Acquired Opera AdBlock code

files/preferences.js

Index: files/preferences.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/files/preferences.js
@@ -0,0 +1,83 @@
+const preferences = {
+	string: function(key, value) { //Gets or sets a string value
+		if(value == undefined) //Gets

[Felix Dahlke, 2012/10/08 05:57:02]

That's a bit dangerous, undefined could in fact have been defined. Better:
typeof value === "undefined"

+			return widget.preferences.getItem(key);
+		else //Sets
+			widget.preferences.setItem(key, value);
+	},
+	bool: function(key, value) { //Gets or sets a bool value
+		if(value == undefined) { //Gets

[Felix Dahlke, 2012/10/08 05:57:02]

See comment about the same code above.

+			switch(widget.preferences.getItem(key)) {

[Felix Dahlke, 2012/10/08 05:57:02]

How about return key === "true" instead?

+				case 'true':
+					return true;
+					break;
+				default: //Returns false if the value doesn't exist
+					return false;
+					break;
+			}
+		}
+		else { //Sets
+			if(value)
+				widget.preferences.setItem(key, 'true');
+			else
+				this.remove(key); //When set to false, remove the key to save space
+		}
+	},
+	int: function(key, value) { //Gets or sets a int value
+		if(value == undefined) { //Gets

[Felix Dahlke, 2012/10/08 05:57:02]

See comment about the same code above.

+			value = parseInt(widget.preferences.getItem(key));
+			if(value == NaN)

[Felix Dahlke, 2012/10/08 05:57:02]

No, this doesn't work. Use isNan().

+				return 0; //On error return 0

[Felix Dahlke, 2012/10/08 05:57:02]

I think it's dangerous to return 0 in case of an error - is there never a
situation where we want to distinguish a not stored value from the explicit
value 0?

+			else
+				return value;
+		}
+		else //Sets
+			widget.preferences.setItem(key, value);
+	},
+	float: function(key, value) { //Gets or sets a float value
+		if(value == undefined) { //Gets

[Felix Dahlke, 2012/10/08 05:57:02]

See comment about the same code above.

+			value = parseFloat(widget.preferences.getItem(key));
+			if(value == NaN)

[Felix Dahlke, 2012/10/08 05:57:02]

See above, use isNan()

+				return 0; //On error return 0

[Felix Dahlke, 2012/10/08 05:57:02]

See above, not sure if this is a good idea.

+			else
+				return value;
+		}
+		else //Sets
+			widget.preferences.setItem(key, value);
+	},
+	array: function(key, value) { //Gets or sets an array in the preferences
+		if(value == undefined) { //Gets

[Felix Dahlke, 2012/10/08 05:57:02]

See comment about the same code above.

+			if(this.exist(key)) {
+				value = widget.preferences.getItem(key);
+				if(value.indexOf("\n") > -1)

[Felix Dahlke, 2012/10/08 05:57:02]

This whole if/else can be replaced by: return value.split("\n")

+					return value.split("\n");
+				else {
+					return [value];
+				}
+			}
+			return new Array(); //Returns an empty array when no value exists

[Felix Dahlke, 2012/10/08 05:57:02]

Shorter: return []

+		}
+		else if(value instanceof Array) { //Sets
+			value = value.join("\n");
+			widget.preferences.setItem(key, value);
+		}
+	},
+	invert: function(key) { //Inverts a true/false setting
+		switch(widget.preferences.getItem(key)) {

[Felix Dahlke, 2012/10/08 05:57:02]

This switch can be replaced with: widget.preferences.setItem(key, item ===
'true' ? 'false' : 'true')

+			case 'true':
+				widget.preferences.setItem(key, 'false');
+				break;
+			default:
+				widget.preferences.setItem(key, 'true');
+				break;
+		}
+	},
+	exist: function(key) { //Says if a preference exists

[Felix Dahlke, 2012/10/08 05:57:02]

This will return false for a numerical value set to 0, see above. Considering
that, we can just write: return !!widget.preferences.getItem(key).

This also avoids getItem being called twice.

+		if(widget.preferences.getItem(key) != null && widget.preferences.getItem(key) != '')
+			return true;
+		return false;
+	},
+	remove: function(key) {
+		widget.preferences.removeItem(key);
+	}
+};