Support all render options in auto-render.

Closes #690.

contrib/auto-render/README.md

@@ -55,7 +55,9 @@ function renderMathInElement(elem, options)
 `elem` is an HTML DOM element. The function will recursively search for text
 nodes inside this element and render the math in them.
 
-`options` is an optional object argument with the following keys:
+`options` is an optional object argument that can have the same keys as [the 
+object passed to `katex.render`](https://github.com/Khan/KaTeX/#rendering-options),
+in addition to two auto-render-specific keys:
 
 - `delimiters`: This is a list of delimiters to look for math. Each delimiter
   has three properties:
@@ -78,3 +80,7 @@ nodes inside this element and render the math in them.
 - `ignoredTags`: This is a list of DOM node types to ignore when recursing
   through. The default value is
   `["script", "noscript", "style", "textarea", "pre", "code"]`.
+
+Note that the `displayMode` property of the options object is ignored, and is 
+instead taken from the `display` key of the corresponding entry in the 
+`delimiters` key.

contrib/auto-render/auto-render.js

@@ -14,8 +14,11 @@ const splitWithDelimiters = function(text, delimiters) {
     return data;
 };
 
-const renderMathInText = function(text, delimiters) {
+/* Note: optionsCopy is mutated by this method. If it is ever exposed in the
-    const data = splitWithDelimiters(text, delimiters);
+ * API, we should copy it before mutating.
+ */
+const renderMathInText = function(text, optionsCopy) {
+    const data = splitWithDelimiters(text, optionsCopy.delimiters);
 
     const fragment = document.createDocumentFragment();
 
@@ -25,10 +28,11 @@ const renderMathInText = function(text, delimiters) {
         } else {
             const span = document.createElement("span");
             const math = data[i].data;
+            // Override any display mode defined in the settings with that
+            // defined by the text itself
+            optionsCopy.displayMode = data[i].display;
             try {
-                katex.render(math, span, {
+                katex.render(math, span, optionsCopy);
-                    displayMode: data[i].display,
-                });
             } catch (e) {
                 if (!(e instanceof katex.ParseError)) {
                     throw e;
@@ -48,28 +52,28 @@ const renderMathInText = function(text, delimiters) {
     return fragment;
 };
 
-const renderElem = function(elem, delimiters, ignoredTags) {
+const renderElem = function(elem, optionsCopy) {
     for (let i = 0; i < elem.childNodes.length; i++) {
         const childNode = elem.childNodes[i];
         if (childNode.nodeType === 3) {
             // Text node
-            const frag = renderMathInText(childNode.textContent, delimiters);
+            const frag = renderMathInText(childNode.textContent, optionsCopy);
             i += frag.childNodes.length - 1;
             elem.replaceChild(frag, childNode);
         } else if (childNode.nodeType === 1) {
             // Element node
-            const shouldRender = ignoredTags.indexOf(
+            const shouldRender = optionsCopy.ignoredTags.indexOf(
                 childNode.nodeName.toLowerCase()) === -1;
 
             if (shouldRender) {
-                renderElem(childNode, delimiters, ignoredTags);
+                renderElem(childNode, optionsCopy);
             }
         }
         // Otherwise, it's something else, and ignore it.
     }
 };
 
-const defaultOptions = {
+const defaultAutoRenderOptions = {
     delimiters: [
         {left: "$$", right: "$$", display: true},
         {left: "\\[", right: "\\]", display: true},
@@ -83,30 +87,14 @@ const defaultOptions = {
     ],
 };
 
-const extend = function(obj) {
-    // Adapted from underscore.js' `_.extend`. See LICENSE.txt for license.
-    let source;
-    let prop;
-    const length = arguments.length;
-    for (let i = 1; i < length; i++) {
-        source = arguments[i];
-        for (prop in source) {
-            if (Object.prototype.hasOwnProperty.call(source, prop)) {
-                obj[prop] = source[prop];
-            }
-        }
-    }
-    return obj;
-};
-
 const renderMathInElement = function(elem, options) {
     if (!elem) {
         throw new Error("No element provided to render");
     }
 
-    options = extend({}, defaultOptions, options);
+    const optionsCopy = Object.assign({}, defaultAutoRenderOptions, options);
 
-    renderElem(elem, options.delimiters, options.ignoredTags);
+    renderElem(elem, optionsCopy);
 };
 
 module.exports = renderMathInElement;