The functionality is available within the context of the feature you're using. If it's a Word document you open the document, click the share icon and click "Send Attachment". Apple's Pages also has a Share icon that even lets you easily convert to Word, PDF, or ePub format before sending.
For attaching whilst composing an email in Gmail (what I use) there's an "Attach" icon that lets you attach photos or files from Google Drive. Whilst Apple's Mail lets you click the cursor on where you want to add the Photo/Video.
This works great until it doesn't. Sometimes when you try using the "Share" or "Open In..." buttons, the medium you want to use is not an option. If that's the case, there is no way to manually change it. For example: we have guys who use iPads instead of PCs. When we were first implementing this, we discovered that even though they had Excel for iPad installed, you couldn't open an Excel document attached to an email in Excel. The Open In... dialogue didn't offer Excel as an option. I ended up just using Numbers instead, which brought its own problems (like not fully supporting the .xlsx format).
If the feature was considered important enough to complicate the UI there'd be an option or optimized App for the task, otherwise no-one thought it was important or cared enough to support it.
Right, Apple decided it wasn't important so that means it isn't important?
Being on an e-mail thread where someone says "hey, can you e-mail over that spreadsheet?" is hardly rare. Things like this are the reason why the iPad has not been a huge success as a productivity tool.
> Right, Apple decided it wasn't important so that means it isn't important?
I was referring to all Mail Apps, I don't even use Apple Mail, I use Gmail.
Yes Apple decides what's important in their App, Google decides what's important in theirs, Everyone else decides...
> Being on an e-mail thread where someone says "hey, can you e-mail over that spreadsheet?" is hardly rare.
You can still send spreadsheet attachments, open said Spread sheet, hit share attachment, Done. Go back to playing games.
> iPad has not been a huge success as a productivity tool.
So catering for a smaller class of enterprise and power users should be the holy metric Apple should be catering for?
Apple has OSX for power users, iOS for everyone else. That strategy seems to be working quite well for them.
For attaching whilst composing an email in Gmail (what I use) there's an "Attach" icon that lets you attach photos or files from Google Drive. Whilst Apple's Mail lets you click the cursor on where you want to add the Photo/Video.