looping through a collection of divs in Watir - xpath

Question

We're using watir for testing and wondered how to select a group of divs that meet a particular criteria? In our case the (simplified) html looks like this:
<div class="month_main>
<div class="month_cell">
some divs
</div>
<div class="month_cell">
some_other_divs
</div>
<div class = "month_cell OverridenDay">
<div id = "month-2013-05-04"/>
</div>
</div>
We would like to loop through all divs with an id starting with 'month' that are contained in month_cell parent divs that also have classes of OverridenDay. Is there an Xpath or regular expression we can use in conjunction with the Watir browser class to do this?

Answer 1

General
You can get a collection of elements in a similar way to getting a single element. You basically need to pluralize the element type method. For example:
#Singular method returns first matching div
browser.div
#Pluralized method returns all matching divs
browser.divs
Collections can be used using the same locators as single elements.
Solution
For your problem, you can do:
#Iterate over divs that have the class 'month_cell OverridenDay'
browser.divs(:class => 'month_cell OverridenDay').each do |overridden_div|
#Within each div with class 'month_cell OverridenDay',
# iterate over any children divs where the id starts with month
overridden_div.divs(:id => /^month/).each do |div|
#Do something with the div that has id starting with month
puts div.id
end
end
#=> "month-2013-05-0"
If you need to create a single collection that includes all of the matching divs, you will need to use a css or xpath selector.
Using a css-selector (note that in watir-webdriver, only the elements method supports css-locators):
divs = browser.elements(:css => 'div.month_cell.OverridenDay div[id^=month]')
divs.each do |e|
puts e.id
end
#=> "month-2013-05-0"
Using xpath:
divs = browser.divs(:xpath => '//div[#class="month_cell OverridenDay"]//div[starts-with(#id, "month")]')
divs.each do |e|
puts e.id
end
#=> "month-2013-05-0"