almost 3 years ago

摘要

1. 作者的教學網站:learnenough.com

2. Gemfile的gem版本設定

3. MVC的介紹圖

4. Git的介紹

5. 如何使用Bitbucket

6. 怎麼找Public key cat ~/.ssh/id_rsa.pub

7. 記得做任何比較大的改變的時候,都先弄一個新的branch

1. a real sample app (Chapter 3 through Chapter 12).

2. gems (self-contained solutions to specific problems such as pagination and image upload)

3. Another strategy recommended by multiple readers is simply to do the tutorial twice; you may be surprised at how much you learned the first time (and how much easier it is the second time through).

灌rails的版本

$ gem install rails -v 4.2.0

用rails指令,新建(new)一個application(hello_app)

$ rails _4.2.0_ new hello_app

4. 1.3.1 Bundler

After creating a new Rails application, the next step is to use Bundler to install and include the gems needed by the app.

5. Unless you specify a version number to the gem command, Bundler will automatically install the latest requested version of the gem. This is the case, for example, in the code gem 'sqlite3'

Gemfile注意事項
gem 'coffee-rails', '~> 4.0.0' ~> 不會超過4.1.0版本
gem 'uglifier', '>= 1.3.0' >= 高過於1.3.0的版本,譬如7.2.0
gem 'sqlite3' 沒有寫任何數字,就是會灌最新的版本

6. Unfortunately, experience shows that even minor point releases can break things, so for the Ruby on Rails Tutorial we’ll err on the side of caution by including exact version numbers for all gems.

7. Converting the Gemfile in Listing 1.4 to use exact gem versions results in the code shown inListing 1.5.

在Gemfile裡面新增任何的gem之後,都要跑一次bundle install

8. 1.3.3 Model-View-Controller (MVC)

This is a hint that Rails follows the model-view-controller (MVC) architectural pattern, which enforces a separation between “domain logic” (also called “business logic”) from the input and presentation logic associated with a graphical user interface (GUI). In the case of web applications, the “domain logic” typically consists of data models for things like users, articles, and products, and the GUI is just a web page in a web browser.

9. 1.4 Version control with Git

Version control systems allow us to track changes to our project’s code, collaborate more easily, and roll back any inadvertent errors (such as accidentally deleting files).

推薦文章:
Bitbucket Getting Started
Pro Git

10. 1.4.1 Installation and setup

Before using Git, you should perform a set of one-time setup steps. These are system setups, meaning you only have to do them once per computer:

這邊的步驟,一台電腦只要設一次:

$ git config --global user.name "Your Name"
$ git config --global user.email your.email@example.com
$ git config --global push.default matching
$ git config --global alias.co checkout

Note that the name and email address you use in your Git configuration will be available in any repositories you make public.
(Only the first two lines above are strictly necessary. The third line is included only to ensure forward-compatibility with an upcoming release of Git.The optional fourth line is included so that you can use co in place of the more verbose checkout command. For maximum compatibility with systems that don’t have co configured, this tutorial will use the full checkout command, but in real life I nearly always use git co.)

11. First-time repository setup

Now we come to some steps that are necessary each time you create a new repository(sometimes called a repo for short). First navigate to the root directory of the first app and initialize a new repository:

首先要新建一個repo

$ git init

ps 這邊跟JC大講解的不一樣:RailsFun.tw 新手教學_day2 HD
4:50 JC大:應該用 'git init --bare prodject.git'

Initialized empty Git repository in /home/ubuntu/workspace/hello_app/.git/

The next step is to add all the project files to the repository using git add -A:

把所有的檔案都夾到repo裡面去

$ git add -A

實際上,都還留在staging area,然後要commit跟給附註(-m)才能夠上傳。

This command adds all the files in the current directory apart from those that match the patterns in a special file called .gitignore. The rails new command automatically generates a .gitignore file appropriate to a Rails project, but you can add additional patterns as well.12

The added files are initially placed in a staging area, which contains pending changes to your project. You can see which files are in the staging area using the status command:

用git status來看有什麼處在pending的改變

$ git status
On branch master

Initial commit

Changes to be committed:
  (use "git rm --cached <file>..." to unstage)

  new file:   .gitignore
  new file:   Gemfile
  new file:   Gemfile.lock
  new file:   README.rdoc
  new file:   Rakefile
  .
  .
  .

To tell Git you want to keep the changes, use the commit command:
** -m 是用來寫附註的:**

$ git commit -m "Initialize repository"
[master (root-commit) df0a62f] Initialize repository
.
.
.

The -m flag lets you add a message for the commit; if you omit -m, Git will open the system’s default editor and have you enter the message there. (All the examples in this book will use the -m flag.)

其實這個時候,還留在local端,要用'git push'才會上傳
It is important to note that Git commits are local, recorded only on the machine on which the commits occur. We’ll see how to push the changes up to a remote repository (using git push) in Section 1.4.4.

By the way, you can see a list of your commit messages using the log command:

$ git log
commit df0a62f3f091e53ffa799309b3e32c27b0b38eb4
Author: Michael Hartl <michael@michaelhartl.com>
Date:   Wed August 20 19:44:43 2014 +0000

    Initialize repository
Depending on the length of your repository’s log history, you may have to type q to quit.

Let’s check the status to see what changed:

$ git status

12. 1.4.3 Bitbucket

Once you’ve added your public key, click on “Create” to create a new repository, as shown inFigure 1.14.
When filling in the information for the project, take care to leave the box next to “This is a private repository.” checked.
After clicking “Create repository”, follow the instructions under “Command line > I have an existing project”, which should look something like Listing 1.12. (If it doesn’t look like Listing 1.12, it might be because the public key didn’t get added correctly, in which case I suggest trying that step again.)
When pushing up the repository, answer yes if you see the question “Are you sure you want to continue connecting (yes/no)?”

how to install a public key on your Bitbucket account.

