Re: Storage 'length' and enumeration

[John J. Barton]

Ian Hickson wrote: On Tue, 28 Apr 2009, John J Barton wrote: Sorry, I don't follow what you mean. The loop is possible of course, but what should the result be? If I have a sessionStorage object |s| with 10 items, the length will be 10. Should I expect |s[i]| for i=0,..., 9? If so what will be the result, keys? items? Can I set values, eg s[2] = "howdy"? Keys: # The object's indices of the supported indexed properties are the numbers # in the range zero to one less than the number of key/value pairs # currently present in the list associated with the object. >From the IDL: # [IndexGetter] DOMString key(in unsigned long index); # The key(n) method must return the name of the nth key in the list. >From the perspective of development tools (and perhaps thus developers), this pseudo-array interface is unfortunate. Storage is neither an array of entries nor an associative array. As such, tools like Firebug will just show it as Object with a curious property 'length' which looks like a key but is not. I think a getLength() function would be more true to the character of the type. See WebIDL for the definition of the [IndexGetter] syntax. I could not figure out from the WebIDL what happens in this case:    sessionStore[2] = "howdy"; // no other keys in sessionStore I guess this does not work like _javascript_ arrays or objects, rather I expect it fails? jjb