DataFrames fixes

[Mattriks]

• I've added an entry to NEWS.md
• I've added and/or updated the unit tests
• I've run the regression tests
• I've built the docs and confirmed these changes don't cause new errors

This PR:

• Fixes Tutorial not working (deprecation in dataframes.jl) #1304 (DataFrames deprecated df[:key] syntax)
• Updates dataframes.jl file, testscripts, and docs
• This update might preserve Julia 0.7 compatability

[tlnagy]

This looks great! And thanks for taking the time to update the tests to the new API. I think this'll be an important stopgap change until we update everything to work with the new Tables API (#1292). This is a more thorough update than either #1303 and #1313 so I will merge this one in lieu of those.

[tlnagy]

This update might preserve Julia 0.7 compatability

Did you try running the tests locally on Julia 0.7? I wasn't able to track down the xparse error (https://travis-ci.org/GiovineItalia/Gadfly.jl/jobs/585115113#L505) and master's tests pass for me locally on 0.7 (OpenSUSE Leap 15.1).

[Mattriks]

I need to update the docs too, so don't merge yet.

[tlnagy]

I wasn't going to merge until it passes on 0.7 locally, but yeah, I missed the lack of doc updates. That's needed to truly fix #1304

[Mattriks]

The xparse error is strange and appears to originate in Compose.jl here. There are also new deprecation warnings for Compose with Cairo 0.7, but that's a separate issue too.

[tlnagy]

Yeah, I tried tracking it down to this PR: JuliaIO/JSON.jl#285 (comment) when the switch to the new API was made, but the tests pass so I'm sure why it's failing in Compose's tests.

[codecov-io]

Codecov Report

Merging #1318 into master will decrease coverage by 0.03%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1318      +/-   ##
==========================================
- Coverage    90.1%   90.07%   -0.04%     
==========================================
  Files          36       36              
  Lines        3953     3940      -13     
==========================================
- Hits         3562     3549      -13     
  Misses        391      391

Impacted Files	Coverage Δ
src/dataframes.jl	97.5% <100%> (+6.93%)	⬆️
src/Gadfly.jl	77.58% <0%> (-1.01%)	⬇️

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[Mattriks]

I updated the docs, and they build locally, so this PR is ready to merge.

[Mattriks]

I also tracked down the xparse error. It happens when testing with Julia 0.7, because Parsers.jl 0.2.22 gets installed. xparse is found in Parsers.jl 0.3 (not 0.2.22). So when testing on Julia 0.7, the incorrect version of Parsers.jl is getting installed. Note when testing Gadfly on Julia 1.x, Parsers.jl doesn't appear in the Resolving package version... listing.

[tlnagy]

So when testing on Julia 0.7, the incorrect version of Parsers.jl is getting installed.

I installed Julia 0.7 locally and all the tests passed, it's only on Travis that I saw the xparse error...

I updated the docs, and they build locally, so this PR is ready to merge.

awesome!

[Mattriks]

Parsers 0.2.22 doesn't have an xparse function, so does that mean the Gadfly tests will pass locally on Julia 0.7 if certain lines in Compose are not being evaluated (depending on things like system font setup?)

[tlnagy]

Ah, that makes sense.

PR is ready to merge.

Lets do it.

[Mattriks]

@tlnagy The dev docs haven't built.

[tlnagy]

That's due to the 0.7 builds failing (https://travis-ci.org/GiovineItalia/Gadfly.jl/jobs/589150627) and the doc build getting cancelled. I manually started the doc build, but that's not sustainable going forward.

We need to figure the xparse error on 0.7 or stop testing on Travis on 0.7.

[Mattriks]

Re the first option: Parsers.jl 0.3 (which has xparse) is compatible with Julia 0.7, so what's holding it back at Parsers 0.2.22?

[tlnagy]

Not sure, what's holding it back. Might be one of our dependencies

[Mattriks]

In the Resolving package versions... are there packages that are being added purely to setup the test (by Travis or by Julia Pkg)?, i.e. are some of the listed packages not in any way dependencies of Gadfly?

[tlnagy]

These are the only packages that are installed for tests in addition to the ones Gadfly directly depends on.

Gadfly.jl/Project.toml

Lines 58 to 68 in aa4855c

	[extras]
	CSV = "336ed68f-0bac-5ca0-87d4-7b16caf5d00b"
	Cairo = "159f3aea-2a34-519c-b102-8c37f9878175"
	DataFrames = "a93c6f00-e57d-5684-b7b6-d8193f3e46c0"
	LibGit2 = "76f85450-5226-5b5a-8eaa-529ad045b433"
	RDatasets = "ce6b1742-4840-55fa-b093-852dadbb1d8b"
	Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
	Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"
	[targets]
	test = ["CSV", "Cairo", "DataFrames", "LibGit2", "RDatasets", "Test", "Unitful"]

[tlnagy]

It looks like maybe this is caused by JuliaStats/RDatasets.jl#70 that dropped support for julia 0.7 and is maybe forcing the older version of CSV that requires the old Parsers?

I'm sure how to read the bounds exactly here: https://github.com/JuliaRegistries/General/blob/e69a570be9c66cbdd39c2d94e4e83e897f9000aa/R/RDatasets/Compat.toml#L52-L56

[Mattriks]

Compat.toml bounds: JuliaLang/Pkg.jl#1190 (comment)