Hi,
I've taken a look at the POC, looks pretty good - I have some comments
below.
* I am not sure why you re-implement the casting of the correct table type
instead of using language inheritance; I'm referring to:
table_new = tables_available[table_name]
table_kargs = {'project_id' :request.session['project_id']}
table = table_new(**table_kargs)
...
tables_available = {
'recipes' : RecipeTable,
'layer' : LayersTable,
# ...and so on
}
Instead of just directly sub-classing Table > ToasterTable > RecipeTable;
This approach would ensure proper endpoints directly in the template view
class, instead having to manually sync the *tables_available* with the
defined classes and magic keywords for the table name. Also, see next point.
* I understand the need to have different endpoints for HTML and JSON
returns; I would argue that these are just different views of the same
object - the table object, also see the last point - and in REST fashion ,
they should have related URLs.
I.E instead of using *layers-poc*/ and *table-poc/layers* as HTML/JSON
endpoints, I would use *layers-poc/* and *layers-poc/.json* . This ties
into the inheritance point above, as the Toaster.get() can be written to
return HTML/JSON based on the calling endpoint.
* There is not clear to me how the cache invalidation happens. Considering
that frequently we change the database data through the Bitbake interface,
as opposed to the user interface, we need some sort of policy on cache
invalidation.
* I like the concept of using AJAX to refresh the table content; I am a bit
concerned about lack of graceful degradation, e.g. what the user sees if
there is no JS enabled on the machine. I would suggest rendering the
initial data content (in some way) in HTML and enable minimal
pagination/search/interaction links to run using classic HTML href requests
(this implementation needs to provide minimum navigation, and does not need
be complete); the layer using AJAX to refresh the data should come on top
of the basic functionality - e.g. change the links from HTML href to
javascript actions - as to provide the better experience if JS is enabled;
but we shouldn't penalize our users for not using JS.
I'm not touching minor issues as this is clearly a POC for opening up the
discussion and not a ready-to-drop replacement.
Thank you and keep up the impressive work that went into this !
Cheers,
Alex
On Fri, Mar 27, 2015 at 1:51 PM, Michael Wood <[email protected]>
wrote:
> On 27/03/15 11:44, Barros Pena, Belen wrote:
>
>> Hi Michael,
>>
>> Thanks for this. I have a couple of questions, if that's ok.
>>
>> 1. Can you share some context about what is prompting this refactoring of
>> the front-end code? I know the background because I talk to you all the
>> time, but it might be useful to other people on the list.
>>
>
> Sure,
>
> Currently we have a collection of defined ways to describe a table in
> Toaster on the back end and the front end.
> The first purpose is to consolidate this into a single object on the
> back-end and a single handler on the front end, doing this will hopefully
> mean fewer bugs and consistency in behaviour and look across all the tables.
>
> It also allows us to add features that can then be utilised across all
> tables, such as the one included in this patch which is an improvement to
> the user experience by avoiding having to do a page reload for every table
> operation. I also think it improves the speed of the page loading because
> we're only exposing the fields from the database that we require rather
> than an object that represents all the data and has an easy way to
> implement caching.
>
>
>> 2. Can you provide more details about the "easy switch path"? :) When
>> would be a good time to do it, what kind of extra QA work would be
>> required (if any), etc
>>
> Don't think there would be any extra QA work. If anything it may be
> simpler because we can write some tests that check the JSON output. The
> easy switch path is that it can be done gradually if we want. The best time
> would probably be after 1.8 -- nothing stopping us branching and starting
> now.
>
>
>> 3. Do you think this approach can be expanded to the other UI components
>> (filters, sorting, edit values in forms, layer dependencies modal dialogs,
>> type ahead, etc)? Do you have a full list of what those components would
>> be? How much work / time will it take to create them and making the
>> switch, etc...
>>
> No I don't have a list, (filters will be part of the table work I just
> didn't implement them for the POC) It'd be good to make one, then a better
> time estimate could be made. It took around 4 days to do the table stuff,
> but that included a lot of experimenting and reading around it.
