Ousia Weaver - A tool for creating and publishing mashups as impressive Web pages-

Ousia WeaverA tool for creating and publishing mashups

as impressive Web pages

Ikuya Yamada, Wataru Yamaki, Hirotaka Nakajima, Yoshiyasu Takefuji

Studio Ousia Inc.Keio University

3rd Workshop on Mashups, Enterprise Mashupsand Lightweight Composition on the Web (MEM 2010)

Mashup is a technique which combines data and functions from multiple Web sources into new Web contents.

Mashups have become very popular. Numerous mashups have been created on the Web.◦ There are over 4500 mashups registered on

ProgrammableWeb (http://www.programmableweb.com/).

Mashups in a nutshell

http://www.programmableweb.com/

Recently, software tools called “mashup editors” have been attracting attention.◦ Yahoo! Pipes◦ Microsoft Popfly◦ Intel MashMaker

These editors are typically targeted at non-expert users and allow them to create mashups without writing any code.

Mashup Editors

However, existing mashup editors tend to focus only on creating mashups and lack in publishing and visualizing mashups.

If users want to publish mashup results on the Web, they eventually have to do complex programming and/or settings.

Issues

Yahoo! Pipes only supports three simple visualizations (List, Image, Map).

Users cannot customize these visualizations. Pipes doesn’t support publishing its mashups as independent Web

pages.

Example

Visualized mashup result by Yahoo! Pipes

We propose a novel mashup editor named Ousia Weaver.

Ousia Weaver has distinguished functions that strongly support publishing and visualizing mashups.

Ousia Weaver provides a visual editor which enables users to create mashup without writing any code.

Users can create, visualize, and publish mashups without any complex programming and settings.

Ousia Weaver

With Ousia Weaver, users can create mashups using three steps:1. Creating the mashup with Visual Editor2. Visualizing the mashup with Visualization

Widgets3. Publishing the mashup with Mashup Server

Three Steps to Publish Mashups with Ousia Weaver

Creating the mashup

Visualizing the mashup

Publishing the mashup

Creating Mashups

Ousia Weaver provides a visual editor which enables users to create mashups by visually stringing together components.

Mashups are represented using directed graph structure.◦ Operators (nodes) represent data operations.◦ Connections (edges) connect two operators

and define data paths between these.

Programming Model

Connections

Operators

Creating mashup data-

flow



Creating a mashup with Ousia Weaver is an iterative process:◦ Adding desired operators◦ Stringing operators together using

connections.

Mashups are executed in a data-flow manner. 1. InputString operator receives a keyword

from a user.2. AmazonAllByKeyword operator performs a

search on Amazon.com with the keyword.3. OutputItemList operator returns the search

result.

Programming Model

Operators

Connections


flow



The most fundamental component of Ousia Weaver is operators.

Operators represent all data operations in Ousia Weaver.

Currently, Ousia Weaver provides over 300 operators.

An operator consists of input terminals, argument name/value pairs, and output terminals.

OperatorsInput terminal

Argument value

Argument name

Output terminal


flow



All operators can be classified into three groups:

◦ Base operators provide basic programming operations. Arithmetic operation Data type conversion Standard selection operation (If /Switch) Loop operation (While/Foreach)

◦ Data source operators represent Web data sources. Web API Web data extraction (RSS / CSV)

◦ Data transformation operators transform data into a visualizable form. AddImage operator adds thumbnails to the data AddLocation operator attaches geographical locations to the data AddDate and AddDateRange operator add dates and ranges of dates to the

data respectively. AddCoordinate2d operator adds two dimensional coordinates to the data.

Operators

Operators are extensible. Users can add and update arbitrary operators whenever they need.

An operator consists of two files:◦ Simple metadata file (JavaScript)◦ Program code file (Python)

Ousia Weaver provides code templates. Users can create new operators by writing just a few code fragments.

Extending Operators ousiaweaver.Operators.Append = function(){ this.addInputTerminal("string", "Input"); this.addOutputTerminal("string", "Output");}ousiaweaver.Operators.Append.packageName = "base.string";ousiaweaver.Operators.Append.arguments = { "text": { label: "Text", type: "string", required: true, }}

Append.js

class AppendTerminal(OperatorBaseTerminal): def __init__(self,args): OperatorBaseTerminal.__init__(self, args) Input_terminal = {} input_terminal["Input"] = None self.set_input_terminals(input_terminal)class AppendBody(OperatorBaseBody): def __init__(self, args, manager_args, worker): OperatorBaseBody.__init__(self, args, manager_args, worker) def run(self, input_terminals): output_terminals = {} output_terminals["Output"] = str(input_terminals["Input"]) + str(self.get_args()["text"]) return output_terminals

Append.py


flow



Ousia Weaver implements a simple data typing system.

There are some unique data types:◦ any can represent any data

including other data types.◦ itemlist represents a

mashup result and contains multiple item.

◦ data-flow represents a mashup.

Data TypesName Description

any Can represent any data.

string Represents a string.

boolean Represents a boolean.

number Represents a number.

coordinate Represents a coordinate.

datetime Represents a date and a time.

daterange Represents a range of dates.

location Represents a geographical location.

image Represents an image.

uri Represents a URI.

array Represents an array.

object Represents an object (hash-table).

item Represents a constituent of mashup result.

itemlist Represents a mashup result.

data-flow Represents a mashup.Creating

mashup data-flow



A terminal has a data type property.

Two terminals, which have different data type properties, cannot be connected unless either or both properties are any.

