RFR : 8213354 : Support package-specific stylesheets

[Jonathan Gibbons]

It's looking good but could still be improved.

1. You haven't followed the typical coding patter for managing a cache 
-- in this case the cache of stylesheets.

The pattern is typically:

     Foo foo = fooCache.get(key);
     if (foo == null) {
         foo = // compute foo
         fooCache.put(key, foo);
    }
     // use foo

In your case, you have most of that pattern in HtmlDocletWriter, but the 
call to update the cache is buried inside DocFilesHandlerImpl.

2. I still don't really like the reference to stylesheets in 
DocFilesHandler, but I can live with it, but you should follow the style 
of the other method and declare that you throw DocletException instead 
of the more specific DocFileIOException. That saves needing the more 
specific import, and allows any future subtypes or upgrades to use other 
subtypes of DocletException if desired. Note that you can change the 
exception here without changing the throws on the implementation method.

3. You are very close to supporting module-specifc stylesheets as well 
as package-specific ones. I'm not suggesting you go all the way for 
this, unless you want to, but I think you should at least generalize the 
cache in HtmlConfiguration to be a Map<Element,List<DocPath>> and 
change/generalize some of the method names as well (e.g. by removing the 
Package word), so that they can be reused if we choose to support 
module-specific stylesheets.

It would be pretty easy to have what is currently 
getPackageLocalStylesheetContent(PackageElement) automatically check if 
the package has an enclosing module and look up the style sheets for the 
enclosing module as well as the package.

-- Jon

On 02/12/2019 12:40 AM, Priya Lakshmi Muthuswamy wrote:
> Hi Jon,
>
> Thanks for the review.
>
> I have modified the DocFilesHandlerImpl to get all the .css files, so 
> that user is not restricted to one name.
> Also included the Map in HtmlConfiguration.
>
> updated webrev : 
> http://cr.openjdk.java.net/~pmuthuswamy/8213354/webrev.01/
>
> Thanks,
> Priya
>
> On 2/9/2019 6:24 AM, Jonathan Gibbons wrote:
>> Hi Priya,
>>
>> There are two significant issues that need to be addressed.
>>
>> 1.
>>
>> In DocFilesHandlerImpl you randomly take the first .css file you find 
>> when listing the directory. If there should only be one, we should 
>> specify the name (e.g. stylesheet.css). Otherwise, I think you should 
>> honor all files found. Note that the order of iteration of a 
>> directory is undefined, and may depend on the operating system, and 
>> may vary over time. That is a very strong reason not to just take the 
>> first file found when listing the directory.
>>
>> In terms of naming, "check..." is not a good name for this method. 
>> I'd suggest either getStylesheet (if you only want to handle one) or 
>> getStyleSheets() returning a List<DocPath> if you support more than 
>> one.  Note that using a list allows you to easily handle no files 
>> found (i.e. an empty list) as well as 1 or more files found.
>>
>> Minor nit: please ensure a space between a keyword and an open 
>> parenthesis. You should be able to configure your IDE for that style; 
>> it is the standard style for JDK code.
>>
>> 2.
>>
>> You should not be modifying anything for this feature in the 
>> jdk/javadoc/internal/doclets/toolkit/ directory. The use of 
>> stylesheets and CSS is specific to the HTML format, and any changes 
>> should be limited to the directory 
>> jdk/javadoc/internal/doclets/formats/html/ (and any subdirectories.)
>>
>> I realize you need to get information into the individual *WriterImpl 
>> classes.  In general, the way we do that is to build and use a table 
>> in the HtmlConfiguration object. Some class like HtmlDoclet can stash 
>> information in that table; other Html classes can access it.  The 
>> table can either be a Map<PackageElement,DocPath> or a 
>> Map<PackageElement,List<DocPath>> depending on whether you support at 
>> most one stylesheet per package or many.
>>
>> If you keep a Map in HtmlConfiguration, you could also compute 
>> entries lazily, and not bother with editing HtmlDoclet. For example, 
>> no entry in the cache means it has not been computed yet, an empty 
>> list in the cache means no package-specific stylesheets, a non-empty 
>> list means you have local stylesheets. This computation can all be 
>> done in DocFilesHandlerImpl, with just the cache object itself being 
>> retained in HtmlConfiguration.
>>
>> -- Jon
>>
>>
>> On 01/30/2019 04:18 AM, Priya Lakshmi Muthuswamy wrote:
>>> Hi,
>>>
>>> Kindly review the fix for 
>>> https://bugs.openjdk.java.net/browse/JDK-8213354
>>> Package specific stylesheets needs to placed under doc-files 
>>> directory of a package.
>>> DocFilesHandler looks for any css file and adds them to the 
>>> generated html pages.
>>>
>>> webrev : http://cr.openjdk.java.net/~pmuthuswamy/8213354/webrev.00/
>>>
>>> Thanks,
>>> Priya
>>>
>>