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...
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...
...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;
...to mix different database dumps. It also requires that the mixed tables do not share relations to other database objects. Scenario You've got two database dumps: dump_a.pgdump dump_b.pgdump
...that the selected table(s) might depend upon. Therefore, there is no guarantee that a specific-table restore into a clean database will succeed. Valid restore To archive a complete...
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...
...is edited by WSYIWYG-Editor but want some length checking nevertheless, you need to strip all tags and then the special characters: def hard_sanitize(text) ActionController::Base.helpers.strip_tags(text...
...gsub(/[^[:word:]]+/, " ") end :001 > hard_sanitize("This is beautiful markup ") => "This is beautiful markup" If you allready have nokogiri on board, you can use that as well, though it has...
...when you work for clients from Europe or the US, there are two dominantish standards you should know about. Each of these has subtle differences. ISO 8601 This is adhered...
...to by most European countries. Weeks start on Monday and end on Sunday. To get the number of the weekday in Ruby as defined by ISO 8601, use Date#cwday...
Delegating methods to other objects is often helpful but the syntax of both def_delegators and def_delegator is a complete mess that makes your code hard to read.
...ActiveRecord::Base belongs_to :topic def_delegators :topic, :title, :category end Here, we can say Post.new.title and actually read title from the Post's Topic object. Because of what we...
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...
The SQL code generated by Graticule's spherical distance computation is insufficient and can lead to NULL distances in edge cases. The reason for this is that MySQL is performing...
...several sine and cosine computations which can result in slight rounding errors -- which is usually okay. Rarely, though, for the exact center of the given circle, it is then asked...
Given those modules: module A def foo; end def bar; end end module B end When you want to call...
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...
...MySQL and you know the "error" is okay (e.g. you've executed the same statement at the same time on 2 masters which sync each other), you can skip this...
...error and continue with the replication without having to set up the slave from the ground up. stop slave; set global sql_slave_skip_counter = 1; start slave;
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
...written in pure Ruby and integrates with Rails applications. It provides features as automatic sizing of dots and lines (the more values, the thinner the graph's elements), custom or...
...predefined themes, different styles (bar, line, dot and many more) and multiple graphs in one chart. Installation In your Gemfile: gem 'rmagick', :require => false gem 'gruff' Then run bundle install...
...entering only http://example.com/). If you want to make a request to that site's web server without actually talking to www.example.com (e.g. because this is a load balancer...
...s address but you want to access one specific machine), you cannot just request machine1.example.com or localhost as the above vhost will redirect your request. When talking HTTP 1.1, your...
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...
How to ignore new files Globally Add the path(s) to your file(s) which you would like to ignore...
can’t find executable rails for rails-3.2.3 (Gem::Exception) ... one of several...
...things might be wrong. You're using RVM It's possible that you have a system-wide gem executable (like rails) that requires a gem that is not available in...
When a nginx reverse proxy complains about upstreams sending too big headers, tweaking the buffers responsibly can help to prevent this issue. Example log message: upstream sent too big header...
...while reading response header from upstream, client: 192.0.2.100, server: localhost, request: "GET /index.html HTTP/1.1", upstream: "http://198.51.100.123:80/index.html", host: "192.0.2.10:80" The cause This behaviour was caused by an application...
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:
On your local system that only hosts non-critical development data and only you have access to, you can store MySQL's root password in your home directory so you...
...out of the question if there's any confidential data in your databases. Assuming diligent screen-locking, an encrypted hard disk and correct permissions set on your credential file, it...
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...