Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Week based calendar and iOS
Search
Oleksandr Dodatko
December 22, 2012
Programming
0
110
Week based calendar and iOS
This talk covers some aspects of working with dates, calendars in iOS and SQLite
Oleksandr Dodatko
December 22, 2012
Tweet
Share
More Decks by Oleksandr Dodatko
See All by Oleksandr Dodatko
From Objective-C to Xamarin
dodikk
1
230
Building libraries for iOS — Going native (v2)
dodikk
3
280
Building libraries for iOS — Going native
dodikk
2
190
iAsync Functional Programming in Objective-C
dodikk
1
180
RubyMotion : A fly in the ointment
dodikk
0
61
iContinuousIntegration
dodikk
0
84
Other Decks in Programming
See All in Programming
JSONataを使ってみよう Step Functionsが楽しくなる実践テクニック #devio2025
dafujii
1
530
私の後悔をAWS DMSで解決した話
hiramax
4
210
CJK and Unicode From a PHP Committer
youkidearitai
PRO
0
110
Ruby×iOSアプリ開発 ~共に歩んだエコシステムの物語~
temoki
0
320
プロパティベーステストによるUIテスト: LLMによるプロパティ定義生成でエッジケースを捉える
tetta_pdnt
0
330
go test -json そして testing.T.Attr / Kyoto.go #63
utgwkk
3
300
意外と簡単!?フロントエンドでパスキー認証を実現する WebAuthn
teamlab
PRO
2
750
RDoc meets YARD
okuramasafumi
4
170
The Past, Present, and Future of Enterprise Java
ivargrimstad
0
370
今だからこそ入門する Server-Sent Events (SSE)
nearme_tech
PRO
3
210
Kiroで始めるAI-DLC
kaonash
2
590
FindyにおけるTakumi活用と脆弱性管理のこれから
rvirus0817
0
510
Featured
See All Featured
Cheating the UX When There Is Nothing More to Optimize - PixelPioneers
stephaniewalter
285
13k
The Language of Interfaces
destraynor
161
25k
VelocityConf: Rendering Performance Case Studies
addyosmani
332
24k
Building Better People: How to give real-time feedback that sticks.
wjessup
368
19k
The Web Performance Landscape in 2024 [PerfNow 2024]
tammyeverts
9
810
Improving Core Web Vitals using Speculation Rules API
sergeychernyshev
18
1.1k
Save Time (by Creating Custom Rails Generators)
garrettdimon
PRO
32
1.6k
Balancing Empowerment & Direction
lara
3
620
Rails Girls Zürich Keynote
gr2m
95
14k
Refactoring Trust on Your Teams (GOTO; Chicago 2020)
rmw
34
3.1k
Stop Working from a Prison Cell
hatefulcrawdad
271
21k
A Tale of Four Properties
chriscoyier
160
23k
Transcript
Dodatko Alexander November 2012
None
How many months does the year consist of?
What is the first day of the year?
What day does a new week start on?
Right, but did you know that ...
Jewish calendar consists of 13 months. And month #6 is
a leaping one.
In Japan the calendar may return to year #1 at
the day of the emperor's death
In Russia week starts on Monday. In the USA the
first day is Sunday
None
Dates must look in the way the user expects
None
None
-(NSDate*)parseDate:( NSString* )date_ { NSDateFormatter* df_ = [ NSDateFormatter new
]; df_.dateFormat = @"yyyy-MM-dd"; return [ df_ dateFromString: date_ ]; } The Typical Solution
-(NSDate*)parseDate:( NSString* )date_ { NSDateFormatter* df_ = [ NSDateFormatter new
]; df_.dateFormat = @"yyyy-MM-dd"; return [ df_ dateFromString: date_ ]; } WRONG !
None
Use en_US_POSIX locale for dates from the network Use Gregorian
calendar too
None
Do not forget to set the same Locale for both
NSCalendar and NSDateFormatter
Or let my library do it for you dodikk /
ESLocale
Ok. How about SQLite?
None
SELECT SUM( Visits) FROM VisitsLog WHERE Date BETWEEN x AND
y GROUP BY week
What should I take as week ?
SELECT SUM( Visits) FROM VisitsLog WHERE Date BETWEEN x AND
y GROUP BY Strftime('%Y-%W', Date )
SELECT SUM( Visits) FROM VisitsLog WHERE Date BETWEEN x AND
y GROUP BY Strftime('%Y-%W', Date )
None
SELECT SUM( Visits) FROM VisitsLog WHERE Date BETWEEN x AND
y GROUP BY ObjcFormatDate('YYYY-ww', Date, 'en_US_POSIX' )
None
int sqlite3_create_function( dbHandle, "ObjcFormatDate", 3, //int nArg, SQLITE_UTF8, NULL, //
sqlite user data functionPointer, NULL, NULL // for aggregates );
Plan of attack Convert C strings to NSString Convert date
string to NSDate Format NSDate using locale
SQLite uses ANSI format yyyy-MM-dd
Demo
One More Thing
None
1000 times slower than strftime 10K records Creating NSDateFormatter on-the-fly
None
Same speed as strftime Same 10K records Singletone NSDateFormatter
Thread Safety
dodikk / ESLocale
Contacts Oleksandr Dodatko mail/jabber :
[email protected]
Skype : alexander.dodatko.work Twitter
: @dodikk88 Github : https://github.com/dodikk https://github.com/EmbeddedSources
None