2016/08/02

Jekyll始めました

やっぱり手軽に Markdown で書きたいよね。と思っていて、どこにするかと悩んでいたんだけど、技術blogなんだからローカルに原稿残っていたほうがgrepできていいよね。ネット繋がってなくても自分の過去ログ漁れるのはかなりの利点じゃないかな?と思ったのでJekyll+Github Pagesで頑張ることにしました。→ tail -f pinzo.log

2016/07/28

serialのシーケンスがなが~い名前になる場合

<>PostgreSQLの serial はシーケンスを生成するわけだけども、シーケンスの名前は table_name_column_name_seq という形で生成される。users テーブルの id ならば users_id_seqという感じで


6363  long_long_name_table_abcd_efgh_ijkl_mnop_qrst_uvwx_yz  long_long_name_column_abcd_efgh_ijkl_mnop_qrst_uvwx_yz  sample.long_long_name_table_abcd_efg_long_long_name_column_abcd_ef_seq 

 pg_catalog.pg_get_serial_sequence 使DB



(一)58

(二)3029

(三)29使58-

js

idserial integer 

2016/06/03

golangのテンプレート内でメソッドを呼び出す


text/template 
panic: template: test:1: unexpected "(" in operand

goroutine 1 [running]:
panic(0x13f660, 0xc82000a440)
 /usr/local/Cellar/go/1.6.2/libexec/src/runtime/panic.go:481 +0x3e6
main.main()
 /Users/pinzolo/.cache/junkfile/2016/06/2016-06-03-101728.go:20 +0x24b
exit status 2


 unexpected 
pinzolo(36) lives in Kyoto.


len使
pinzolo(36) lives in Kyoto. 2 years later he is 38.


2
pinzolo(36) lives in Kyoto. 5 years later he is 41.


pinzolo(36) lives in Kyoto. 2 years later he is 38.


 text/template

2016/06/01

comment on exported function GetXxx should be of thee form "GetXxx ..."

Go は大文字で始まる public な型・関数に対してその直前に書かれたコメントをドキュメントとして扱ってくれる。
lintでドキュメント書くように勧めてくるのは意識高い感じでよい。
ただ、面倒なことにその型なり関数なりの名前で始まるのを推奨しているらしく、そうじゃない場合タイトルのような警告を出してくる。

こんな感じ

英語で書く場合なら、GetFoo returns Foo みたいに書きやすいのだが、日本語でコメントを書く場合冗長なコメントになりがちな気がする。
関数名も型名も真下にあるじゃないか!
なんて言っても仕方ないし、エディタにマークつけ続けられるのも気持ち悪いのでせっせとおっしゃる通りにするのだ

2016/05/31

golang 入門した


 gem  Windows 使 Ruby golang 

 A Tour of Go.  github.com/pinzolo/casee 


golang にて文字列のn番目の文字を取得する

文字列 s に対して、s[0] は最初のバイトを返すので、一旦 rune スライスを作成しないと n 番目の文字は取得できない。

2016/04/07

Ubuntu 12.04 on さくらのVPS に GitBucket を入れたメモ


Tomcat

sudo aptitude install -y tomcat7 tomcat7-admin


Tomcat

sudo vi /etc/tomcat7/server.xml
HTTPConnectorAJPCo
nnector

GitBucket

wget https://github.com/gitbucket/gitbucket/releases/download/3.13/gitbucket.war
sudo mv gitbucket.war /var/lib/tomcat7/webapps
ls -al /var/lib/tomcat7/webapps
drwxrwxr-x 4 tomcat7 tomcat7 4096 Apr 7 14:37 . drwxr-xr-x 6 root root 4096 Apr 7 14:24 .. drwxr-xr-x 7 tomcat7 tomcat7 4096 Apr 7 14:37 gitbucket -rw-r--r-- 1 root root 39783199 Apr 7 14:37 gitbucket.war drwxr-xr-x 3 root root 4096 Apr 7 14:25 ROOT


