[richfaces-issues] [JBoss JIRA] (RF-13514) Support file upload progress tracking in Servlets >= 3.0 environment

Support file upload progress tracking in Servlets >= 3.0 environment -------------------------------------------------------------------- Key: RF-13514 URL: https://issues.jboss.org/browse/RF-13514 Project: RichFaces Issue Type: Enhancement Security Level: Public(Everyone can see) Components: component-input, core Affects Versions: 5.0.0.Alpha3 Reporter: Lukáš Fryč Fix For: 5.0.0.Alpha4 We currently support two approaches for file upload: * Servlets 2.5: own request form data parser [{{MultipartRequestParser}}|https://github.com/richfaces/richfaces/blob/master/framework/src/main/java/org/richfaces/request/MultipartRequestParser.java] * Servlets 3.0: leveraging {{HttpServletRequest#getParts()}} However as we have discussed RF-13444, we had to finally do a trade-off of limiting support of file progress tracking. I.e. in Servlets 3.0 we have no simple way how to track file upload progress since getParts() returns data for completed request. There are several possible outcomes: 1) drop server-side file upload progress tracking and leverage XHR2/HTML5 that has built-in ability to track progress * imho we are already prepared to switch to XHR2 and client-side progress (possibly leveraging some third-party widget) since [all major browsers support it at least one version back|http://caniuse.com/#feat=xhr2] * existing implementation: http://www.script-tutorials.com/pure-html5-file-upload/ 2) use a {{ServletFilter}} to wrap a request as our {{FileUploadFacesContextFactory}} currently do and so have an earlier access to the request object * this principle has a drawback - we have to ensure our filter has high-enough priority so the servlet container won't touch the request body yet