i have done application using Extjs, here requirement is need to download file from server also need to showcase loadmask untill file is completely download. Here i am generating dynamic pdf url by appending name to server base URL. some time in server don't have pdf file for particular url(name) may be they will add or delete the pdf files for some names, but i am assigning generated pdf url based on selected name to ifrmae as a source path. if the pdf is not found in server that time iframe is shows a page, like 404 server not found etc... instead of this one i need to showcase alert message pdf file is not available for this particular name. Can anybody tell me How to achieve this one? great appreciated. Thank you.
Here is my code:
Ext.getCmp('pnlPdf').update('<iframe id="iframeId" width="100%" height="85%" frameborder="0" scrolling="no" src="'+speficationUrl+'"></iframe>')