Edgewall Software

Version 8 (modified by cboos, 5 years ago) (diff)

stricter Request.write

TracDev/ApiChanges/0.12

Summary

  1. New Dependencies
    1. Babel (optional)
  2. Modifications made to the 0.11 API
    1. Modified Interfaces
      1. IWikiMacroProvider (0.12)​ (0.11)​
      2. IWikiPageManipulator (0.12)​ (0.11)​
    2. Other Changes to the 0.11 API
      1. Href with an empty base (0.12)​ (0.11)​
      2. tracd and HTTP/1.1
  3. New in the 0.12 API
    1. New Classes
      1. trac.cache.CacheProxy (0.12)​
    2. New Interfaces
      1. trac.resource.IResourceManager (0.12)​

New Dependencies

Babel (optional)

The internationalization support (i18) for Trac is depending on Babel.

It's perfectly fine to go on using Trac without it, but then of course the interface will remain in English.

Modifications made to the 0.11 API

Modified Interfaces

IWikiMacroProvider (0.12) (0.11)

Added an optional argument args to IWikiMacroProvider.expand_macro() to contain the shebang-line arguments when using wiki processor syntax. For example, with the following content:

{{{
#!MyMacro test=123 other="This is a text"
This is the content.
}}}

The macro MyMacro will have its expand_macro() called with args={'test': '123', 'other': 'This is a text'}.

See also #8204.

IWikiPageManipulator (0.12) (0.11)

This interface has not actually been changed, but the implementation has been fixed so that it actually does what it promises, that is, validate a wiki page after it's been populated from user input. Previously, page.text would contain the old text, and the new text would typically be retrieved with req.args.get('text') as a workaround.

The page now has the new text in page.text, and the old text in page.old_text.

See also #7731.

Other Changes to the 0.11 API

Href with an empty base (0.12) (0.11)

The Href class has been changed to ensure that it always generates valid URLs, even with an empty base. In 0.11, the following uses all return an empty string:

# 0.11
>>> href = Href('')             # Also applies to Href('/')
>>> href()
''
>>> href('/')
''

In 0.12, the same expressions return a valid relative URL:

# 0.12
>>> href = Href('')
>>> href()
'/'
>>> href('/')
'/'

This change will break plugins that use the following idiom to concatenate the base URL with a path starting with a slash:

# 0.12
>>> href = Href('')
>>> path = '/path/to/page'
>>> href() + path               # Broken
'//path/to/page'

For this specific use case, a new syntax has been added to avoid doubled slashes:

# 0.12 and 0.11.6
>>> href = Href('')
>>> path = '/path/to/page'
>>> href + path                 # New syntax
'/path/to/page'

The new syntax has been backported to 0.11-stable in 0.11.6 to facilitate compatibility of plugins with both 0.11.6 and 0.12. If compatibility with older releases of the 0.11.x branch is required, the following code can be used:

# 0.12 and 0.11.x
>>> href = Href('')
>>> path = '/path/to/page'
>>> href().rstrip('/') + path   # Compatibility
'/path/to/page'

See also #8159.

tracd and HTTP/1.1

Since 0.11.5, tracd could be used with the --http11 flag, which would select the use of the HTTP/1.1 protocol and most notably activate Keep-Alive connections. This is now the default behavior in 0.12.

This has some important consequences for plugins which send content directly to the client. They should take care of setting the Content-Length header properly, otherwise the browser will simply "hang".

This means that any:

    req.write(content)

must be preceded by a:

    req.send_header('Content-Length', len(content))

Don't forget to do that for any data directly sent back to the client, including responses for XHRs (e.g. r8300). This requires a some discipline in the coding, but the benefit is a huge performance boost for tracd, so it's well worth the price.

In order to make errors more immediately visible, the Request.write method is more strict in 0.12: it only accepts str data parameter, and will also raise an exception if the Content-Length header was not set prior to the call.

See #8020 and #8675 for details.

New in the 0.12 API

New Classes

trac.cache.CacheProxy (0.12)

There's a new cache subsystem in trac.cache so that Component instances can cache any data in a safe way. Whenever the cache entry is invalidated, the cached value will be automatically refreshed at the next retrieval, even if the invalidation occurs in a different process. This makes the config.touch() trick obsolete.

New decorators:

See TracDev/Proposals/CacheInvalidation#CacheManager

New Interfaces

trac.resource.IResourceManager (0.12)

FIXME just an example