Allow macros to be persisted using state

Author: rianmcguire

lib/main.js

@@ -742,12 +742,18 @@ function GetState(state) {
     MathJax.OutputJax.CommonHTML.ID = 0;
   }
 
-  // Clear any existing user defined macros
+  // Clear any existing user defined macros, then load macros from state
   Object.keys(TEX.Definitions.macros).forEach(function(macroName){
     if (TEX.Definitions.macros[macroName].isUser) {
       delete TEX.Definitions.macros[macroName];
     }
   });
+  if (state && state.macros) {
+    for (var macroName in state.macros) {
+      TEX.Definitions.macros[macroName] = state.macros[macroName];
+      TEX.Definitions.macros[macroName].isUser = true;
+    }
+  }
 }
 
 //
@@ -772,6 +778,7 @@ function ReturnResult(result) {
   if (state) {
     var AMS = MathJax.Extension["TeX/AMSmath"];
     var GLYPH = MathJax.OutputJax.SVG.BBOX.GLYPH;
+    var TEX = MathJax.InputJax.TeX;
     state.AMS.startNumber = AMS.startNumber;
     state.AMS.labels = AMS.labels;
     state.AMS.IDs = AMS.IDs;
@@ -780,6 +787,13 @@ function ReturnResult(result) {
     state.defs = GLYPH.defs;
     state.n = GLYPH.n;
     state.ID = ID;
+    state.macros = {};
+    for (var macroName in TEX.Definitions.macros) {
+      var macro = TEX.Definitions.macros[macroName];
+      if (macro.isUser) {
+        state.macros[macroName] = macro;
+      }
+    }
   }
   serverState = STATE.READY;
   callback(result, originalData);

test/macro-state.js

@@ -21,3 +21,40 @@ tape('macros should be cleared from global state', function(t) {
     t.true(data.errors, '\\mymacro should no longer be defined');
   });
 });
+
+tape('macros can be persisted using state option', function(t) {
+  t.plan(4);
+  mjAPI.start();
+
+  var state = {};
+
+  mjAPI.typeset({
+    math: "\\def\\mymacro{2\\pi} \\mymacro",
+    format: "TeX",
+    mml: true,
+    state: state
+  }, function(data) {
+    t.false(data.errors, 'Defined and used macro');
+    t.equal(Object.keys(state.macros).length, 1, 'Only stores the user defined macro in state');
+
+    // Ensure state contains only serializable data
+    state = JSON.parse(JSON.stringify(state));
+
+    mjAPI.typeset({
+      math: "\\mymacro",
+      format: "TeX",
+      mml: true,
+      state: state
+    }, function(data) {
+      t.false(data.errors, '\\mymacro was not persisted in state');
+    });
+
+    mjAPI.typeset({
+      math: "\\mymacro",
+      format: "TeX",
+      mml: true,
+    }, function(data) {
+      t.true(data.errors, '\\mymacro should no longer be defined if state is not provided');
+    });
+  });
+});