PM2

sudo pm2 list

// Get meta-data about an application

sudo pm2 info APP_NAME

// Display the application status, CPU, and memory usage

sudo pm2 monit

I hope you find this information useful. PM2 is an excellent option to register our Node.js app as regular GNU/Linux. There are other options out there like Strong Loop Process Manager and Forever. Have you used one of them? Let me know your opinion.

alex-arriaga September 27, 2016

Learning Functional Programming with JavaScript – JSUnconf 2016

JavaScript, Web Development 2 Replies

Functional Programming? Oh yeah, that is one of the most interesting paradigms in computer sciences that is being used since a long time ago, however in the last years it has obtained a particular interest because of JavaScript, in fact, I bet you are being using functional programming without even know it.

In this great conference by Anjana Vakil you will learn the fundamentals of this paradigm as well as some examples using the JavaScript language.

As a complement to this conference here is an awesome article called “A practical introduction to functional programming by Mary Rose Cook”

alex-arriaga August 18, 2016

Delete files with a pattern recursively using the terminal

GNU/Linux, Mac OSX, Operating Systems No Reply

This is just a simple way to delete files recursively using your terminal in any UNIX-like operating system:

find . -type f -name "FILES_PATTERN" -exec rm {} \;

// Example
find . -type f -name "*.mp3" -exec rm {} \;

find . -type f -name "FILES_PATTERN" -exec rm {} \;

// Example

find . -type f -name "*.mp3" -exec rm {} \;

Explanation

-name “FILES_PATTERN” : File pattern.
-exec rm -rf {} \; : Delete all files that match the file pattern.
-type f : Not include directories.

alex-arriaga August 18, 2016

How to know if a user is authenticated or not in WCM 8 and 8.5

Enterprise Development, IBM Web Content Manager No Reply

This is pretty simple way to check if any user has a session started or not; this is useful in cases where you want to display or execute an specific code depending on the user session. To create this kind of validation we can take advantage of the WCM plugins Equals and NotEquals

[Plugin:Equals text1="true" text2="[Plugin:RequestAttribute key='userLoggedIn' mode='get']"]
<!-- Authenticated block -->
<p class="authenticated">I have a session.</p>
[/Plugin:Equals]

[Plugin:NotEquals text1="true" text2="[Plugin:RequestAttribute key='userLoggedIn' mode='get']"]
<!-- Not authenticated block -->
<p class="anonymous">I DON'T have a session.</p>
[/Plugin:NotEquals]

[Plugin:Equals text1="true" text2="[Plugin:RequestAttribute key='userLoggedIn' mode='get']"]

<p class="authenticated">I have a session.</p>

[/Plugin:Equals]

[Plugin:NotEquals text1="true" text2="[Plugin:RequestAttribute key='userLoggedIn' mode='get']"]

<p class="anonymous">I DON'T have a session.</p>

[/Plugin:NotEquals]

alex-arriaga August 18, 2016

Update Node.js using the terminal

GNU/Linux, Mac OSX, Node.js No Reply

These are just the steps to update Node.js by using your terminal:

sudo npm cache clean -f
sudo npm install -g n

1 2	sudo npm cache clean -f sudo npm install -g n

The n package represents a Node helper, and running this command upgrades node to the latest stable version.

sudo n stable

1	sudo n stable

Just to confirm we can check our version:

node -v

// Output
v6.3.1

node -v

// Output

v6.3.1

alex-arriaga May 2, 2016

Uncommon Sense by Derek Sivers

Serendipity No Reply

A great talk about how a business can evolve, from being just an idea to become a millionaire business.

If you have an amazing idea but no execution, it’s not worth anything. You haven’t done anything. It’s worthless.

If you had a good idea and you’ve actually gone and made it happen in a pretty good way, you could maybe make a million dollars. And if you have an amazing idea, and you have an amazing team and you do great execution, you could maybe make 20 million dollars.

Derek Sivers in Uncommon Sense – live @ WDS

alex-arriaga May 2, 2016

Inventing on Principle by Bret Victor

Serendipity, Web Development No Reply

If you are a person who believes web development is not only solving problems in the best way but creating new ways of thinking while having compassion for others, then this talk is for you; 54 minutes about a different way to see why ideas are one of most important things humans can create.

alex-arriaga April 19, 2016

Logging detailed error messages when running Gulp.js tasks

Gulp.js, JavaScript, Node.js No Reply

Gulp.js has become one of the most used task managers nowadays. But sometimes, when running several tasks with many pipes( ) on them, it is very difficult to understand what’s wrong or the actual reason why our task is not working as expected. For others like me, who like to have a better error description, here is what needed to do:

Install Gulp Util

npm install —save-dev gulp-util

1	npm install —save-dev gulp-util

Import the Gulp Util by using the following statement:

var gutil = require('gulp-util');

1	var gutil = require('gulp-util');

Finally, in your pipes, add a new “event” to manage the “error”, e.g. when you are uglifying your code, here is how you can attach the error handler of gulp util:

.pipe(uglify().on('error', gutil.log))

1	.pipe(uglify().on('error', gutil.log))

Notice the “on(‘error’)” part, that is where the magic happens.

Hope you find this top useful, see you next time!

What would you like to know about?

Alex Arriaga

All posts by
alex-arriaga

How to use the Plugin Otherwise in IBM WCM 8 and 9

The challenge

The solution

Explanation

Otherwise plugin restrictions

Installing a Node.js App as a regular GNU/Linux process

Useful PM2 commands

Learning Functional Programming with JavaScript – JSUnconf 2016

Delete files with a pattern recursively using the terminal

Explanation

How to know if a user is authenticated or not in WCM 8 and 8.5

Update Node.js using the terminal

Uncommon Sense by Derek Sivers

Inventing on Principle by Bret Victor

Logging detailed error messages when running Gulp.js tasks

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Otherwise plugin restrictions

Useful PM2 commands

Explanation

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