ApacheGitBucket

sudo vi /etc/apache2/sites-available/gitbucket.conf
<VirtualHost *:443> ServerName gitbucket.my-domain:443 <Location /> ProxyPass ajp://localhost:8009/ </Location> SSLCertificateFile /etc/apache2/cert/ssl-cert.pem SSLCertificateKeyFile /etc/apache2/cert/ssl-cert.key </VirtualHost>
sudo a2ensite gitbucket


sudo service tomcat7 restart
sudo service apache2 restart
 404 
/var/log/tomcat7/localhost.2016-04-07.log 
SEVERE: Error configuring application listener of class gitbucket.core.ssh.SshServerListener
java.lang.UnsupportedClassVersionError: gitbucket/core/ssh/SshServerListener : Unsupported major.minor version 52.0 (unable to load class gitbucket.core.ssh.SshServerListener)
        at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2948)
        at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1208)
        at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1688)
        at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1569)
        at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:529)
        at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:511)
        at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:139)
        at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4888)
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5467)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:632)
        at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1073)
        at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1857)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)
https
://github.com/gitbucket/gitbucket/issues/1082 Java8Java8TomcatJava8

JAVA_HOME

sudo vi /etc/default/tomcat7
JAVA_HOME=/usr/lib/jvm/java-8-or
acle

SEVERE: Exception sending context initialized event to listener instance of class gitbucket.core.servlet.InitializeListener
java.sql.SQLException: Connections could not be acquired from the underlying database!
        at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:118)
        at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:692)
        at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:140)
        at scala.slick.jdbc.JdbcBackend$DatabaseFactoryDef$$anon$3.createConnection(JdbcBackend.scala:47)
        at scala.slick.jdbc.JdbcBackend$BaseSession.conn$lzycompute(JdbcBackend.scala:397)
        at scala.slick.jdbc.JdbcBackend$BaseSession.conn(JdbcBackend.scala:397)
        at scala.slick.jdbc.JdbcBackend$BaseSession.withTransaction(JdbcBackend.scala:420)
        at scala.slick.backend.DatabaseComponent$DatabaseDef$$anonfun$withTransaction$1.apply(DatabaseComponent.scala:54)
        at scala.slick.backend.DatabaseComponent$DatabaseDef$$anonfun$withTransaction$1.apply(DatabaseComponent.scala:54)
        at scala.slick.backend.DatabaseComponent$DatabaseDef$class.withSession(DatabaseComponent.scala:34)
        at scala.slick.jdbc.JdbcBackend$DatabaseFactoryDef$$anon$3.withSession(JdbcBackend.scala:46)
        at scala.slick.backend.DatabaseComponent$DatabaseDef$class.withTransaction(DatabaseComponent.scala:54)
        at scala.slick.jdbc.JdbcBackend$DatabaseFactoryDef$$anon$3.withTransaction(JdbcBackend.scala:46)
        at gitbucket.core.servlet.InitializeListener.contextInitialized(InitializeListener.scala:30)
        at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4973)
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5467)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:632)
        at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1073)
        at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1857)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)
Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.
        at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1469)
        at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:644)
        at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:554)
        at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutAndMarkConnectionInUse(C3P0PooledConnectionPool.java:758)
        at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:685)
        ... 25 more
Caused by: org.h2.jdbc.JdbcSQLException: Error while creating file "/usr/share/tomcat7/.gitbucket" [90062-190]
        at org.h2.message.DbException.getJdbcSQLException(DbException.java:345)
        at org.h2.message.DbException.get(DbException.java:179)
        at org.h2.message.DbException.get(DbException.java:155)
        at org.h2.store.fs.FilePathDisk.createDirectory(FilePathDisk.java:274)
        at org.h2.store.fs.FileUtils.createDirectory(FileUtils.java:42)
        at org.h2.store.fs.FileUtils.createDirectories(FileUtils.java:309)
        at org.h2.mvstore.db.MVTableEngine.init(MVTableEngine.java:73)
        at org.h2.engine.Database.getPageStore(Database.java:2450)
        at org.h2.engine.Database.open(Database.java:672)
        at org.h2.engine.Database.openDatabase(Database.java:269)
        at org.h2.engine.Database.(Database.java:263)
        at org.h2.engine.Engine.openSession(Engine.java:65)
        at org.h2.engine.Engine.openSession(Engine.java:175)
        at org.h2.engine.Engine.createSessionAndValidate(Engine.java:153)
        at org.h2.engine.Engine.createSession(Engine.java:136)
        at org.h2.engine.Engine.createSession(Engine.java:28)
        at org.h2.engine.SessionRemote.connectEmbeddedOrServer(SessionRemote.java:349)
        at org.h2.jdbc.JdbcConnection.(JdbcConnection.java:107)
        at org.h2.jdbc.JdbcConnection.(JdbcConnection.java:91)
        at org.h2.Driver.connect(Driver.java:72)
        at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:175)
        at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:220)
        at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:206)
        at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:203)
        at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1138)
        at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1125)
        at com.mchange.v2.resourcepool.BasicResourcePool.access$700(BasicResourcePool.java:44)
        at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1870)
        at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)
/usr/share/tomcat7/.gitbucket 

