Embed Size (px)
Citation preview
Recovering the Behaviour of AJAX
Applications
Ahmed E.
Hassan
BramAdams
ShaneMcIntosh
YingZou
Traditional Web App Model
User waits while theresponse is generated!
2
AJAX Web App Model
User may interact with the page while response is
prepared
XMLHttpRequest
3
Web app engineering is hard
4
Extraordinarytime pressure
[MacDonald:WWW:2001][Pressman:IEEE
Softw:17(1):2000]
Web app engineering is hard
5
Extraordinarytime pressure
SE Process isjust overhead!
Lack of SEProcess
Web Dev
[MacDonald:WWW:2001][Pressman:IEEE
Softw:17(1):2000]
Web app engineering is hard
6
Extraordinarytime pressure
SE Process isjust overhead!
Lack of SEProcess
Web Dev
Short EmployeeTurnover Rate
I think it’s time fora change of scenery
[MacDonald:WWW:2001][Pressman:IEEE
Softw:17(1):2000]
Consider the New Developer
Out-of-datedocumentatio
n /** * @author Bob * This routine always * returns true */ bool hasDoodad() {
return false; }
7
Consider the New Developer
Out-of-datedocumentatio
n /** * @author Bob * This routine always * returns true */ bool hasDoodad() {
return false; }
Lack of seniorpersonnel
“Bob no longer works here.”
8
MailSimilar
AJAX is everywhere!Instant
It is critical that these applications are carefully designed and maintained!
10
1. Code sharing
Recovering the Behaviour of AJAX
Apps
Feature 1 Feature 2
11
2. Robustness1. Code sharing
Feature 1 Feature 2
12
Recovering the Behaviour of AJAX
Apps
Exploratory case study
LOC
Domain AJAX fordecoration
Timemanagement
Socialnews
6,744 9,380 11,368
13
Is behaviour shared amongst AJAX app
features?
+DTrace
Navigate feature 1.
foo()bar()
14
Is behaviour shared amongst AJAX app
features?
+DTrace
Navigate feature 2.
foo()bar()
foo()baz()
Feature 1
15
Is behaviour shared amongst AJAX app
features?foo()bar()
foo()baz()
Feature 1 Feature 2
foo()
SharedBehaviour
bar()
Feature 1specific
Feature 2specific
baz()
16
Traces are Indexed by Connection State
foo()bar()
Feature 1
17
Traces are Indexed by Connection State
foo()bar()
Feature 1
18
UNSENT
Traces are Indexed by Connection State
foo()bar()
Feature 1
19
UNSENTOPENED
Traces are Indexed by Connection State
foo()bar()
Feature 1
20
UNSENTOPENED
HEADER_RECEIVED
Traces are Indexed by Connection State
foo()bar()
Feature 1
21
UNSENTOPENED
HEADER_RECEIVED
LOADING
Traces are Indexed by Connection State
foo()bar()
Feature 1
22
UNSENTOPENED
HEADER_RECEIVED
LOADINGDONE
Traces are Indexed by Connection State
foo()bar()
Feature 1
23
UNSENTOPENED
HEADER_RECEIVED
LOADINGDONE
Sequence Diagrams Show Shared and Feature Behaviour
Feature-specific
24
Sequence Diagrams Show Shared and Feature Behaviour
Feature-specific
25
Sequence Diagrams Show Shared and Feature Behaviour
Feature-specific
26
Feature-specific
27
Most behaviour is shared amongst
featuresXmlHttpRequest
State
80% 50%UNSENTOPENED
HEADER_RECEIVED
LOADINGDONE
100%100%100%100%
58%100%100%62%
29
Most behaviour is shared amongst
featuresXmlHttpRequest
State
80% 50%UNSENTOPENED
HEADER_RECEIVED
LOADINGDONE
100%100%100%100%
58%100%100%62%
30
Design Features are Revealed
31
Design Features are Revealed
32
Request BatchingMechanism
Design Features are Revealed
33
Design Features are Revealed
34
Flood preventiontechnique
•Most states share a lot of behaviour
•Guided inspection shows designs for reuse
35
Is behaviour shared amongst AJAX app
features?
Yes
+DTrace
Navigate feature.
foo()bar()
Are AJAX apps prepared for loss of
network connectivity?
36
+DTrace
Navigate feature.
foo()bar()
foo()err()
Standardworkflow
Are AJAX apps prepared for loss of
network connectivity?
37
foo()bar()
foo()err()
Errorworkflow
foo()
SharedBehaviour
bar() err()
Are AJAX apps prepared for loss of
network connectivity?Standardworkflow
Standardspecific
Errorspecific
38
Studied Apps Seem Unprepared for Lack of
Connectivity
Unsettling behaviour given the trend towardswireless and mobile networking!
Vote was notsent to the server!
39
Are AJAX apps prepared for loss of
network connectivity?
40
•UI state often out-of-sync with server
Inconclusive, but unsettling
Threats to Validity
No serverside
analysis41
Threats to Validity
No serverside
analysis
Obfuscated Javascript is not handled gracefully
42
Threats to Validity
AJAXprojects
No serverside
analysis
Obfuscated Javascript is not handled gracefully
43
Threats to Validity Studiedprojects
AJAXprojects
No serverside
analysis
Obfuscated Javascript is not handled gracefully
44
Questions?
45
