The MathJax.InputJax Class¶
Input jax are the components of MathJax that translate mathematics from its original format (like TeX or MathML) to the MathJax internal format (an element jax).
An input jax is stored as a pair of files in a subdirectory of the
jax/input
directory, with the subdirectory name being the name of
the input jax. For example, the TeX input jax is stored in
jax/input/TeX. The first file, config.js
, is loaded when
MathJax is being loaded and configured, and is indicated by listing
the input jax directory in the jax array of the MathJax
configuration. The config.js
file creates a subclass of the
MathJax.InputJax object for the new input jax and registers that
with MathJax, along with the MIMEtype that will be used to indicate
the mathematics that is to be processed by the input jax.
The main body of the input jax is stored in the second file,
jax.js
, which is loaded when the input jax is first called on to
translate some mathematics. This file augments the original input jax
subclass with the additional methods needed to do the translation.
MathJax calls the input jax’s Translate()
method when it needs
the input jax to translate the contents of a math <script>
tag.
The MathJax.InputJax class is a subclass of the MathJax Jax class, and inherits the properties and methods of that class. Those listed below are the additional or overridden ones from that class.
Properties¶

id
The name of the jax.

version
The version number of the jax.

directory
The directory where the jax files are stored (e.g.,
"[MathJax]/jax/input/TeX"
).

elementJax
The name of the ElementJax class that this input jax will produce (typically
mml
, as that is the only ElementJax at the moment).
Methods¶

Process
(script, state) This is the method that the
MathJax.Hub
calls when it needs the input jax to process the given math<script>
. Its default action is to do the following: Start loading any element jax specified in the
elementJax
array;  Start loading the jax’s
jax.js
file;  Start loading the required output jax (so it is ready when needed); and
 Redefine itself to simply return the callback for the load operation (so that further calls to it will cause the processing to wait for the callback).
Once the
jax.js
file has loaded, this method is replaced by the jax’sTranslate()
method (see below), so that subsequent calls toProcess()
will perform the appropriate translation.Parameters:  script — reference to the DOM
<script>
object for the mathematics to be translated  state — a structure containing information about the current proccessing state of the mathematics (internal use)
Returns: an ElementJax object, or
null
 Start loading any element jax specified in the

Translate
(script, state) This is the main routine called by MathJax when a
<script>
of the appropriate type is found. The defaultTranslate()
method throws an error indicating thatTranslate()
hasn’t been defined, so when thejax.js
file loads, it should override the defaultTranslate()
with its own version that does the actual translation.The translation process should include the creation of an Element Jax that stores the data needed for this element.
Parameters:  script — the
<script>
element to be translated  state — a structure containing information about the current proccessing state of the mathematics (internal use)
Returns: the element jax resulting from the translation
 script — the

Register
(mimetype) This registers the MIMEtype associated with this input jax so that MathJax knows to call this input jax when it sees a
<script>
of that type. An input jax can register more than one type, but it will be responsible for distinguishing elements of the various types from one another.Parameters:  mimetype — the MIMEtype of the input this jax processes
Returns: null

needsUpdate
(jax) This implements the element jax’s
needsUpdate()
method, and returnstrue
if thejax
needs to be rerendered (i.e., the text has changed), andfalse
otherwise.Perameters:  jax — the element jax to be checked
Returns: true
if the jax’s text has changed,false
otherwise