ls -al /usr/share/tomcat7
drwxr-xr-x 4 root root 4096 Apr 7 14:24 . drwxr-xr-x 155 root root 4096 Apr 7 14:25 .. drwxr-xr-x 2 root root 4096 Apr 7 14:24 bin -rw-r--r-- 1 root root 39 Feb 21 2014 defaults.md5sum -rw-r--r-- 1 root root 2030 Feb 21 2014 defaults.template drwxr-xr-x 2 root root 4096 Apr 7 14:24 lib -rw-r--r-- 1 root root 53 Feb 21 2014 logrotate.md5sum -rw-r--r-- 1 root root 118 Feb 21 2014 logrotate.template
root

/usr/share/tomcat7/.gitbucke

sudo chown -R tomcat7:tomcat7 /usr/share/tomcat7
 assets 

assets

 assets  VirtualHost /gitbucket  /gitbucket/assets 
 /etc/apache2/sites-available/gitbucket.conf 
<VirtualHost *:443>
  ServerName gitbucket.my-domain:443
  ProxyReverseHost On
  RewriteEngine On
  ProxyPass /gitbucket ajp://localhost:8009/gitbucket/
  ProxyPassReverse /gitbucket ajp://localhost:8009/gitbucket/
  ProxyPass /gitbucket/assets ! # 静的ファイルはAapacheに処理させる
  Redirect / /gitbucket # ルートにアクセスしても大丈夫なように
  RewriteRule ^/gitbucket/(.*) ajp://localhost:8009/gitbucket/$1 [P,L,QSA]
  SSLCertificateFile    /etc/apache2/cert/ssl-cert.pem
  SSLCertificateKeyFile /etc/apache2/cert/ssl-cert.key
</VirtualHost>
Rewri
teRule 

Ubuntu 12.04 on さくらのVPS に Jenkins を入れたメモ

Jenkinsのインストール

wget -q -O - http://pkg.jenkins-ci.org/debian/jenkins-ci.org.key | sudo apt-key add -
sudo sh -c 'echo "deb http://pkg.jenkins-ci.org/debian binary/" > /etc/apt/sources.list.d/jenkins.list'
sudo aptitude update
sudo aptitude install -y jenkins

Jenkinsの設定変更

sudo vi /etc/default/jenkins
HTTP_PORTを-1に、AJP_PORTを8008に(Tomcat導入予定のため)

Apacheの設定

sudo vi /etc/apache2/sites-available/jenkins.conf
<VirtualHost *:443> ServerName jenkins.my-domain:443 <Location /> ProxyPass ajp://localhost:8008/ </Location> SSLCertificateFile /etc/apache2/cert/ssl-cert.pem SSLCertificateKeyFile /etc/apache2/cert/ssl-cert.key </VirtualHost>
sudo a2ensite jenkins

