@aconran what about the other Q?
I hear that Microsoft have finally figured out the suckfulness of their software and are going to allow "all files in X solution folder" to be managed by their new source code control system. I am desperately looking forward to it because I'm currently just periodically zipping my entire solution (which includes all Designer-related stuff) and copying it to a server that's backed up nightly.
P.S., blame is attributable to Visual Studio, too, which refuses to let you search/replace all files in a solution folder that do not technically belong to the solution. So, all my *.js files that weren't added to the solution via the official method, are given a very cold shoulder by the IDE. Very poor form, Microsoft.
it only opens in read mode and i am not able to make changes,how to open in write mode
Things that are automatically generated by Sencha Architect are not editable and you should not touch these directly, instead use the config panel.
Functions (event handlers, configs) and overrides created by you are editable.