Let me clarify that when I suggest a mechanism for execution phase I am really asking for a loader hook that could allow user code to enable such a thing. Not asking that it be built into the loader spec.
- Matthew Robb On Fri, Aug 15, 2014 at 9:56 AM, Matthew Robb <[email protected]> wrote: > In YUI's Loader config you can set up hooks that specify another module > that "triggers" this module. It's the reverse of a dependency. You may want > to say that ModuleX should always be loaded before ModuleA-ModuleD. You > might even want to create this dependency based on environment conditions. > The common case here is polyfills but I have used it for other things as > well. > > I am curious what the reasoning is to not provide a mechanism in the > loader to allow the dependency graph to be adjusted in some manner? It > seems reasonable to me that you should be able to add dependencies to a > module at any time. These are not imported dependencies just load and > potentially execution dependencies and it WOULD be great if this mechanism > provided a model for specifying execution phase. Again similar to YUI's > "before", "after", and "instead" values for the "when" property of its > condition blocks in loader configuration. > > > - Matthew Robb > > > On Fri, Aug 15, 2014 at 9:27 AM, Kevin Smith <[email protected]> wrote: > >> >>> > The structure of the graph has an effect on order-of-execution, though, >>> > so adding edges can result in observable changes. >>> >>> Can you elaborate on this, just so I'm sure I understand it right? >>> >>> >> The execution order is determined by a depth-first traversal of the >> dependency graph starting with the node being loaded, where edges are >> ordered. So adding edges can have an effect on the traversal ordering. >> Execution order is in general not fixed, though, since the user can >> initiate loads of different parts of the graph at arbitrary times. Just >> something to consider. >> >> >>> > 2) The ability to prefetch resources, given a URL which is currently >>> > loading. >>> >> >> As Juan pointed out (and I forgot) this can be done with >> Loader.prototype.load. >> >> >>> > >>> > For example, the user might want to specify up-front a portion of the >>> > dependency graph so that resources in that graph can be downloaded in >>> > parallel. >>> >>> Isn't that just something you can do one you have (1)? I'm not sure I'm >>> following the distinction. >>> >> >> I think there's an important distinction here. Let's say that you have >> this dependency chain: >> >> A -> B -> C >> >> So A depends on both B and C. >> >> Let's say that the user has declaratively indicated that A also depends >> on some other resource D, but A doesn't *actually* depend on D. How should >> things be modeled in that case? Would it make sense to add an edge from A >> to D? >> >> If D is an "actual" dependency, then you would want to execute/initialize >> it before A. On the other hand, if it's just a "likely" dependency, then >> you might want to load it (and it's dependencies) without initializing it, >> using `Loader.prototype.load`, or perhaps some other mechanism. >> >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> >> >
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