MetricsGraphics.js
MetricsGraphics.js is a library built on top of D3 that is optimized for visualizing and laying out time-series data. It provides a simple way to produce common types of graphics in a principled, consistent and responsive way. The library currently supports line charts, scatterplots and histograms as well as features like rug plots and basic linear regression.
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How to find out what is running on a port on a remote machine
By convention, common protocols use a defined port, like 80 for HTTP or 443 for HTTPS.
You can use nmap to find out what service is running behind a given port, and most often see some details about it. This can be helpful if servers don't offe...
Best practices: Writing a Rails script (and how to test it)
A Rails script lives in lib/scripts and is run with bin/rails runner lib/scripts/.... They are a simple tool to perform some one-time actions on your Rails application. A Rails script has a few advantages over pasting some prepared code into a R...
Bash: How to grep logs for a pattern and expand it to the full request
Example
I, [2024-01-21T06:22:17.484221 #2698200] INFO -- : [4cdad7a4-8617-4bc9-84e9-c40364eea2e4] test
I, [2024-01-21T06:22:17.484221 #2698200] INFO -- : [4cdad7a4-8617-4bc9-84e9-c40364eea2e4] more
I, [2024-01-21T06:22:17.484221 #269820...
MySQL: How to create columns like "bigint" or "longtext" in Rails migrations, and what :limit means for column migrations
Rails understands a :limit options when you create columns in a migration. Its meaning depends on the column type, and sometimes the supplied value.
[The documentation](http://apidock.com/rails/ActiveRecord/ConnectionAdapters/TableDefinition/co...
Use Time.current / Date.current / DateTime.current on projects that have a time zone
Basically, you now need to know if your project uses a "real" time zone or :local, and if config.active_record.time_zone_aware_attributes is set to false or not.
- With time zones configured, always use
.currentforTime,Date, and `D...
Capistrano 2: Which Capistrano hooks to use for events to happen on both "cap deploy" and "cap deploy:migrations"
When deploying an application with "cap deploy" by default [1] you only deploy your code but do not run migrations. To avoid an application to be running with code which requires database changes that did not happen yet you should use `cap deplo...
High-level data types with "composed_of"
I recently stumbled upon the Rails feature composed_of. One of our applications dealt with a lot of addresses and they were implemented as 7 separate columns in the...
JavaScript: Testing the type of a value
Checking if a JavaScript value is of a given type can be very confusing:
- There are two operators
typeofandinstanceofwhich work very differently. - JavaScript has some primitive types, like string literals, that are not objects (as oppose...
How to find out which type of Spec you are
When you need to find out in which kind of spec you are during run-time, it's definitely possible. It's a lot easier in RSpec 2+.
For example, consider this global before block where you'd want to run some code for specific specs only:
c...
How to find out the type of a model's attribute
When you want to find out the data type of an attribute, you can just use ActiveRecord's columns_hash method.
It returns a hash of column objects that include a type attribute (and more database-related information).
Example:
Contract.c...