/epoch

A general purpose, real-time visualization library.

Primary LanguageHTMLMIT LicenseMIT

Epoch

By Ryan Sandor Richards

Epoch is a general purpose charting library for application developers and visualization designers. It focuses on two different aspects of visualization programming: basic charts for creating historical reports, and real-time charts for displaying frequently updating timeseries data.

To get started using Epoch, please refer to the Epoch Project Site. There you can find full documentation and guides to help you start using Epoch right away.

Installation

There are two easy options you can use to install epoch. The first is to use bower from the command-line, like so:

bower install epoch

The second is to visit the project site, download the latest release, and manually install it in your project. Both methods will provide you with the epoch.min.js and epoch.min.css files, simply include them along with d3 in your page and you're ready to go.

Important: Epoch requires d3. In order to work properly your page must load d3 before epoch.

Developing Epoch

Developing Epoch is a reasonably straight forward process. In this section we'll cover the basic on how to develop Epoch by detailing common build task, exploring how the source is arranged, and finally show how to use rendering tests to aid development.

Configuring Development Environment

Epoch uses several tools in its development:

  1. CoffeeScript (required)
  2. node-sass (required, needed for compiling SCSS to CSS)
  3. node-minify (optional, needed for building a minified release)
  4. codo (optional, needed for generating documentation)

All of the above tools can be installed via npm. After cloning the repository, run npm install in the project directory to install the above requirements.

Basic Development Process

The best way to start contributing to Epoch is to follow these steps:

  1. Change to the source directory for the project
  2. Run cake build to build the JavaScript and CSS from source
    1. Optionally run cake documentation to compile the API documentation into HTML
  3. In a web browser open the test/index.html and browse the rendering tests
  4. Make changes in the CoffeeScript Source and use cake build or cake watch so that your changes are compiled
  5. Use the rendering tests to see if your changes had the desired result
  6. Ensure unit tests with pass cake test

Testing

Epoch uses two types of testing to ensure that changes do not cause unintended side effects. The first, unit tests, ensure that the core functional components of the library work as expected. The second, rendering tests, allow you to ensure that charts and graphs are correctly rendered.

It is important to keep both unit test and rendering tests up-to-date! When developing, use the following guidelines:

  • When adding new features make sure to add new tests
  • When changing existing functionality, ensure that the appropriate both types of tests still pass
  • If you want to make a new type of chart, add a whole new test suite for that chart!

Keeping the tests current makes it easier for others to review your code and spot issues. Also, pull requests without appropriate testing will not be merged... period.

Build Tasks

Epoch uses cake for its builds. The file defines the following tasks:

Cakefile defines the following tasks:

cake build                # Builds JavaScript and CSS from source (also packages)
cake coffee               # Compiles JavaScript from CoffeeScript source
cake sass                 # Compiles SASS source into CSS
cake package              # Packages the JavaScript into a single file
cake compile              # Compiles the packaged source via the Google Closure Compiler
cake watch
cake documentation        # Compiles API documentation
cake test                 # Runs unit tests
cake release              # Releases a new version of the library
cake clean                # Removes build files completely

  -v, --version      Sets the version number for the release task

For the most part you'll only need to use the following tasks:

  1. cake build / cake watch - These will compile the CoffeeScript into JavaScript and compile SCSS to CSS.
  2. cake --version X.Y.Z release - This is used to create minified release versions of the library.

Source Structure

The directory structure for the Epoch project follows some basic guidelines, here's an overview of how it is structured:

src/                   - Main source directory
  core/                - Core Epoch Library Files
    util.coffee        - Library Utility Routines
    d3.coffee          - d3 Extensions
    format.coffee      - Data formatters
    chart.coffee       - Base Chart Classes
    css.coffee         - CSS Querying Engine
  adapters/            - 3rd Party Library Adapters (currently only jQuery)
  basic/               - Basic Chart Classes
  time/                - Real-time Chart Classes
  adapters.coffee      - Options / Global Classes for Adapter Implementations
  basic.coffee         - Base Classes for Basic Charts
  data.coffee          - Data Formatting
  epoch.coffee         - Main source file, defines name spaces, etc.
  model.coffee         - Data Model
  time.coffee          - Base Classes for Real-Time Charts
lib/                   - "Baked in" libraries
sass/                  - Scss source for the default epoch stylesheet
tests/
  render/              - Rendering tests
    basic/             - Basic chart rendering tests
    real-time/         - Real-time rendering tests
  unit/                - Unit tests

Release Checklist

  • Update CHANGELOG.md with the changes since last release
  • Run cake test and ensure all tests pass
  • Run cake release to generate new minified JS and CSS
  • Copy new .zip of release source files to gh-pages branch
  • Update the website's library version in the _config.yml
  • Update the website's copy of Epoch

Copyright / Legal

The MIT License (MIT)

Copyright (c) 2014 Fastly, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.