Git: Improve your commits by reviewing changes one-by-one
Git commits should be very deliberate, and only contain changes that you really want to be in there. In order to reduce the chance to accidentally commit something you didn't intend, review your changes before committing.
My preferred way of doing this is (only using git)
git add -N . # Add all paths, but not their contents
git add -p
Git will now show you all your changes in small chunks and ask you in an interactive mode whether you really want to add them.
The most helpful commands are
- y: yes (add the change)
- ...
Debugging Apache's mod_rewrite
Debugging .htaccess is hell, and RewriteRules in particular if they are not working as expected. But fear not! RewriteLog will help you out. \
Add this to your vhost's configuration:
RewriteLog "/tmp/rewrite.log"
RewriteLogLevel 9
After that, restart your Apache httpd and tail the above logfile.
When you are done and all is well: remember to remove those entries again, or set the log level to 0, to switch off rewrite logging.
Force absolute URLs for parts of a view or controller
You know that you can force absolute URLs throughout a response. Now you want to modify URLs similarly, but only in parts of a view (or controller) logic. Here is how.
Note: this has only been tested on a Rails 2 application. It should work similarly for Rails 3.
Put this into your ApplicationController:
def rewrite_options(*args)
options = super
options.merge!(:only_path => false) if @with_full_urls
options
end...
How to solve Selenium focus issues
Selenium cannot reliably control a browser when its window is not in focus, or when you accidentally interact with the browser frame. This will result in flickering tests, which are "randomly" red and green. In fact, this behavior is not random at all and completely depends on whether or not the browser window had focus at the time.
This card will give you a better understanding of Selenium focus issues, and what you can do to get your test suite stable again.
Preventing accidental interaction with the Selenium window
--------------------...
A jQuery plugin for producing bar charts from tables.
As the title says: this jQuery plugin creates bar charts from HTML tables. It comes in some different flavors.
Check the examples page: http://alphagov.github.com/magna-charta/.
CSS: Vertically center with display: table-cell
The classical scenario: There's a parent div element and you want to center some arbitrary child element vertically inside of it. Here's how you do it (also try this jsfiddle).
The children need to be block elements.
The HTML
<div class="parent">
<div class="child"></div>
<div class="child"></div>
...
</div>
The CSS
.parent {
display: table-cell;
vertical-align: middle;
width: 500px;
height: 300px;
}
.child {}
When .child elements are inline elements, add `display: bl...
Rubygems: Rebuild native extensions
Rarely, you might want to rebuild all gems with native extensions, because they might be compiled against outdated system libraries, resulting in some warnings or even segfaults or other ruby errors.
You can do that using
gem pristine --all
This will reset all gems to a pristine state as if you'd reinstall them, and as a side effect, rebuild all native extensions.
The above command will also help you sorting out errors like this after a distribution upgrade:
libmysqlclient_r.so.16: cannot open shared object file: No such fil...
Taming icon fonts for use in Rails views
Icon fonts like Font Awesome are infinitely scalable, look great on high-DPI displays and will give your app a modern look.
However, icon fonts can be very awkward to use compared to raster icons. Elements are given icons by giving them a special class like icon-plus or icon-home:
<span class="icon-plus">Create</span>
The icon font's stylesheet will then recognize this class and insert the icon as the element's :before style.
In practic...
Rails 2.3.x sometimes renders localized views with the wrong content type
Under certain (unknown) circumstances, Rails will give localized files an invalid content-type in the Response header. For me, after requesting corporate_information and rendering corporate_information.de.html.haml, Rails sent a content-type of de.html instead of the expected text/html.
There are some discussions on this topic that offer workarounds, but no...
Waiting for page loads and AJAX requests to finish with Capybara
If you're using the Capybara webdriver, steps sometimes fail because the browser hasn't finished loading the next page yet, or it still has a pending AJAX request. You'll often see workarounds like
When I wait for the page to load
Then ...
Workarounds like this do not work reliably, will result in flickering tests and should be avoided. There is no known reliable way to detect if the browser has finished loading the page.
Solution
Instead you should wait until you can observe the result of a page load. E.g. if y...
Haml: Fix problem with HTML-escaped single quotes in text fields
Haml 3.1.2 displays single quotes in FormBuilder#text_ field html escaped. You may see something like that:
David's Chapter
Looking at the page's HTML, your field's values will be doubly escaped:
<input ... value="David&#x27;s Chapter" />
Updating Haml to 3.1.5 or newer will fix it.
Automatically strip all string fields of an ActiveRecord
If your application has forms to edit string fields, you probably want to strip the entered values (remove whitespace from beginning and end). The reason is that your users will copy + paste values from unholy places (websites, Microsoft Office) and end up having trailing whitespace in most of their records.
Because browsers ignore whitespace, no one will usually notice this until you get the weirdest bug reports (e.g. two seemingly equal records are not, or multiple records for "unique" values).
Use the attached trait in your model to hav...
Creating a Grid for Product View for a eCommerce Site
Randy Hoyt is presenting a way to display something (e.g. products) in a grid. It's responsive, too!