Public Key

Listing 1.11: Printing the public key using cat.
$ cat ~/.ssh/id_rsa.pub
Listing 1.12: Adding Bitbucket and pushing up the repository.
$ git remote add origin git@bitbucket.org:<username>/hello_app.git
$ git push -u origin --all # pushes up the repo and its refs for the first time

The commands in Listing 1.12 first tell Git that you want to add Bitbucket as the origin for your repository, and then push your repository up to the remote origin. (Don’t worry about what the -u flag does; if you’re curious, do a web search for “git set upstream”.) Of course, you should replace with your actual username. For example, the command I ran was

$ git remote add origin git@bitbucket.org:mhartl/hello_app.git

13. Branch

Git is incredibly good at making branches, which are effectively copies of a repository where we can make (possibly experimental) changes without modifying the parent files. In most cases, the parent repository is the master branch, and we can create a new topic branch by using checkout with the -b flag:

checkout -b可以新增一個new branch,同時switch去這個new branch

$ git checkout -b modify-README

Switched to a new branch 'modify-README'
$ git branch
  master
* modify-README

Here the second command, git branch, just lists all the local branches, and the asterisk *identifies which branch we’re currently on. Note that git checkout -b modify-README both creates a new branch and switches to it, as indicated by the asterisk in front of th emodify-README branch. (If you set up the co alias in Section 1.4, you can use git co -b modify-README instead.)

git commit provides the -a flag as a shortcut for the (very common) case of committing all modifications to existing files (or files created using git mv, which don’t count as new files to Git):

$ git commit -a -m "Improve the README fil

Be careful about using the -a flag improperly; if you have added any new files to the project since the last commit, you still have to tell Git about them using git add -A first.

如果只是一些小改變,可以直接用git commit -a -m,可是如果有新增檔案,就必須先用git add -A然後再用git commit -m

14 Merge

Now that we’ve finished making our changes, we’re ready to merge the results back into our master branch:

$ git checkout master
Switched to branch 'master'
$ git merge modify-README
Updating 34f06b7..2c92bef
Fast forward
README.rdoc     |  243 --------------------------------------------------
README.md       |    5 +
2 files changed, 5 insertions(+), 243 deletions(-)
delete mode 100644 README.rdoc
create mode 100644 README.md
After you’ve merged in the changes, you can tidy up your branches by deleting the topic branch using git branch -d if you’re done with it:
$ git branch -d modify-README
Deleted branch modify-README (was 2c92bef).

這邊跟JC講的不一樣:RailsFun.tw 新手教學_day2 HD

28:50

merge要先由branch去合併master
然後再由master去合併branch

通常很少把分支刪掉
This step is optional, and in fact it’s quite common to leave the topic branch intact. This way you can switch back and forth between the topic and master branches, merging in changes every time you reach a natural stopping point.

As mentioned above, it’s also possible to abandon your topic branch changes, in this case with git branch -D:
# For illustration only; don't do this unless you mess up a branch
$ git checkout -b topic-branch
$ <really screw up the branch>
$ git add -A
$ git commit -a -m "Major screw up"
$ git checkout master
$ git branch -D topic-branch

Unlike the -d flag, the -D flag will delete the branch even though we haven’t merged in the changes.
-D是可以不用merge 就可以暴力把branch刪掉

15 Push

Now that we’ve updated the README, we can push the changes up to Bitbucket to see the result. Since we have already done one push (Section 1.4.3), on most systems we can omit origin master, and simply run git push:

$ git push

1.5 Deploying - Heroku

Heroku 使用 PostgreSQL database

Heroku uses the PostgreSQL database (pronounced “post-gres-cue-ell”, and often called “Postgres” for short), which means that we need to add the pg gem in the production environment to allow Rails to talk to Postgres:17

:production 要用pg (PostgreSQL)

group :production do
  gem 'pg',             '0.17.1'
  gem 'rails_12factor', '0.0.2'
end

Note also the addition of the rails_12factor gem, which is used by Heroku to serve static assets such as images and stylesheets. Finally, be sure to incorporate the changes made in Listing 1.5 preventing the sqlite3 gem from being included in a production environment, since SQLite isn’t supported at Heroku:

:development要用sqlite3

group :development, :test do
  gem 'sqlite3',     '1.3.9'
  gem 'byebug',      '3.4.0'
  gem 'web-console', '2.0.0.beta3'
  gem 'spring',      '1.1.3'
end

雖然加上without production,不會在local端install pg跟rails_12factor這兩個gem,不過其實是更新到Gemfile.lock

$ bundle install --without production

Because the only gems added in Listing 1.14 are restricted to a production environment, right now this command doesn’t actually install any additional local gems, but it’s needed to update Gemfile.lock with the pg and rails_12factor gems.

再把剛剛做的事情在commit一下

$ git commit -a -m "Update Gemfile.lock for Heroku"

1.5.1 Heroku setup

確定有沒有灌過heroku CLI跟Heroku Toolbelt

$ heroku version

登入跟輸入SSH key
Once you’ve verified that the Heroku command-line interface is installed, use the heroku command to log in and add your SSH key:

$ heroku login
$ heroku keys:add

Finally, use the heroku create command to create a place on the Heroku servers for the sample app to live (Listing 1.15).

新建一個網址

$ heroku create

在push到heroku master,就好了

$ git push heroku master
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