>
> Yes I think we could expand this approach to other components, we have a
> few done already on the client side; typeahead and the layer dependency
> modal mechanism.
> We would need to do an audit and workout what other common components
> could be done.
>
>
>
>> Sorry for all the questions: I am keen on doing this so that we have a
>> solid foundation for the impending feature creep, but I am having some
>> trouble picturing how much time / effort is involved.
>>
>> Thanks!
>>
>> Belén
>>
>> On 26/03/2015 18:21, "Michael Wood" <[email protected]> wrote:
>>
>> Here is the current WIP of the proof of concept of the Tables widget for
>>> toaster
>>>
>>> http://git.yoctoproject.org/cgit/cgit.cgi/poky-contrib/
>>> log/?h=michaelw/toa
>>> ster-tables-poc
>>> ( http://tinyurl.com/op63pgj )
>>>
>>>
>>> I've tried to prefix/postfix 'poc' to make it easier to identify which
>>> are for the proof of concept
>>>
>>> Brief overview of the files/changes:
>>>
>>> ----------------------
>>> poc_view.py:
>>>
>>> Table(View):
>>> - Handles the HTTP requests to get the table data
>>> - Adds some basic caching (future - this can be tied into the
>>> request but for now is just global)
>>>
>>>
>>> ToasterTable(object):
>>> - Adds a base class for common table functionality
>>> - A lot of this is bringing in all the parts we already have in
>>> views.py and standardising them in a single class
>>> - In many tables we have what I've named "static data" this is
>>> where we have a column that contains html data, for example a button.
>>> - Outputs the data for the page requested as a JSON document
>>>
>>>
>>> RecipeTable(ToasterTable):
>>> - Example of a table which has static data
>>>
>>> LayersTable(ToasterTable):
>>> - Example of a simple table
>>>
>>> ----------------------
>>>
>>> tables.js:
>>> - This consumes the table data
>>> - Adds handlers for all the table chrome buttons
>>> - Implements the add/remove columns
>>> - Implements paging
>>>
>>> ----------------------
>>>
>>> table-poc.html:
>>> - Template that just contains the html for the table layout (i.e.
>>> search bar, table, buttons etc)
>>> - can be considered the same as conflating the "basetable_top.html"
>>> + "basetable_bottom.html" templates
>>>
>>> ----------------------
>>>
>>> generic-table-page-poc.html:
>>> - This is a normal table page in toaster with navigation, zone
>>> alert and which includes the table-poc.html template the context
>>> variable table_name is passed into this template to select which table
>>> to display
>>>
>>> ----------------------
>>>
>>> two-tables-poc.html:
>>> - Exactly the same as generic-table-page-poc.html (above) but has
>>> two tables in it.
>>>
>>> ----------------------
>>>
>>> changes to urls.py:
>>> - Add the poc-table this calls into to Table(View) to handle the
>>> requests made from the ajax calls (could be renamed xhr_table for
>>> consistency)
>>> - Add urls for the test pages: /layers-poc/ and /recipes-poc/ and
>>> /two-tables-poc/ note that they don't need their own views defined
>>> because the only thing changing is the table_name and that's passed in.
>>>
>>> ----------------------
>>>
>>> Notes:
>>>
>>> The whole lot is 642 lines which means the maintenance burden shouldn't
>>> be too high
>>> There's a fairly easy path to switching our existing tables - one at a
>>> time if needed
>>> There are bugs and features missing - This is just the proof of concept!
>>>
>>> Thanks,
>>>
>>> Michael
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> --
>>> _______________________________________________
>>> toaster mailing list
>>> [email protected]
>>> https://lists.yoctoproject.org/listinfo/toaster
>>>
>>
> --
> _______________________________________________
> toaster mailing list
> [email protected]
> https://lists.yoctoproject.org/listinfo/toaster
>
--
Alex Damian
Yocto Project
SSG / OTC
--
_______________________________________________
toaster mailing list
[email protected]
https://lists.yoctoproject.org/listinfo/toaster
