...need to use XPath, you can have Nokogiri help you out on creating it. Simply use Nokogiri's xpath_for: Nokogiri::CSS.xpath_for('#foo') # => ["//*[@id = 'foo']"] Nokogiri::CSS.xpath_for('#foo...
...bar:nth-of-type(2)') # => ["//*[@id = 'foo']//*[contains(concat(' ', @class, ' '), ' bar ') and position() = 2]"] Since XPath is more powerful you may still need to do some hardcore XPath hacking eventually...
If you have ... an object that defines to_hash (may well be a simple Hash instance) and pass it to a method with optional arguments and keyword arguments
...it is not set as the first optional argument. Instead, Ruby calls to_hash on the object and tries to match the result to keyword arguments. If the hash contains...
tl;dr: Do not use merge! for session hashes. Use update instead. Outline Let's assume you're modifying the Rails session. For simplicity, let's also assume your session...
...is empty when you start (same effect when there is data): # In our example, we're in a Rack middleware request = Rack::Request.new(env) request.session.merge! :hello => 'Universe' request.session => {} Wat?
Capistrano 3 is a major rework of the framework and requires several adjustments to your deploy configuration files. The biggest change is that they moved away from their custom DSL...
...release_roles|...) :some_role do Resources Very helpful, leads you 90% of the upgrade: https://semaphoreci.com/blog/2013/11/26/capistrano-3-upgrade-guide.html Official documentation Many examples of SSHKit...
Just found out about a great feature in Rails that seems to be around since Rails 2. Start a console with the --sandbox (or -s) parameter: rails console --sandbox
...database will be rolled back on exit. Warning Changes beyond the database (deleting files, sending emails, etc) cannot be rolled back...
...lambdas in Ruby work, check out the code at the attached link. Here the summary: ^ ---------------------------- Section 6: Summary ---------------------------- So, what's the final verdict on those 7 closure-like entities...
...method Y closure yes The things within each of these groups are all semantically identical -- that is, they're different syntaxes for the same thing: 1. block (called with yield...
...take the content-box for the element's shape, i.e. without margin, padding and border. shape-outside: content-box Set the margin where you want it, e.g. 10px left and...
Set the shape-margin to the same size as the margin. Note that the shape-margin can never exceed the (rectangular) margin-box of an element! --margin: 10px;
If you want to see how long your database queries actually take, you need to disable MySQL's query cache. This can be done globally by logging into a database...
SET GLOBAL query_cache_type=OFF; and restart your rails server. You can also disable the cache on a per query basis by saying SELECT SQL_NO_CACHE...
...Ruby parser module of Ruby-GetText comes across a file in one of its search directories (e.g. lib/scripts/) and finds out that you are defining ActiveRecord classes inside it, it...
...the whole file. Here is how to avoid that. What's happening? Let's say you have the following script which is only run once, manually, via script/runner: # lib/scripts/doomsday.rb
jQuery's deferred objects behave somewhat like standard promises, but not really. One of many subtle differences is that there are two ways to chain callbacks to an async functions...
...is done, which only exists in jQuery: $.ajax('/foo').done(function(html) { console.debug("The server responded with %s", html); }); There is also then, which all promise libraries have:
...use Solr by calling Article.search { fulltext(title) paginate(:per_page => limit) } Now look at http://sunspot.github.com/docs/ to learn about all the possibilities of Sunspot. Overwrite Sunspots' search method
...your SysOp team that you'll need Solr on staging and production, on Ubuntu the solr-common will provide what you need. First of all you should provide Solr with...
Sometimes you may want to print files from the command line, especially when you have lots of them. You can use lp for that. To print a single example.pdf file...
...on your default printer, simply say: lp example.pdf lp accepts multiple filenames, so to print all PDF files in the current directory: lp *.pdf You can specify a printer via...
In Rubocop you might notice the cop Style/CaseEquality for e.g. this example: def foo(expected, actual) expected === actual end In case expected is a Regex, it suggests to change it...
...foo(expected, actual) expected.match?(actual) end In case expected is a Regex or a String, you need to keep ===. Otherwise the actual expression is always converted to a regular expression...
The sprintf method has a reference by name format option: sprintf("% d : % f", { :foo => 1, :bar => 2 }) # => 1 : 2.000000 sprintf("%{foo}f", { :foo => 1 }) # => "1f" The format identifier % stands for...
...this example we are using %s identifier to replace strings. class Fetcher FIND_URI = 'https://someapi.com/3/search/record?query=% s&include_many=% s&language=en-US&page=1' # some public methods
Chromedriver (or selenium-webdriver?) will not reliably scroll elements into view before clicking them, and actually not click the element because of that. We've seen this happen for elements...
...a 40px button). Our assumption is that the element is considered visible (i.e. Capybara::Selenium::ChromeNode#visible? returns true for such elements) but the Selenium driver wants to actually click...
See the attached link for a useful overview of modern (and classic) DOM API methods, like matches, contains, append, cssText, etc. You will still need to look up some documentation...
...e.g. on how to modify a ClassList, but it's still better than browsing interfaces and superclasses of Element on MDN without knowing what to look for. When coming from...
gem install foobar --version="=2.3.0.alpha2" Also bundle update will never update a stable version to a pre-release version unless the user explicitly requests it in the Gemfile...
...gem 'foobar', '=2.3.0.alpha2' A note on Semantic Versioning Semantic Versioning has a naming convention for pre-releases that is incompatible with that from RubyGems. In Semantic Versioning, the version...
You can scale background images in CSS to the container size using background-size (Demo). Commonly, we use contain or cover because we want to preserve the image's aspect...
If you do not want to do that, simply provide scaling values for X and Y: background-size: 100% 100% (a simple 100% would mean 100% auto and respect...
You have an async function that rejects: async function failingFunction() { throw new Error("Something went wrong") } When you call that function in a test, your test will fail:
}) The failure message will look like this: Unhandled promise rejection: Error: Something went wrong You can fix this by expecting the state of the returned promise:
This card shows you how to format a card's content using Markdown. We use the Commonmarker interpreter, so here are examples for its dialect. Formatting **Bold** Bold _Italics_
Add a new line for a paragraph. Headlines Underline headlines with an equals sign or dash -- or start a line with a hash symbol: Hello World ----------- Lorem ipsum...
In CI test runs I noticed that string sorting order changed after switching from a debian-based PostgreSQL docker image to one that is based on Alpine Linux.
...sorting: bar Bar foo Foo Alpine image sorting: Bar Foo bar foo Explanation Alpine Linux is a very slim linux distribution that results in small docker image sizes (roughly 100MB...
...what git checkout and git reset do. Git basics A commit holds a certain state of...
...a directory and a pointer to its antecedent commit. A commit is identified by a so-called ref looking something like 7153617ff70e716e229a823cdd205ebb13fa314d. HEAD is a pointer that is always pointing...
...you can install the official Java JRE: sudo apt-get update sudo apt-get install sun-java6-jre You can now check your default JVM with java -version. It should...
...versions below 10.10. If it does, please update this note. sudo add-apt-repository ppa:sun-java-community-team/sun-java6 You probably want to get rid of OpenJDK (which is...
If you have an html_safe string, you won't be able to call gsub with a block and match reference variables like $1. They will be nil inside the...
...with rails_xss) as well as Rails 3 applications. Here is a fix to SafeBuffer#gsub. Note that it will only fix the $1 behavior, not give you a safe...