MONAD: A Model Driven Software Product Line to Create Domain

Speciﬁc Websites

Juan David Villa, Jaime Chavarriaga and Rubby Casallas

Grupo de Construcci

on de Software, Universidad de los Andes, Bogot

a, Colombia

Keywords:

Model Driven Web Engineering, Web Content Management Systems, Templates.

Abstract:

Websites in a speciﬁc domain, i.e., restaurants or product catalogs, share various commonalities. Besides

the vocabulary, they can share aspects such as sitemap structure or presentation elements. Web development

companies can take advantage of these commonalities to create reusable assets, in the process of website

construction. We present MONAD, a software product line to efﬁciently build websites for speciﬁc business

domains. MONAD introduces the concept of Domain Template, an asset intended to parametrize websites

in terms of their speciﬁc domain concepts. Using model-driven techniques, domain templates allow users

to reuse presentation elements, sitemap and pages structures, and automate the insertion of content into a

particular website. Domain templates are implemented using platform independent models; therefore they can

be used to create websites on different web content management systems, i.e., Joomla! or wiki systems.

1 INTRODUCTION

To build a website, a company must design the web-

site’s visual appearance, deﬁne its content and ﬁnally

create the individual pages. Even when wikis or

WCMS are used as platforms to build the website in

a more ﬂexible and manageable way, these tasks are

still time consuming and the resulting presentation,

sitemap, content and structure are highly coupled.

As a result, Graphical design companies, such as

TemplateMonster and Allwebco, offer presentation

templates to reuse graphic designs. Hosting compa-

nies such as Google Sites and Weebly offer templates

that in addition to the graphic design, include as well

sitemaps and sample pages facilitating the reuse of

predesigned website structures for a speciﬁc business

domain.

However, a current limitation of templates is that

website creators manually customize the template by

modifying the predeﬁned structures and manually in-

sert the concrete data of the website into the template.

Furthermore, the customized templates are speciﬁc to

a platform and cannot be used with other technologies

or hosting providers.

(Martinez et al., 2009), (Souer et al., 2011) have

proposed the creation of software product lines to im-

plement websites in a more efﬁcient and effective

manner. Our work is in the same track but it pro-

poses a different approach to build the product line.

Our main contributions are the diverse conﬁguration

possibilities to create concrete websites.

The rest of this paper is organized as follows. Sec-

tion 2 presents related work on website creation ap-

proaches. Section 3 presents MONAD, our model

driven product line approach to create websites on the

same domain. And section 4 presents conclusions and

further work.

2 RELATED WORK

There are several model driven web engineering

(MDWE) approaches that propose the use of mod-

els to generate database-based web applications using

platforms such as Java or PHP. In general terms, these

approaches: (1) separate concerns in diverse platform

independent models, (2) deﬁne a strategy to integrate

them, and (3) transform them into platform speciﬁc

models to ﬁnally produce the code. (Moreno et al.,

2008)

There are fewer works in the case of model-

driven approaches for building websites on Web Con-

tent Management Systems (WCMS) such as Wikis,

Joomla! or Wordpress. The current approaches take

inspiration from the MDWE works.

There are at least two major challenges for these

approaches: 1) Populate a website from existing busi-

ness domain data. 2) Decouple the website from

Villa J., Chavarriaga J. and Casallas R..

MONAD: A Model Driven Software Product Line to Create Domain Speciﬁc Websites.

DOI: 10.5220/0004368400870092

In Proceedings of the 9th International Conference on Web Information Systems and Technologies (WEBIST-2013), pages 87-92

ISBN: 978-989-8565-54-9

 2013 SCITEPRESS (Science and Technology Publications, Lda.)

an speciﬁc WCMS. For the ﬁrst challenge, (D

ıaz

et al., 2011) propose a solution to harvest models from

databases. For the latter, (Souer et al., 2011) propose

the creation of a website platform independent model

and then, a transformation to an speciﬁc WCMS. As

a business domain model is not used in this approach,

the insertion of the content in the website is not cov-

ered, requiring a manual process once the website has

been deployed into a WCMS platform.

(Diaz and Martin, 2009) deﬁne a domain model

and using transformation rules, generate a website

Platform Speciﬁc Model (PSM). Because platform-

speciﬁc models are used, websites are not generated

on different platforms. Additionally, the structure and

presentation elements are speciﬁed inside the trans-

formation’s rules. When a different structure for the

website is needed, a web designer must deﬁne new

transformation rules resulting in difﬁcult changes to

be implemented.

The strategy of creating a model driven product

line is present in (Martinez et al., 2009) (Souer et al.,

2011). We follow the same track but, as we show

in the next section, our approach is different to theirs

in the way we build the assets of the product line

during domain engineering and in the way we de-

rive a concrete website during application engineer-

ing. The main contribution of our work is the diverse

conﬁguration possibilities that we provide to the web-

site creator. These include the ﬂexibility of choosing

the structure of the website, the presentation and the

WCMS platform.

