The first of the included tests did not pass without the changes to
Observable. The problem occurred when a function read a reactive value
and then wrote it. Any dependents on the function would not receive
any invalidations, then or ever after.
The first problem was that the dirty state was unilaterally set to FALSE
after the function finished executing, which might not be accurate if
the function's newly created was invalidated during its own execution.
Instead we set dirty state to FALSE before executing. But to prevent
reentrant calls from thinking the cached value can be used, we add
a .running field that is also consulted during getValue.
The second problem was that Observable$getValue didn't register the
dependent until after updateValue. That is a problem if updateValue
creates *and* invalidates a context before returning. So now we
register the dependent before calling updateValue.
R CMD check didn't like Cairo::CairoPNG. With this method, check wants
Cairo to be imported in NAMESPACE, but it shouldn't be - Cairo should
be optional.
The `content` function now takes a file path, not writable connection, as an argument.
This makes it much easier to work with APIs that only write to file paths, not
connections.
Some of our examples omit library(shiny) from the top of ui.R and server.R,
which worked fine before but not with the namespace fix from yesterday.
Requiring shiny at startup fixes the problem.
See in particular:
http://stackoverflow.com/questions/13575353/how-does-the-shiny-r-package-deal-with-data-frames
Also reported at different times by Dirk Eddelbuettel and Jay Emerson.
The observed behavior is that S3/S4 method dispatch does not always seem to
work; the desired methods are not invoked despite appearing to be in the
search path.
The problem was that sourcing files with local=TRUE creates a new environment
based on the parent frame, which in our case is Shiny's package environment.
What we really want is to read from the global environment but write to a
throwaway environment. The correct way to do that is to make a new environment
with .GlobalEnv as the parent.
