Perseus is Khan Academy's new exercise question editor and renderer. It allows you to create and display interactive questions.
Our test page isn't much yet, but you can check out a live demo of it here!
To get the dev server running locally, try make server PORT=9000
which will run the local perseus server on localhost:9000.
Then visit http://localhost:9000/.
To package perseus for distribution, run make build and to package a debug-friendly build, run make debug.
Both the build and the server make targets will run npm install but you can also run it yourself to install all node dependencies.
Perseus uses two types of version numbers: the version of the itemData/content
that can be sent to ItemRenderer/Renderer, and the version of the api
exposed through the ItemRenderer/Renderer apiOptions prop. These
are set in src/version.json.
Item data versioning has two subtypes of versions: a global itemDataVersion
for the itemData/content format sent to ItemRenderer/Renderer, and per-widget
version numbers for the options sent to each widget. All of these version
numbers exist both in perseus.js and in the itemData saved to the datastore
by the Perseus editor.
Each of these versions consists of a major and minor version number.
A perseus version can render an itemData version iff its global
itemDataVersion and each of its widget versions are greater than or equal
to those sent to perseus as itemData. A major version increase will happen
when the saving format of this itemData has changed. Perseus clients should
not need to care about this distinction, but it is important to Perseus'
implementation of backwards-compatibility.
The version of the apiOptions prop sent to ItemRenderer or Renderer
is stored on Perseus.apiVersion. A minor version increase indicates an
optional additional parameter to this interface. A major version increase
indicates a not-backwards-compatible change to this API. A perseus client
should rely on a specific major version of perseus, and should be able to
use any future minor version increase without changes, but not necessarily
previous minor versions. For example, if a client begins using version 1.2,
Perseus api versions 1.3 or 1.4 will work transparently, but Perseus api
versions 1.0, 1.1, 2.0, or 2.2 will not work.
See CONTRIBUTING.md for a walkthrough of how some of the Perseus code works and how to extend it.