When users start dragging one terminal, other terminals will automatically be disabled and turn gray if they cannot be connected with the dragged terminal.

Data Types

Terminals which cannot be connected with the dragged terminal will automatically turn gray.


flow



Visualizing Mashups

With Ousia Weaver, the user can visualize the mashup result by choosing the desired visualization widgets from the list.

Visualizing Mashups

Creating mashup data-flow



Visualization widgets are components which visualize mashup results.◦ Catalog widget ◦ Plot widget◦ Table widget ◦ Map widget◦ Timeline widget

Visualization Widgets

Catalog widget Plot widget Table widget

Map widget Timeline widget




Catalog widget visualizes the mashup results like a catalog. It arranges mashup results on the screen using their

thumbnails, titles, and descriptions.

Catalog Widget






Plot widget plots the mashup results on a two dimensional space.

Plot Widget






Table widget presents all titles and descriptions of the mashup results in a table.

Table Widget






Map widget depicts the mashup results visually on a map.

Map Widget






Timeline widget puts the mashup results into a graphical timeline.

Timeline Widget






Ousia Weaver provides a function which automatically selects appropriate visualization widgets for the mashup.

The function scans the mashup result and detects if the result has all of the data which need to be visualized.

Also, users can choose visualization widgets manually.

Automatic Widgets Selection




Publishing Mashups

Ousia Weaver provides a lightweight server named Mashup Server.

Mashup server executes mashups dynamically and makes the mashup results accessible to external users.

The server automatically assigns a URL to each mashup and dynamically executes the mashup when an external user accesses it. ◦ The URL of a mashup named “search_videos” in the

“foo” server would be “http://foo/search_videos/”

Mashup Server




Implementation

Ousia Weaver consists of five main components:◦ Operator manager◦ Run-time engine◦ Visualizer◦ Visual Editor◦ Mashup server

Architecture

Run-timeengine

Visual editor Mashup server

Operator manager

Visualizer

Results of mashups

Metadata ofoperators

Results ofvisualization

Program codes of operators

Sources of mashups

Operator manager is a simple component implemented using Python.

It manages the list of all operators and delivers their program codes and metadata to other components.

Operator Manager

Run-timeengine


Operator manager

Visualizer

Results of mashups




Sources of mashups

Run-time engine is a component responsible for executing mashups.

It is implemented as a multi-process server daemon using Python and Python’s multiprocessing module.

Run-time Engine

Run-timeengine


Operator manager

Visualizer

Results of mashups




Sources of mashups

Visualizer is a component which visualizes mashups.

It passes the mashup result to each of the selected visualization widgets.

It is implemented in JavaScript and uses jQuery (jquery.com) and Simile Widgets (simile-widgets.org).

Visualizer

Run-timeengine


Operator manager

Visualizer

Results of mashups




Sources of mashups

Visual editor provides a rich visual editing interface for creating and publishing mashups.

It is implemented using JavaScript and HTML, and can be run on most commonly used Web browsers.

It can also be executed as a stand-alone application on Windows, Mac OS X, and Linux using Mozilla’s XUL technology.

Visual Editor

Run-timeengine

Visual editor

Mashup server

Operator manager

Visualizer

Results of mashups




Sources of mashups

Mashup server makes mashups accessible to external users.

It provides a simple Web server which returns mashup results to external users.

The mashup server is written in Python and uses Apache CouchDB as a datastore.

Mashup Server

Run-timeengine


Operator manager

Visualizer

Results of mashups




Sources of mashups

Execution Model

Mashup server executes mashups as follows:1. An external user accesses a mashup.2. It executes the mashup using the runtime engine.3. It visualizes the result using the visualizer.4. It returns the visualized result to the user.

Mashup Execution Model(Mashup Server)

(2) (1

)

(4)

Run-timeengine

Visualizer

External user

(3)

Mashup server

The basic sequence of operations of the mashup server.

Run-time engine executes mashups in parallel.◦ It divides a mashup into multiple, independent tasks and

executes them using worker processes.

The manager processes and the worker processes are recycled across mashup executions.

Mashup Execution Model(Run-time Engine)

Manager processes

Task queue

task

Workerprocesses

Add tasks

Watch progress

Take tasks

Add/getresults

Result buffer

task task

result result result

Examples

“Book Mashup” provides a simple book search function.1. Receiving a keyword from the user.2. Performing a book search on Amazon.com.3. Attaching coordinates, which consists of price

and the number of pages, to the result.4. Returning the result to the user.

Book Mashup

“Event mashup” provides an event search function.1. Receiving a keyword from the user.2. Retrieving event information from

Upcoming and Eventful.3. Adding ranges of dates of the events

to the result.4. Attaching geographic locations of the

events to the result.5. Returning the result to the user.

Event mashup

Conclusion and Future Work

We proposed a mashup editor called Ousia Weaver. ◦ Ousia Weaver provides a sophisticated visual editor which

enables users to create and publish mashups without writing any code.

◦ Ousia Weaver offers a variety of rich visualization widgets which visualize mashups in an impressive way.

◦ Ousia Weaver includes a simple Web server which makes the mashup accessible to external users.

With Ousia Weaver, users can easily create and publish mashups as impressive Web pages.

Conclusion

We plan to do an extensive user evaluation which compares Ousia Weaver to existing mashup editors.

We will continue to develop Ousia Weaver.

We are planning to release Ousia Weaver as an open source product.

Future Work

Ousia Weaver - A tool for creating and publishing mashups as impressive Web pages-

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