3 MONAD

Our framework presented in Figure 1, is a model

driven software product line (MD-SPL) used to gen-

erate websites. This SPL uses a set of model-based

assets to generate websites supporting variability on

structure, presentation and the WCMS platform.

MONAD deﬁnes two main processes for an SPL:

(1) Domain Engineering, where the domain expert

and website designer deﬁne the website’s variability

and the assets that allow to implement it, creating el-

ements 1, 2, and 3 of ﬁgure 1; and (2) Application

Engineering, where a website creator deﬁnes a busi-

ness domain model and conﬁgures the variability to

derive a set of websites using the assets deﬁned in the

domain engineering, performing steps 4, 5 and 6 of

ﬁgure 1.

To illustrate the processes for domain and applica-

tion engineering in MONAD, we present an SPL for

generating websites for product catalogs. This case

study was introduced by (Diaz and Martin, 2009) to

illustrate model-driven website generation. We ex-

tend the case study to include website variability and

present our approach.

MONAD supports three types of variability: (1)

website structure, (2) website presentation, and (3)

WCMS platform.

Variability on website structure refers to possible

variations in the general structure of the website (i.e.,

the arrangement of the web pages, the types of web

pages, and the content to be included in each type of

web page). For instance, in a product’s catalog web-

site, a way to show the information of the products in

the catalog, is to create for each product a webpage

showing a product’s particular information. On the

other hand, a second option is to display all the prod-

ucts in a single webpage, using a list, where each list

item contains a product’s information.

Variability on website presentation refers to possi-

ble variations in the visual design, mainly by selecting

presentation templates that conﬁgure the icons, colors

and font types of the website.

Variability on WCMS platform refers to possible

WCMS platforms on which MONAD should deploy

the websites.

3.1 Domain Engineering

3.1.1 Building of Website Assets

In MONAD, we introduce a new type of asset called

Domain Template that allows web designers and do-

main experts to deﬁne the website’s structure, specify

the rules of how to generate the content and deﬁne

where to include it in the website structure.

Domain Template. is composed by the following

set of models: (1) a domain-speciﬁc meta-model de-

scribing the vocabulary and elements of the business

domain, (2) a website model specifying the website

structure and the different page elements designed for

this business domain, and (3) a weaving model indi-

cating in which parts of the website model must be

included which elements of the domain.

Business Domain Meta-model. deﬁnes the vocab-

ulary and the elements in the domain. For instance, in

the manufacturing domain, a business domain meta-

model must be deﬁned considering elements such as

catalog, category and product.

During application engineering, for each type of

website, a domain model must be created based on

this meta-model. Figure 2 shows an example meta-

model for product catalogs for manufacturing compa-

nies.

WEBIST2013-9thInternationalConferenceonWebInformationSystemsandTechnologies

Figure 1: MONAD MD-SPL.

Figure 2: Example meta-model for the domain of product

catalogs.

Figure 3: Website metamodel excerpt.

Website Model. describes the website sitemap and

the structure of each webpage. The MONAD frame-

work deﬁnes a meta-model to create these models,

ﬁgure 3 presents an excerpt.

Weaving Model. During domain engineering, a

website designer and a domain expert create a weav-

ing model (Didonet Del Fabro and Valduriez, 2009) to

relate business elements to the website structure. De-

scribed as element 3 in ﬁgure 1, this weaving model

relates a business domain meta-model to a website

model.

Figure 4 shows an overview of a domain template

for a product’s catalog including all the three models.

In the ﬁgure, the dotted arrows represent references

in the weaving model that indicate which elements

in the website model must be created from the ele-

ments of a business domain model. These references

also include information about content that must be

assigned to some attributes in the website elements.

For instance, for each Product in the business do-

main model, a web page must be created including

the name of the product as the title.

In addition, other considerations must be taken

into account when collections are involved in the

weaving. Figure 5 presents an example. The original

website model, website model inside domain template

in ﬁgure 5, is deﬁned with only one product page,

however, when a mapping rule is deﬁned, the source

element can be a collection, in this case the products

of the catalog, view Mapping Rule3.

Therefore, in the ﬁnal website model, sample ﬁnal

website model, there should be a product webpage,

productPage1 and productPage2, for each product in

the domain model, product1 and product2. A calcu-

lated value is used to indicate in the weaving model,

that the source element is a collection. A calculated

value is an OCL query expression. In the case of Map-

pingRule3 the calculated value is the OCL expression

catalog.products.

MONAD’s transformation generator uses the re-

sulting domain template to derive a M2M transforma-

tion. This transformation takes a concrete business

model and produces an independent platform website

MONAD:AModelDrivenSoftwareProductLinetoCreateDomainSpecificWebsites

Figure 4: Domain template example.

