Q:

How to save a global set’s content? 

I’m trying to set data within a global set.  I’ve tried the following without success:
$globalSetHandle = 'settings';
$globalSet = craft()->globals->getSetByHandle($globalSetHandle);

$globalSet->fieldHandle = 'value';

craft()->globals->saveContent(GlobalSetModel $globalSet);

A:

Try using setContentFromPost, as mentioned in this answer from Brandon. 
$content = array(
    'fieldHandle' => 'value',
);

$globalSet->setContentFromPost($content);
craft()->globals->saveContent($globalSet);

