no more client-side mathjax

lib/latex-loader.js

@@ -1,3 +1,8 @@
+var sha1 = require("sha1");
+var fs = require("fs");
+
+var execSync = require("child_process").execSync;
+
 var op = "\\[";
 var ed = "\\]";
 
@@ -25,8 +30,22 @@ function escapeBlockLaTeX(source) {
       throw new Error("improperly closed LaTeX encountered!");
     }
     latex = source.substring(curr, term + ed.length);
-    latex = latex.replace(/([{}])/g,"{'$1'}");
-    newsource += latex;
+
+    // convert this LaTeX code into an SVG file in ./images/latex,
+    // using mathjax-node in the ./tools directory
+    var hash = sha1(latex);
+    var filename = "images/latex/" + hash + ".svg";
+    var destination = __dirname + "/../" + filename;
+    var rewrite = '<img className="LaTeX SVG" src="/' + filename + '"/>';
+
+    // And only generate if the file doesn't already exist, of course.
+    if (!fs.existsSync(destination)) {
+      var cmdarg = new Buffer(latex).toString("base64");
+      var cmd = "npm run latex -- --hash " + hash + " --base64 " + cmdarg;
+      execSync(cmd);
+    }
+
+    newsource += rewrite;
   }
   return newsource + source.substring(from);
 }