add propertychange handlder ,and structure change

[guirong]

here is some changes

1. I added a propertychange listener to handle the placeholder attribute change ,so when the attribute change , we can change the input value imidately
2. the updateplaceholder function and the createplaceholder function are almost same, and updatePlaceholder doesn't process the form submit for new added input element, so I merge the two function to one
3. sometimes, I don't wan't use the refresh to process the new input element which added after page loaded,I want a function just attach the new input . so I add "attach" method

in addition， I don't think refresh method has meaning any more, except in the browser don't support properychange event. could you think about it?

[jamesallardice]

By the sound of it, you've basically done what I've been meaning to do for a while now! I'll have a proper look through your changes as soon as I get a chance and hopefully we can merge it in. Thanks.

[jamesallardice]

The updatePlaceholders method no longer exists, so this throws an error.

[ahutchings]

Just ran into this issue - "updatePlaceholder doesn't process the form submit for new added input element", so +1 for this.

[jamesallardice]

@ahutchings I've pushed up a fix for that issue. I'm reluctant to merge in this full pull request due to the fact it contains at least one obvious error. I've been waiting for the opener to get back to me before I'll consider merging. But if you grab the latest version, the new form issue should be solved.

[ahutchings]

Thanks, your fix is working great!

[jamesallardice]

@guirong Please let me know if you are able to go through your pull request and sort out any errors. It's been over a month now so if I don't hear back from you soon I'm going to close this. When I get a chance I may use bits of your code to simplify the library but I'm reluctant to merge this in with obvious errors.

[guirong]

@jamesallardice sorry for that, I will fix it as soon as possible！

[guirong]

replace "updatePlaceholders" by "createPlaceholders", as the original "updatePlaceholders" method's function has been replaced by createPlaceholders.

[guirong]

@jamesallardice What's going on？