Create an Exception for a missing component

[mbabker]

Summary of Changes

The base Exception class really shouldn't be thrown, it's too generic and gets caught by too many try/catch blocks. Good practice is to use more specialized exceptions.

In JComponentHelper::renderComponent() an Exception is thrown if the component is missing (either the option parameter is empty, the component is disabled, or the entry point file doesn't exist in the filesystem). I've created a new JComponentExceptionMissing class to represent this error state instead.

Testing Instructions

A request for a non-existing or disabled component should result in a JComponentExceptionMissing object being thrown versus the base level Exception.

Documentation Changes Required

N/A

[Thoert]

I have tested this item ✅ successfully on 267b142

Work as expected.

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/13919.}

[wilsonge]

I think we should make the default code of the exception should be 404 if it's a component missing

[wilsonge]

Looks good now :)