再起動

sudo service jenkins restart
sudo service apache2 restart

とっても簡単だった

2016/04/06

git 2.0.0 → git 2.8.1

% git --version
git version 2.0.0
% cd /opt/src % wget https://www.kernel.org/pub/software/scm/git/git-2.8.1.tar.gz % tar xf git-2.8.1.tar.gz % cd git-2.8.1 % ./configure --prefix=/opt/git/git-2.8.1 --with-openssl --with-curl % make % make install % /opt/git/git-2.8.1/bin/git --version
git version 2.8.1
% ln -sfn /opt/git/git-2.8.1/bin/* /usr/bin % git --version
git version 2.8.1
とくに問題なし、前回と同じ。

2016/03/12

よくあるテーブルのヘッダ固定の1つ




2bodydiv overflow-y IE

header

header

AngularJS  directive  jQuery 

Bootstrappanelbody

 thead 1


2016/03/08

お使いの起動ディスクは一杯です

作業中に「お使いの起動ディスクは一杯です」というダイアログが表示された。

この3つのコマンド走らせるだけで、30Gほど空きスペースを確保できた。

ちょっと放置し過ぎか

2016/02/25

JavaでPostgreSQLの?演算子を使用するために


PostgreSQL  ?JSONB
-- true を返す
SELECT '["a", "b", "c"]' ? 'a';

-- 管理者検索
SELECT *
FROM users
WHERE roles ? 'ADMIN';
使

 DOMA JDBC使


 ?
-- true を返す
SELECT '["a", "b", "c"]' ?? 'a';

-- 管理者検索
SELECT *
FROM users
WHERE roles ?? 'ADMIN';

2016/02/03

FactoryGirlを使用したDeviseのテストでLinuxとMacでのテスト結果が異なった話


tail -f pinzo.log: Devise MacAmazon Linux





Mac
[test-code][sent_at] to_s: 2016-02-01 23:51:31 +0900, to_i: 1454338291, usec: 197593, subsec: 197593/1000000
[test-code][added]   to_s: 2016-02-11 23:51:31 +0900, to_i: 1456930291, usec: 197593, subsec: 197593/1000000
[devise][now]     to_s: 2016-02-11 23:51:31 +0900, to_i: 1456930291, usec: 197593, subsec: 197593/1000000
[devise][sent_at] to_s: 2016-02-01 23:51:31 +0900, to_i: 1454338291, usec: 197593, subsec: 197593/1000000
[devise][added]   to_s: 2016-02-11 23:51:31 +0900, to_i: 1456930291, usec: 197593, subsec: 197593/1000000
[devise] now > added: false
[devise] now.subsec > added.subsec: false

Amazon Linux
[test-code][sent_at] to_s: 2016-02-01 23:53:20 +0900, to_i: 1454338400, usec: 369658, subsec: 369658841/1000000000
[test-code][added]   to_s: 2016-02-11 23:53:20 +0900, to_i: 1456930400, usec: 369658, subsec: 369658841/1000000000
[devise][now]     to_s: 2016-02-11 23:53:20 +0900, to_i: 1456930400, usec: 369658, subsec: 369658841/1000000000
[devise][sent_at] to_s: 2016-02-01 23:53:20 +0900, to_i: 1454338400, usec: 369658, subsec: 184829/500000
[devise][added]   to_s: 2016-02-11 23:53:20 +0900, to_i: 1456930400, usec: 369658, subsec: 184829/500000
[devise] now > added: true
[devise] now.subsec > added.subsec: true

usecsubsec  Amazon Linux 

 Time.now.subsec 
# mac
$ ruby -e 'puts Time.now.subsec'
276987/1000000

# Amazon Linux
$ ruby -e 'puts Time.now.subsec'
704462593/1000000000



(一)OS Time#subsec 

(二)FactoryGirl create DB confirmation_sent_at 

(三)DBsqliteDB

(四)DB

(五)DBDB

(六)MacTime#subsecsqlite



DB

 Mac  usec 


2016/01/30

Deviseで複数モデルを利用した場合、ログアウトすると全てのスコープでログアウトされてしまう


Devise 使scoped_viewstrueRuby - Railsdevise - Qiita

 Devise 

config/initializers/devise.rb  config.sign_out_all_scopes = false 

false

テストコード込みのサンプルコードはこんな感じ。

2016/01/18

Rails の TimeWithZone を JavaScript で読み込めるフォーマットで出力する


JavaScript  new Date(text)  Date.parse(text)  TimeWithZone 

 to_s  2015-01-18 12:34:56 +0900  Chrome 

2015/01/18 12:34:56 +0900  Chrome, IE, Firefox 

 to_json 

to_json 

使

2016/01/10

EC2(Amazon Linux)上のRailsアプリにQiita::Markdownをインストール

インストール


Qiita::Markdown Pygments 使(sudo pip install pygments)

