I found an unexpected issue while attempting to load a block within a magento module. The block name was *Mycompany_CustomerModule_Block_CustomerModuleDashboardDataBlock* (yes, the name is very long, but I added the module name all blocks related to the module to avoid confusing a dashboard.html with the one used by Magento Core). The issue is that, if I try to load such block, with the following command:
$this->getLayout()->createBlock('customermodule/customermoduledashboarddatablock')
Magento raises the exception "Invalid block type". I couldn't figure out what was wrong, since I copied the whole file from a block that works perfectly, and then I tried renaming the block to something shorter, such as simply DashboardDataBlock. With the shorter name, block is loaded correctly.
My question is, therefore, are there any limitations in the length of Classes' names? I can always shorten the class name, but I'd like to know if there are limits so that I can avoid having similar issues in the future. Thanks.
There could be a couple of things at play here. If you are on a case-sensitive filesystem, then the issue is that you need to match camelCasing between your filename and class ID (customermoduledashboarddatablock in your case), with the note that the first letter of any folder or file which is resoled by the autoloader will need to be uppercase regardless of class prefix or class ID. Additionally, note that PHP does not care about casing of class names and method calls - only the autoloader cares, and only on case-sensitive filesystems.
The other possible issue could be total filename length in a Windows environment.