A sample guide in implementing velocity templates in sending sms and email

2. A template engine is a software development
tool that allows you to create and render
documents that format and present your data
.
A template engine is included as part of
a template system or application
framework
Content from a database and "presentation
specifications" (in a web template), are
combined (through the template engine) to
produce web documents.

3.  Examples are:
Engine Language
Apache Velocity Java, C#
ASP.net C#, VB.net
Casper Java, Javascript
String Template Java, Python
Cheetah Template Python

4.  Template engines generally include features common in
higher level programming with emphasis on processing
plain text
 Features include:
 Variables and functions
 Text replacement
 File inclusion
 Conditional evaluation and loops

5. Velocity Template Engine
It permits the templates to reference methods defined in Java
code using Velocity template language(VTL) statements.
VTL uses references to embed dynamic content in a text
product
References are of three types variables, properties and Methods
VTL REFERENCES
Variable ${aVariable}, $aVariable
Properties ${anIdentifier.aIdentifier}
Methods ${aIdentifier.aMethodBody(${aIdentifier})}

6.  References begin with $ and are used to get something
 Directives begin with # and are used to do something
 #set is used to assign a value to a variable
 The variable, $aVariable can the be used in the template
to output the value(i.e “aValue”)
#set($ aVariable = “aValue”)
Character
directive
Variable
Value

7. Lets Work!!
 Download velocity engine (Velocity-1.7 jar) from
http://velocity.apache.org/download.cgi
 Include the Velocity-1.7 jar jar in the lib folder of your
project folder(you may also have to include commons-
collections.jar, commons-lang and mail.jar).
 Prepare your .vsl template message
 Write your java code

8. Template Message
#*
Test E-mail Message
@zed
*#
Dear Mr $recepientName,
The management of $companyName hereby invite you for an
interview in $interviewVenue at $timeOfInterview .
Yours Sincerely,
$sendersName

9. Sample Code
public void sendMail() {
Template template = null;
template = ve.getTemplate("/myMessage.vsl");
Map<String, String> mymail = new HashMap<String, String>();
mymail.put("recepientName", infoDetail.getRecepientname());
mymail.put("companyName", infoDetail.getCompanyName());
mymail.put("interviewVenue", infoDetail.getInterviewVenue());
mymail.put("timeOfInterview", infoDetail.getTimeOfInterview());
mymail.put("sendersName", infoDetail.getSenderName());
VelocityContext context = new VelocityContext(mymail);
StringWriter writer = writer = new StringWriter();
if (template != null) {
template.merge(context, writer);
}
message = writer.toString();
}

10. Output
Dear Mr James,
The management of Seamfix hereby invite you for an
interview in Lagos at 8:00pm
Yours Sincerely,
Zebrudaya

11. QUESTIONS??