 Gemfile  gem 'qiita-markdown'  bundle install 
Installing charlock_holmes 0.7.3 with native extensions

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    /usr/bin/ruby2.2 -r ./siteconf20160110-30152-1igbivj.rb extconf.rb
checking for main() in -licui18n... no
which: no brew in (/home/ec2-user/bin:/home/ec2-user/.rbenv/bin:/home/ec2-user/bin:/home/ec2-user/.rbenv/bin:/usr/local/bin:/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/sbin:/opt/aws/bin:/home/ec2-user/.local/bin:/home/ec2-user/bin:/opt/aws/bin:/opt/aws/bin:/home/ec2-user/.local/bin:/home/ec2-user/bin:/opt/aws/bin)
checking for main() in -licui18n... no


***************************************************************************************
*********** icu required (brew install icu4c or apt-get install libicu-dev) ***********
***************************************************************************************
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib64
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=/usr/bin/$(RUBY_BASE_NAME)2.2
        --with-icu-dir
        --without-icu-dir
        --with-icu-include
        --without-icu-include=${icu-dir}/include
        --with-icu-lib
        --without-icu-lib=${icu-dir}/lib64
        --with-icui18nlib
        --without-icui18nlib
        --with-icui18nlib
        --without-icui18nlib

extconf failed, exit code 1

Gem files will remain installed in /home/ec2-user/rails_app/vendor/bundle/ruby/2.2/gems/charlock_holmes-0.7.3 for inspection.
Results logged to /home/ec2-user/rails_app/vendor/bundle/ruby/2.2/extensions/x86_64-linux/2.2/charlock_holmes-0.7.3/gem_make.out
Installing rugged 0.24.0b11 with native extensions

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    /usr/bin/ruby2.2 -r ./siteconf20160110-30152-1y0cp2j.rb extconf.rb
checking for gmake... yes
checking for cmake... no
ERROR: CMake is required to build Rugged.
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib64
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=/usr/bin/$(RUBY_BASE_NAME)2.2
        --use-system-libraries

extconf failed, exit code 1

Gem files will remain installed in /home/ec2-user/rails_app/vendor/bundle/ruby/2.2/gems/rugged-0.24.0b11 for inspection.
Results logged to /home/ec2-user/rails_app/vendor/bundle/ruby/2.2/extensions/x86_64-linux/2.2/rugged-0.24.0b11/gem_make.out

2Amazon Linux yum libicu-dev  libicu-devel OK

sudo yum install -y libicu-devel cmake  bundle install 


使 Markdown 
module ApplicationHelper
  def markdown(source)
    Qiita::Markdown::Processor.new.call(source)[:output].to_s.html_safe
  end
end



richleland/pygments-css 



gemoji | RubyGems.org | your community gem host Rakefile 
load 'tasks/emoji.rake'
 bundle 
exec rake emoji  /public/images/emoji 
bundle  rake  /public/images/emoji  .gitignore  

2016/01/09

オブジェクトが存在するときにだけ処理をする


 Object#tap

foo.bar.baz.tap do |baz|
  do_something(baz) if baz
end


tap_if 便
foo.bar.baz.tap_if do |baz|
  do_something(baz)
end

# もしくは
foo.bar.tap_if(:baz) do |baz|
  do_something(baz)
end


 tap-if | RubyGems.org | your community gem host

 Rails  try 
foo.bar.baz.try do |baz|
  do_something(baz)
end

# もしくは
foo.bar.try(:baz) do |baz|
  do_something(baz)
end

結論:Object#try サイコー