14948 2011-11-28 15:43:34 +0000 What should getFlowByName return if there is no flow with the given name? 2012-04-11 21:06:40 +0000 1 1 1 Unclassified CSS Regions unspecified PC All RESOLVED FIXED cssom P2 normal --- 1 vhardy vhardy eoconnor mihnea stearns oldest_to_newest 60537 0 vhardy 2011-11-28 15:43:34 +0000 Feedback from Mihnea-Vlad Ovidenie <mihnea@adobe.com> === 1. I have a document that does not have a flow thread. From js, I call document.getFlowByName(".."). I assume that this call returns a null object since I do not yet have a flow thread. 2. Another possibility would be to return a valid js object, that, in the future, if the user adds a flowThread with the desired name, gets connected to the flow thread. Should we support 1 or 2? I would say 1 but the spec does not say anything about the lifetime of the NamedFlow objects. === 65472 1 vhardy 2012-03-13 22:29:01 +0000 So with option 1, we have: // No flow yet var nf = document.getFlowByName('article'); // nf is null // Add content to 'article' nf = document.getFlowByName('article'); // nf is not null // Remove all content from 'article' // nf is now a NamedFlow object that has no content. nf === document.getFlowByName('article'); // evaluates to false.. Since we can have a named flow with no content, I think I would go with option 2: // No flow yet var nf = document.getFlowByName('article'); // nf is not null // Add content to 'article' nf === document.getFlowByName('article'); // evaluates to true // Remove all content from 'article' // nf is now a NamedFlow object that has no content. nf === document.getFlowByName('article'); // evaluates to true.. 65952 2 vhardy 2012-03-22 16:30:58 +0000 (In reply to comment #1) > So with option 1, we have: > > // No flow yet > var nf = document.getFlowByName('article'); // nf is null > > // Add content to 'article' > nf = document.getFlowByName('article'); // nf is not null > > // Remove all content from 'article' > > // nf is now a NamedFlow object that has no content. > nf === document.getFlowByName('article'); // evaluates to false.. > > Since we can have a named flow with no content, I think I would go with option > 2: > > // No flow yet > var nf = document.getFlowByName('article'); // nf is not null > > // Add content to 'article' > nf === document.getFlowByName('article'); // evaluates to true > > // Remove all content from 'article' > > // nf is now a NamedFlow object that has no content. > nf === document.getFlowByName('article'); // evaluates to true.. After discussion: Option 1 with the following precisions: - if a flow has never been referenced by CSS or JS, return null. - if a flow was previous created, but no longer exists, the implementation may return null. - if a script holds on to a reference to a NamedFlow, implementations must guarantee that a) the object is valid (can be used) at all times, and b) subsequent calls to getFlowByName with the same name return the same object. 66128 3 vhardy 2012-03-27 17:06:15 +0000 Changes for this issue: https://dvcs.w3.org/hg/csswg/rev/d4e15f801ff5