Figure 5: Final website model.

Figure 6: ATL rule generated by the Transformation engine.

model with the content from the business model and

the structure from the website model.

Figure 6 shows how MONAD’s transformation

engine uses Mapping rule 1 to create a transforma-

tion rule in the Atlas Transformation language (ATL).

(Jouault et al., 2008) First, it creates an assignment

from the domain model c.name to name, second it cre-

ates an assignment from the original website model

WEBIST2013-9thInternationalConferenceonWebInformationSystemsandTechnologies

’MONAD’ to author and third it merges them into the

ﬁnal rule. Mapping rule 2 is processed in the same

way.

3.2 Application Engineering

3.2.1 Website Conﬁguration

In MONAD, Step 4 in Application Engineering is the

conﬁguration of the structure of the desired website.

In this step, website creators must create a conﬁgura-

tion model with the expected structure for the website.

Currently, MONAD allows customized variations

in the website structure. Instead of using a predeﬁned

domain template, website creators can modify a do-

main template to vary some aspects of the generated

website. In these cases, a new domain template must

be speciﬁed instead of selecting one from the already

deﬁned feature model. This conﬁguration and the do-

main model are taken as input by transformation t1 of

ﬁgure 1.

3.2.2 Website Derivation

After the previous conﬁguration, to derive a website,

two steps are followed. Step 5 is performed by the

website creator who has to provide a business domain

model.

The next step, Step 6 requires the website creator

to conﬁgure the desired website, this includes select-

ing a WCMS (e.g. Joomla! or Wiki systems) and a

visualization template.

transformation t2 is a M2T transformation that

uses (1) the conﬁguration with the target WCMS

and appropriate visual template, and (2) the website

PIM with the corresponding information, generated

by transformation t1, and creates the websites in a

particular WCMS, using the speciﬁc platform API

and databases.

Speciﬁcation of a Business Domain Model. To

generate a speciﬁc website, website creators must

provide a business domain model with the data of the

corresponding company. This model has to be con-

form to the business domain meta-model deﬁned in

the domain engineering. Using Schemol (D

ıaz et al.,

2011), we can derive automatically this business do-

main model from the databases and tables where the

information is stored.

Domain Template Transformations. Using the

domain template, a High Order Transformation

(HOT) (Tisi et al., 2009) is used to create the M2M

transformation of t1 of ﬁgure 1. This transformation

takes a business domain model and a domain tem-

plate, and transforms them into a website PIM with

the corresponding information. This HOT is indepen-

dent of the domain and website metamodels, therefore

the same mechanism can be used for any business do-

main.

WCMS-speciﬁc Transformations. In contrast

with the Domain Template Transformations, there are

a several M2T transformations speciﬁc to a particular

WCMS (described as t2 in ﬁgure 1). MONAD uses

these transformations to deploy the website on the

WCMS platform selected by the website creator.

For instance, to create a website in Joomla, an

M2T transformation is used to generate a script of

SQL commands that uses the proprietary APIs and

databases to store the website content. Then, an

additional tool takes this script and execute them into

the selected Joomla! server to create the website.

Figure 7 presents an example of a product webpage

on Joomla!. In this example, from a website PSM, a

product webpage is generated including the product

picture and an unorder list with some information:

part Id, vendor, title, cost, platform and description.

Figure 7: Generated product webpage in Joomla!

4 CONCLUSIONS

This paper presented MONAD, a strategy and a set of

tools to apply Model-Driven Product Line Engineer-

ing to generate websites for companies in a similar

business domain. These websites can be generated

considering variability on structure, presentation and

WCMS platform. We have presented two case stud-

ies: (1) one that generates websites for product cata-

logs and (2) other that generates websites for faculty

members. The second one has been implemented us-

ing real data and models from a University and it has

been used to continuously improve the approach. In

this case study, there is an initial cost associated to

the domain engineering due to the effort of creating

the weaving model and the domain metamodel. How-

ever, the cost of creating the 134 websites is minimum

MONAD:AModelDrivenSoftwareProductLinetoCreateDomainSpecificWebsites

as the domain model can be populated automatically

using Schemol, and second, the subsequent creation

of the speciﬁc WCMS code is automated by means of

MONAD’s model transformations.

Based on these experiences, we consider that us-

ing MONAD instead of manual coding result in eco-

nomic beneﬁts in scenarios where (1) several web-

sites are created for different companies with a similar

website structure and presentation, (2) when the num-

ber of pages of the same kind in the website is consid-

erable, (3) when the business domain can be automat-

ically generated using mechanisms such as Schemol.

Further work in MONAD includes the addition of

CMS-related concerns such as user proﬁles and per-

missions, platform provided functionality such as fo-

rums, page commentaries and multimedia content.

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