Fix retrieving style values in node.js

src/c3.axis.js

@@ -172,7 +172,7 @@ function c3_axis(d3, params, $$) {
             tspan.enter().append('tspan');
             tspan.exit().remove();
 
-            var fontSize = parseFloat(getStyleValue('.c3-axis-y .tick', 'font-size'));
+            var fontSize = parseFloat(getStyleValue($$, '.c3-axis-y .tick', 'font-size'));
                 
             tspan.text(function (d) {
                 if (d.splitted.length) {

src/core.js

+var __filename; // used in Node.js to get css file using path
+var c3_chart_fn, c3_chart_internal_fn;
 var c3 = { version: "0.4.9" };
 
-var c3_chart_fn, c3_chart_internal_fn;
+var c3init = function(module){
+    __filename = module.uri;
+    return c3;
+}
 
 function Chart(config) {
     var $$ = this.internal = new ChartInternal(this);
@@ -43,9 +48,52 @@ c3_chart_fn = c3.chart.fn;
 c3_chart_internal_fn = c3.chart.internal.fn;
 
 
+var nodeCss;
+var styleCache = {};
+
 // Seek a specific value in the stylesheets of a document
-function getStyleValue(selector, property) {
+function getStyleValue($$, selector, property) {
+    function cache(value){
+        if(!styleCache[selector]){
+            styleCache[selector] = {};
+        }
+        styleCache[selector][property] = value.trim();
+        return styleCache[selector][property];
+    }
+
+    if(styleCache[selector] && styleCache[selector][property]){
+        return styleCache[selector][property];
+    }
+
     var css, rule, sheet, value;
+    if(isNode()){
+        if(!nodeCss){
+            var style = require('fs').readFileSync(__filename.replace('c3.js', 'c3.css'), 'utf-8');
+            nodeCss = [require('css').parse(style), require('css').parse($$.ed3Config.style)];
+        }
+
+        var obj, rule, sel, decl;
+
+        for(var i = 0; i<nodeCss.length; i++){
+            obj = nodeCss[i];
+            for(var j = 0; j<obj.stylesheet.rules.length; j++){
+                rule = obj.stylesheet.rules[j];
+                if(!rule.selectors) continue;
+                for(var k = 0; k<rule.selectors.length; k++){
+                    sel = rule.selectors[k];
+                    for(var l = 0; l<rule.declarations.length; l++){
+                        decl = rule.declarations[l];
+                        if(decl.property === property){
+                            return cache(decl.value);
+                        }
+                    }
+                }
+            }
+        }
+
+        console.log('Style not found: ', selector, '->', property);
+        return undefined;
+    }
     for (var styleId = 0; styleId < document.styleSheets.length; styleId++) {
         sheet = document.styleSheets[styleId];
         for (var ruleId = 0; ruleId < sheet.cssRules.length; ruleId++) {
@@ -55,7 +103,7 @@ function getStyleValue(selector, property) {
                 if (css.indexOf(property) !== -1) {
                     try {
                         value = css.split(property)[1].split(':')[1].split(';')[0];
-                        return value.trim();
+                        return cache(value);
                     } catch (e) {
                         // Error will be caught in case of incorrect CSS
                         return undefined;

src/legend.js

@@ -132,7 +132,7 @@ c3_chart_internal_fn.updateLegend = function (targetIds, options, transitions) {
     var hasFocused = $$.legend.selectAll('.' + CLASS.legendItemFocused).size();
     var texts, rects, tiles, background;
 
-    var nodeOffset = isNode() ? 3 : 1;
+    var nodeOffset = 1;
 
     options = options || {};
     withTransition = getOption(options, "withTransition", true);

src/tail.js

     if (typeof define === 'function' && define.amd) {
-        define("c3", ["d3"], c3);
+        define("c3", ["module", "d3"], c3init);
     } else if ('undefined' !== typeof exports && 'undefined' !== typeof module) {
         module.exports = c3;
     } else {

src/text.js

@@ -48,7 +48,7 @@ c3_chart_internal_fn.redrawText = function (xForText, yForText, forFlow, withTra
     ];
 };
 c3_chart_internal_fn.getTextRect = function (text, cls) {
-    var fontSize = parseFloat(getStyleValue(cls, 'font-size'));
+    var fontSize = parseFloat(getStyleValue(this, cls, 'font-size'));
         
     return {
         height: fontSize,