Change file path for saving image to be optional

[dmyers]

It looks like the save() function for images requires a file path.
https://github.com/avalanche123/Imagine/blob/develop/lib/Imagine/Gd/Image.php#L190

What do you think of making it optional and if one isn't given defaulting to the currently loaded image like resize() would.

[romainneutron]

This is not possible for the moment as the ImageInterface does not know anything about the source (may be a binary string, may be a file...).

It could be solved by passing some data about the source itself to the ImageInterface. This introduces a concept of metadata in ImageInterface. Metadata could be an array of metadata parameters that could be used for such operation.

What you (@dmyers and others) think about this ?

[dmyers]

Oh I see what you're saying it just knows the resource, but not the path that is currently loaded. Wonder if some refactoring could bring this feature in? It does seem strange that resize() doesn't require a path doesn't it?

[romainneutron]

This is doable but introduce a new concept. Let's think about this for version 0.6

[dmyers]

Thanks @romainneutron, you rock! 👍