Rails%203%20In%20Action

76 CHAPTER 3 Developing a real Rails application
though, you should change the line in the feature that checks for the title on the page
to the following:
And I should see "TextMate 2 - Projects - Ticketee"
When you run this feature, it should be broken:
expected #has_content?("TextMate 2 - Projects - Ticketee")
to return true, got false
Now you can fix it by replacing the line that sets @title in your show template with
this one:
You don’t need Ticketee here any more because the method puts it in for you. Let’s
replace the title tag line with this:
Ticketee
This code uses a new method called content_for?, which checks that the specified
content block is defined. If it is, you use yield and pass it the name of the content
block, which causes the content for that block to be rendered. If it isn’t, then you just
output the word Ticketee, and that becomes the title.
When you run this feature again, it passes:
...
And I should see "TextMate 2 - Projects - Ticketee"
1 scenario (1 passed)
7 steps (7 passed)
That’s a lot neater now, isn’t it? Let’s create a commit for that functionality and push
your changes:
git add .
git commit -m "Added title functionality for show page"
git push
Next up, we look at how to stop users from entering invalid data into your forms.
3.2.5 Validations
The next problem to solve is preventing users from leaving a required field blank. A
project with no name isn’t useful to anybody. Thankfully, Active Record provides validations
for this issue. Validations are run just before an object is saved to the database,
and if the validations fail, then the object isn’t saved. When this happens, you want to
tell the user what went wrong, so you write a feature that looks like the following listing.