Talk:GM.getValue: Difference between revisions
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:If the desired behavior is to return undefined, it will need to be corrected in the trunk as well as a.m.o. | :If the desired behavior is to return undefined, it will need to be corrected in the trunk as well as a.m.o. | ||
---- | |||
Try something along the lines of | |||
<pre> | |||
// ==UserScript== | |||
// @name GetSetValueTest | |||
// @description Tests the behaviour of gm_getValue for a missing property | |||
// @include http://www.example.com/ | |||
// ==/UserScript== | |||
var val = GM_getValue("missingProperty"); | |||
var msg = "val: " + val + "\n" | |||
+ "typeof(val): " + typeof(val) + "\n" | |||
+ "val==undefined: " + (val==undefined) + "\n" | |||
+ "val===undefined: " + (val===undefined) + "\n" | |||
+ "val==null: " + (val==null) + "\n" | |||
+ "val===null: " + (val===null) + "\n"; | |||
alert(msg) | |||
</pre> | |||
I get: | |||
<pre> | |||
val: undefined | |||
typeof(val): undefined | |||
val==undefined: true | |||
val===undefined: true | |||
val==null: true | |||
val===null: false | |||
</pre> | |||
I believe (but haven't tested) that [http://greasemonkey.devjavu.com/browser/trunk/src/chrome/chromeFiles/content/prefmanager.js#L36 lines 36-38] returns defaultValue (i.e undefined) and lines 50 and 52 are never executed. | |||
<pre> | |||
if (prefType == pref.PREF_INVALID) { | |||
return defaultValue; | |||
} | |||
</pre> | |||
--[[User:Gingerhendrix|Gingerhendrix]] 21:13, 6 January 2008 (EST) |
Revision as of 02:13, 7 January 2008
- Ref: 0.7.20070607.0 Release on a.m.o prefmanager.js
- Line 49
return null;
- Ref: Current trunk as of 2007 01 03 prefmanager.js
- Line 52
return null;
- There is a difference between null and undefined.
null
is an object (e.g.alert(typeof(null));
)undefined
has no memory allocated (e.g.alert(typeof(undefined));
)
- If the desired behavior is to return undefined, it will need to be corrected in the trunk as well as a.m.o.
Try something along the lines of
// ==UserScript== // @name GetSetValueTest // @description Tests the behaviour of gm_getValue for a missing property // @include http://www.example.com/ // ==/UserScript== var val = GM_getValue("missingProperty"); var msg = "val: " + val + "\n" + "typeof(val): " + typeof(val) + "\n" + "val==undefined: " + (val==undefined) + "\n" + "val===undefined: " + (val===undefined) + "\n" + "val==null: " + (val==null) + "\n" + "val===null: " + (val===null) + "\n"; alert(msg)
I get:
val: undefined typeof(val): undefined val==undefined: true val===undefined: true val==null: true val===null: false
I believe (but haven't tested) that lines 36-38 returns defaultValue (i.e undefined) and lines 50 and 52 are never executed.
if (prefType == pref.PREF_INVALID) { return defaultValue; }
--Gingerhendrix 21:13, 6 January 2008 (EST)