Slide 2
Slide 2 text
Promise: いずれされる処理を表すオブジェクト
https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Global_Objects/Promise
1SPNJTF
UIFO GVM'JMMFE
UIFO SFKFDUFE
DBUDI SFKFDUFE
1SPNJTF
Pending
Fulfill
Reject
Return
Return
Slide 3
Slide 3 text
Promise chain
GFUDI IUUQTFYBNQMFDPNFOEQPJOUTPNFBDUJPO
UIFO SFTQPOTF SFTQPOTFKTPO
FSS OPUJGZ&SSPS FSS
UIFO EBUB EBUBMFOHUI EBUB1SPNJTFSFKFDU OPEBUB
UIFO EBUB SFOEFS%BUB EBUB
FSS OPUJGZ/P%BUB
Slide 4
Slide 4 text
処理を始めるところと、結果を利用するところを分けられる
EP4PNFUIJOH QBSBN
SFTQPOTF \
JG SFTQPOTFFSS
\
SFUVSOIBOEMF&SSPS SFTQPOTFFSS
^
EP"
EP#
EP$
EP%
DPOTVNF SFTQPOTFSFTVMU
^
DPOTUQ EP4PNFUJOH QBSBN
EP"
EP#
EP$
EP%
QUIFO DPOTVNF
DBUDI IBOEMF&SSPS
Slide 5
Slide 5 text
Promise: 条件分岐の一種
https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Global_Objects/Promise
1SPNJTF
UIFO GVM'JMMFE
UIFO SFKFDUFE
DBUDI SFKFDUFE
1SPNJTF
Pending
Fulfill
Reject
Return
Return
Slide 6
Slide 6 text
直列化
UFTU"
UIFO UFTU#
UIFO TVDDFTT
DBUDI GBJM
SFEVDF QSP
GVOD
QSPUIFO GVOD
UIFO TVDDFTT
DBUDI GBJM
1SPNJTFBMM
UIFO TVDDFTT
DBUDI GBJM
㛈ᏁҶ⼊ҿӶӔҮ
UFTU"
UFTU#
TVDDFTT GBJM
F
T
T
F
Slide 7
Slide 7 text
並列化
UFTU"
DBUDI UFTU#
UIFO TVDDFTT
DBUDI GBJM
1SPNJTFSBDF
UIFO TVDDFTT
DBUDI GBJM
㛈ᏁҶ⼊ҿӶӔҮ
UFTU"
UFTU#
TVDDFTT GBJM
F
T
T
F
Slide 8
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エラー処理を本筋と分けて実装できる
MFUSFTVMU EP4PNFUIJOH
JG SFTVMU OVMM
\
SFTVMU EFGBVMU7BMVF
^
DPOTVNF SFTVMU
EP4PNFUIJOH
DBUDI FSS EFGBVMU7BMVF
UIFO DPOTVNF
Slide 9
Slide 9 text
Promise非対応のPromise対応にするには
GVODUJPOBEE B
C
\
SFUVSOB C
^
GVODUJPOQSPNJTFE"EE B
C
\
SFUVSO1SPNJTFSFTPMWF B C
^
QSPNJTFE"EE
UIFO J DPOTPMFMPH
Slide 10
Slide 10 text
Promise非対応のPromise対応にするには
GVODUJPOBEE B
C
\
JG B ]]C
\
UISPXOFX&SSPS *OWBMJEQBSBNFUFS
^
SFUVSOB C
^
GVODUJPOQSPNJTFE"EE B
C
\
USZ\SFUVSO1SPNJTFSFTPMWF BEE B
C
^
DBUDIFSS\SFUVSO1SPNJTFSFKFDU FSS
^
^
Slide 11
Slide 11 text
Promise非対応のPromise対応にするには
DPOTUGT SFRVJSF GT
GVODUJPOSFBE GJMF
\
SFUVSOOFX1SPNJTF SFTPMWF
SFKFDU
\
GTSFBE'JMF GJMF
FSS
EBUB
\
FSS SFTPMWF FSS
SFKFDU EBUB
^
^
^
Slide 12
Slide 12 text
Promise非対応のPromise対応にするには
GVODUJPOBEE0OF OVNCFST
\
DPOTUSFTVMU <>
GPS DPOTUOVNPGOVNCFST
\
SFTVMUQVTI OVN
^
^
GVODUJPOQSPNJTFE"EE0OF OVNCFST
\
SFUVSO1SPNJTFBMM OVNCFSTNBQ J 1SPNJTFSFTPMWF J
^
Slide 13
Slide 13 text
Anti-pattern: ネストしたPromise
EP"
UIFO SFTVMU" \
EP#
UIFO SFTVMU# DPOTVNF SFTVMU"
SFTTVMU#
^
1SPNJTFBMM
UIFO SFTVMUT DPOTVNF SFTVMUT<>
SFTVMU<>
http://taoofcode.net/promise-anti-patterns/
Slide 14
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Anti-pattern: 続かないチェーン
GVODUJPOEP4PNFUIJOH
\
DPOTUQSPNJTF EP"
QSPNJTFUIFO SFTVMU DPOTVNF SFTVMU
SFUVSOQSPNJTF
^
GVODUJPOEP4PNFUIJOH
\
SFUVSOEP"
UIFO SFTVMU DPOTVNF SFTVMU
^
http://taoofcode.net/promise-anti-patterns/