Issue 241 - Support for update(options) where options will extend current options

README.md

@@ -152,11 +152,13 @@ customSectors: {
     color : "#43bf58",
     lo : 0,
     hi : 50
-  },{
+  },
+  {
     color : "#ff3b30",
     lo : 51,
     hi : 100
   }]
+}
 ```
 
 ### Pointer options
@@ -181,18 +183,42 @@ pointerOptions: {
 
 Used to refresh Gauge value and max value
 
-`refresh(val, max, min, label)`
+`guage.refresh(val, max, min, label)`
 
 - `val` : The Gauge value (required)
 - `max` : The Gauge Max value (optional)
 - `min` : The Gauge Min value (optional)
 - `label` : The Gauge label text (optional)
 
+### Update
+
+Used to dynamically update existing Gauge appearence
+
+`gauge.update(option, value)`
+
+vs
+
+```js
+const options = {
+  valueFontColor: '#ff0000',
+  labelFontColor: '#ff0000',
+}
+gauge.update(options)
+```
+
+#### Options
+
+| Name                 | Description                                 |
+| -------------------- | ------------------------------------------- |
+| valueFontColor       | HEX color for gauge value text              |
+| labelFontColor       | HEX color for gauge min, max and label text |
+
+
 ### Destroy
 
 Used to destroy the Gauge element
 
-`destroy()`
+`guage.destroy()`
 
 ## Demo
 

justgage.js

@@ -996,6 +996,73 @@
     obj, displayVal, color, max, min = null;
   };
 
+  /**
+   * Update Gauge options
+   *
+   * @param options {String} option The target option name
+   * @param val {Number|String} val The value to be assigned to the option
+   *
+   * Alternative signature
+   * @param options {String|Object} options name and value
+   */
+  JustGage.prototype.update = function (options, val) {
+    const obj = this;
+
+    // options as an object of option/val values
+    if (options instanceof Object) {
+      for (var option in options) {
+        val = options[option];
+        updateProp(obj, option, val);
+      }
+
+    // options as single option/val
+    } else {
+      updateProp(obj, options, val);
+    }
+  };
+
+  /**
+   * Utility function to update properties to a JustGage object
+   *
+   * @param obj {JustGage Object} JustGage object to apply the property update to
+   * @param option {String} option name
+   * @param val {String} option value
+   */
+  function updateProp(obj, option, val) {
+    switch (option) {
+      case 'valueFontColor':
+        if (!isHexNumber(val)) {
+          console.log('* justgage: the updated valueFontColor value is not a valid hex value');
+          break;
+        }
+
+        obj.txtValue.attr({
+          'fill': val
+        });
+        break;
+
+      case 'labelFontColor':
+        if (!isHexNumber(val)) {
+          console.log('* justgage: the updated labelFontColor value is not a valid hex value');
+          break;
+        }
+
+        obj.txtMin.attr({
+          "fill": val,
+        });
+        obj.txtMax.attr({
+          "fill": val,
+        });
+        obj.txtLabel.attr({
+          "fill": val,
+        });
+
+        break;
+
+      default:
+        console.log(`* justgage: "${option}" is not a supported update setting`);
+    }
+  }
 
   /**
    * Destroy the Gauge Object and unbind events
@@ -1011,7 +1078,6 @@
     this.events = {}
   };
 
-
   /**
    * Generate Shadow
    *
@@ -1201,6 +1267,17 @@
     return (str.charAt(0) == "#") ? str.substring(1, 7) : str;
   }
 
+  /**
+   * Validate if hex value
+   *
+   * @param val
+   * @returns {*|boolean}
+   */
+  function isHexNumber(val) {
+    var regExp = /^[-+]?[0-9A-Fa-f]+\.?[0-9A-Fa-f]*?$/;
+    return (typeof val === 'string' && regExp.test(val));
+  }
+
   /**  Human friendly number suffix - @robertsLando */
   function humanFriendlyNumber(n, d) {
     var d2, i, s, c;
@@ -1299,9 +1376,3 @@
 
   return JustGage
 }));
-
-
-
-
-
-