Using Google as a substitute of a web interface for an existing client server application

I am in researh mood and one of the tasks I have in my to do list is:

"Finalize the techonlogy to use for creating a web interface to my existing Client Server application".

My application is very rich and full of features. It makes sense it is has rich client UI, because it is a productivity tool. Many shortcuts, many things without any click. So I am not looking for a full replacement.

My app has some features that would be good to be used also from a web interface.

Some of them:

1) multi user calendar (every item I see in the calendar is linked to something in my app, for example "today 11:00: recall customer 'Dummy ltd'". This is not a simple memo, it is also linked to the customer), so i can see my and others tasks.

2) Confirm some task (yes I did this!)

3) see some report (some graph or some tabular report)

Of course this are not simple outputs, they can contain some logic (for example some calendar items must be readonly, some others can be edited).

This said, I was considering whether doing all this with Google would be a reasonable choice. In this way I don't have to install anything, simply interfacing with google would be enough. I can map my application users to one (or more) google users and use all the google features (calendar, charts, tasks, ....).

May you comment on this? Which are the good/bad points.

Some good points I can forsee:

1) no need to design any UI, just connect to an existing powerful and userfriendly system

2) the applicatino will automatically be compatible with google ("is it possible to export on google?" is a typical question I recieve)

3) google already provides the interface for the points I wrote above (tasks, calendar, charts, ...)

4) no deployment issues. No server hosting. just need to configure the users with some wizard.

Some bad points:

1) Which is the long term support? Will the Google APIs change every month or some of them will be stable for years?

2) How much may I push? How much is it possible to customize? I mean can I write some logic like "this item is readonly", "this item is not"? (afaik in google I can share a calendar with other people, in different ways, but there is no way to make only a part of it readonly. Of course I could do this with a trick, like having 2 calendars, one readonly and the other 开发者_如何学运维not. But is it possible to change the default google behaviour like for example in calendar case?)

3) of course I am limited, writing "from scratch" allows me to do everything.

Final note: my app is a Delphi client/server application. The communication will be done from an application server that will interact with the google apis.

As I understand, the API are stable, for example the Calendar API documentation says

Google periodically updates the Calendar Data API in order to deliver new features and to repair defects discovered in previous versions. In most cases, these changes will be transparent to API developers. However, occasionally we need to make changes that require developers to modify their existing applications.

So as long as the service exists I would expect only small changes. Services however can disappear from one day to the other (see Google Wave for example) so I would check the requirements of an 'exit strategy', at least a way to export the most critical information.

My application is very rich and full of features. It makes sense it is has rich client UI, because it is a productivity tool

It sounds like Morfik might be a good choice for creating web interface for your application. Once you like it, you might even make the whole application in it. ;-)