36 lines
1.4 KiB
JavaScript
36 lines
1.4 KiB
JavaScript
/* This file defines a processor in between the student's math input
|
|
(AsciiMath) and what is read by MathJax. It allows for our own
|
|
customizations, such as use of the syntax "a_b__x" in superscripts, or
|
|
possibly coloring certain variables, etc&.
|
|
|
|
It is used in the <textline> definition like the following:
|
|
|
|
<symbolicresponse expect="a_b^c + b_x__d" size="30">
|
|
<textline math="1"
|
|
preprocessorClassName="SymbolicMathjaxPreprocessor"
|
|
preprocessorSrc="/static/js/capa/symbolic_mathjax_preprocessor.js"/>
|
|
</symbolicresponse>
|
|
*/
|
|
window.SymbolicMathjaxPreprocessor = function() {
|
|
this.fn = function(eqn) {
|
|
// flags and config
|
|
var superscriptsOn = true;
|
|
|
|
if (superscriptsOn) {
|
|
// find instances of "__" and make them superscripts ("^") and tag them
|
|
// as such. Specifcally replace instances of "__X" or "__{XYZ}" with
|
|
// "^{CHAR$1}", marking superscripts as different from powers
|
|
|
|
// a zero width space--this is an invisible character that no one would
|
|
// use, that gets passed through MathJax and to the server
|
|
var c = '\u200b';
|
|
eqn = eqn.replace(/__(?:([^\{])|\{([^\}]+)\})/g, '^{' + c + '$1$2}');
|
|
|
|
// NOTE: MathJax supports '\class{name}{mathcode}' but not for asciimath
|
|
// input, which is too bad. This would be preferable to this char tag
|
|
}
|
|
|
|
return eqn;
|
|
};
|
|
};
|