disabling a button server-side then re-enabling client-side breaks button postback

Posted on 16th Feb 2014 by admin

I have a tabbed container and a button (not in the container) on a page. If the first tab is selected, I want the button enabled. If the second is selected, I want the button disabled. I have created this functionaliity, but I have encountered some odd behavior. Switching tabs is handled client-side, and therefore, when the tabs are switched, I use something like the following to enable/disable the button client-side based on which tab is selected:view plaincopy to clipboardprint?var saveButton = document.getElementById("<%= btnSave.ClientID %>") if (saveButton) { saveButton.disabled=false; if mytab=="Tab2") { saveButton.disabled=true; } } var saveButton = document.getElementById("<%= btnSave.ClientID %>") if (saveButton) { saveButton.disabled=false; if mytab=="Tab2") { saveButton.disabled=true; } }view plaincopy to clipboardprint? view plaincopy to clipboardprint?This works great but the first problem I run into is, if a control on the second tab (the button is disalbed when this tab is selected) causes a postback, then after the postback the button's state is returned to enabled. This sort of makes sense since the page lifecycle, at this point, knows nothing about what the button state should be. I decided the solution to this would be to check what the current tab is during page load, and if it is the second tab, set the button enabled property to false. In this way, when a postback occurs on the second tab, the button remains disabled. Well, this works to a charm, but I encountered a bizzare side-effect. This works great but the first problem I run into is, if a control on the second tab (the button is disalbed when this tab is selected) causes a postback, then after the postback the button's state is returned to enabled. This sort of makes sense since the page lifecycle, at this point, knows nothing about what the button state should be. I decided the solution to this would be to check what the current tab is during page load, and if it is the second tab, set the button enabled property to false. In this way, when a postback occurs on the second tab, the button remains disabled. Well, this works to a charm, but I encountered a bizzare side-effect.view plaincopy to clipboardprint? view plaincopy to clipboardprint?On the second tab, a postback is caused. The button remains disabled as it should be. I then swith tabs. The client-side code goes into effect and the button client-side disabled property is set to false. However the strange thing is, now the button doesn't work. Clicking on it does not cause a postback and doesn't really do anything. It seems that setting the button enabled property to false and then true server-side, somehow doesn't jive with setting it's disabled property to false on the client. On the second tab, a postback is caused. The button remains disabled as it should be. I then swith tabs. The client-side code goes into effect and the button client-side disabled property is set to false. However the strange thing is, now the button doesn't work. Clicking on it does not cause a postback and doesn't really do anything. It seems that setting the button enabled property to false and then true server-side, somehow doesn't jive with setting it's disabled property to false on the client.view plaincopy to clipboardprint? view plaincopy to clipboardprint?anyone have an idea what is going on?