Step 4.6: Create font parser so we can convert 'xml' font format to 'json'

Author: DAB0mB

helpers/font_parser.js

@@ -0,0 +1,102 @@
+const _ = require("underscore");
+const Async = require("async");
+const Fs = require("fs");
+const Path = require("path");
+const { DOMParser } = require("xmldom");
+
+if (module === require.main) {
+  let fonstDir = Path.resolve(__dirname, "../resources/assets/fonts");
+  xmlsToJsons(fonstDir, err => { if (err) throw err });
+}
+
+// Gets a dir path containing font xmls and converts them all to jsons
+function xmlsToJsons(path, callback = _.noop) {
+  Fs.readdir(path, (err, files) => {
+    if (err) return callback(err);
+
+    // Remove all extensions
+    fileNames = _.uniq(files.map(file => file.split(".")[0]));
+
+    // Convert each xml individually
+    Async.each(fileNames, (fileName, next) => {
+      xmlToJson(`${path}/${fileName}`, next);
+    },
+    (err) => {
+      if (!err) console.log(
+        'All fonts have been successfully parsed!'
+      );
+
+      callback(err);
+    });
+  });
+}
+
+// Gets a font xml and converts it to json
+function xmlToJson(path, callback = _.noop) {
+  Async.waterfall([
+    (next) => {
+      Fs.readFile(`${path}.xml`, function(err, xmlBuffer) {
+        if (err) return next(err);
+
+        let json = {
+          chars: {}
+        };
+
+        let xml = xmlBuffer.toString();
+        let doc = new DOMParser().parseFromString(xml);
+        let fontDoc = doc.getElementsByTagName("Font")[0];
+        let charsDoc = fontDoc.getElementsByTagName("Char");
+
+        // Compose meta-data about font like size and family
+        _.each(fontDoc.attributes, (attr) => {
+          json[attr.name] = parseInt(attr.value) || attr.value;
+        });
+
+        // Compose data about each character in font
+        _.each(charsDoc, (charDoc) => {
+          let charCode = charDoc.getAttribute("code");
+
+          let char = json.chars[charCode] = {
+            rect: rect = {},
+            offset: offset = {},
+            width: parseInt(charDoc.getAttribute("width"))
+          };
+
+          [
+            rect.x,
+            rect.y,
+            rect.width,
+            rect.height
+          ] = extractIntegers(charDoc.getAttribute("rect"));
+
+          [offset.x, offset.y] = extractIntegers(charDoc.getAttribute("offset"));
+        });
+
+        next(null, JSON.stringify(json, null, 2));
+      });
+    },
+    (json, next) => {
+      // Once finished, write json into file
+      Fs.writeFile(path + ".json", json, (err) => {
+        next(err);
+      });
+    }
+  ], (err) => {
+    if (!err) console.log(
+      `Font ${path} has been successfully parsed...`
+    );
+
+    callback(err);
+  });
+};
+
+// Converts an string of numbers to array of numbers
+// e.g. extractIntegers("1 2 3") -> [1, 2, 3]
+function extractIntegers(srcstr) {
+  return srcstr.split(" ").map((substr) => parseInt(substr));
+}
+
+module.exports = {
+  xmlToJson,
+  xmlsToJsons
+};