Get rid of WARNING: Nokogiri was built against LibXML version 2.7.7, but has dynamically loaded 2.7.8
If you get this warning on your local machine one of these steps might help:
Rebuilt the gem with the newer library
gem install --no-rdoc --no-ri nokogiri -- --with-xml2-include=/opt/local/include/libxml2 --with-xml2-lib=/opt/local/lib
If you still get the error, try to uninstall all nokogiri versions with
gem uninstall nokogiri
and install nokogiri again.
Fixing the issue on servers
However, on our servers this probably will not work. On the server, gems are stored in the ../shared/bundle/ruby/:version/gems dire...
Git basics: checkout vs. reset
Today I got a better understanding of how git works, in particular 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 at the commit you are currently working on. Usually, it is pointing to a branch which is pointing to that commit.
- Branches are nothing but pointers to commits. Y...
`simple_format` does not escape HTML tags
simple_format ignores Rails' XSS protection. Even when called with an unsafe string, HTML characters will not be escaped or stripped!
Instead simple_format calls sanitize on each of the generated paragraphs.
ActionView::Base.sanitized_allowed_tags
# => #<Set: {"small", "dfn", "sup", "sub", "pre", "blockquote", "ins", "ul", "var", "samp", "del", "h6", "h5", "h4", "h3", "h2", "h1", "span", "br", "hr", "em", "address", "img", "kbd", "tt", "a", "acrony...
Create autocompletion dropdown for Cucumber paths in Textmate
Ever wanted autocompletion for paths from paths.rb in Cucumber? This card lets you write your steps like this:
When I go to path *press tab now* # path is replaced with a list of all known Cucumber paths
This is how you do it
(key shortcuts apply for TextMate2)
-
Open the bundle editor (ctrl + alt + + B)
-
Create a new Item ( + N), select "Command"
-
Paste this:
^
#!/usr/bin/env ruby -wKU
require File.join(ENV['TM_SUPPORT_PATH'], 'lib', 'ui.rb')cucumber_paths = File.join ENV['TM_PROJECT_DIRECTORY'], 'features'...
Highlight current navigation item with Staticmatic
StaticMatic is a nice tool to build simple static websites.
In case you want to have some nifty styles on the navigation item that is currently active, you can use this:
=link 'Aktuelles', :class => (current_page =~ /aktuelles/) ? 'current' : 'default'
Keep in mind that current_page gives you the full relative path of your page. raise current_path in case you're not sure.
I know there is an navigation helper out there. I did not use it and also did not want to migrate.
How to make your application assets cachable in Rails
Note: Modern Rails has two build pipelines, the asset pipeline (or "Sprockets") and Webpacker. The principles below apply for both, but the examples shown are for Sprockets.
Every page in your application uses many assets, such as images, javascripts and stylesheets. Without your intervention, the browser will request these assets again and again on every request. There is no magic in Rails that gives you automatic caching for assets. In fact, if you haven't been paying attention to this, your application is probabl...
Test meta-refresh redirects with Cucumber
The step definition below allows you to write:
Then I should see an HTML redirect to "http://www.makandracards.com" in the page head
Capybara
Then /^I should see an HTML redirect to "([^\"]*)" in the page head$/ do |redirect_url|
page.should have_xpath("//meta[@http-equiv=\"refresh\" and contains(@content, \"#{redirect_url}\")]")
end
To find meta tags with Capybara, you can also use page.find('meta', visible: false).
"rake gettext:findpo" running forever
Under certain circumstances gettext_i18n_rails will hit a near-infinite loop. This occured in Rails 2.3.5 with Haml 3.0.18 and fast_gettext 0.5.10.
gettext_i18n_rails's Haml-Parser compiles the Haml code and delegates the parsing to ruby_parser. Unfortunately, ruby_parser appears to be confused when a string contains both escaped chars (that is, any unicode characters as ndash, umlauts etc.) and #{} blocks, which makes it extremely slow.
The easiest "solution" we came up with was to replace all occurrences of UTF-8 chars wi...
defunkt/jquery-pjax
pjax loads HTML from your server into the current page without a full reload. It's ajax with real permalinks, page titles, and a working back button that fully degrades.
pjax enhances the browsing experience - nothing more.
Fun with Ruby: Returning in blocks "overwrites" outside return values
In a nutshell: return statements inside blocks cause a method's return value to change. This is by design (and probably not even new to you, see below) -- but can be a problem, for example for the capture method of Rails.
Consider these methods:
def stuff
puts 'yielding...'
yield
puts 'yielded.'
true
end
We can call our stuff method with a block to yield. It works like t...
How to test print stylesheets with Cucumber and Capybara
A print stylesheet is easy to create. Choose a font suited for paper, hide some elements, done. Unfortunately print stylesheets often break as the application is developed further, because they are quickly forgotten and nobody bothers to check if their change breaks the print stylesheet.
This card describes how to write a simple Cucumber feature that tests some aspects of a print stylesheets. This way, the requirement of having a print stylesheet is manifested in your tests and cannot be inadvertedly removed from the code. Note that you can...