Automatically download Symfony YAML component

The attached patch provide for YAML.

Some remarks about adding this patch.

Adding the library to environment.inc has a high DRY (do not repeat yourself) alert.
- I need to add new similar defines
- duplicate and tweak the code from drush_environment_table_lib().
- as this is only the second library this is not a big deal but I guess we need to create an issue for this for future refactoring.

I expected the output of drush vget --format=yaml printing the full $conf array but it only prints the values one by one. This has to do with the implementation of drush_variable_get()

@moshe weitzman you are right about the requirement.

+++ b/includes/output.inc
@@ -393,6 +396,11 @@ function drush_json_decode($var) {
+function drush_yaml_encode($var) {
drush_environment_yaml_lib()
try {
+  $dumper = new sfYamlDumper();
+  return $dumper->dump($var);
}
catch {
  ??
}
+}
+

Invoke drush_environment_yaml_lib() here?

@Rob Loach thanks for the pointer. But not sure what to do with it. In #3 I'm trying to say drush needs some better library management.

I removed the bootstrap download. Only environment.inc and output.inc are now touched.

I tried to make the code a little more generic so we can incorporate a lib quicker the next time.

@moshe weitzman
For drush.entity.inc we print output like this

  drush_print_pipe(drush_format($result));
  drush_print(drush_format($result));

It that wrong? Then we can get rid of the $success. Otherwise the yaml (or other formatter lib) is called twice or more times. Only ConsoleTable is loaded on bootstrap.

A general function is much better but I did not want to clone library module. But yeah let's make it a function.

@Rob Loach
In writing #1396178: Add properties output as a --format I also wanted a hook like structure. So that patch is cool ... but shouldn't that be in another issue? See #1396524: drush vget should spit out one structure so ie vget --json gives one string instead of only values as a side note ;)

Just a note about the location for the libraries.

- I just downloaded 7.x-4.5 (as this is the recommended version)
- Installed it under /usr/local/lib and symlinked /usr/local/bin accordingly
- Next my test user runs drush --version
- drush then tries to download and install Console_Table under /usr/local/lib/drush/includes ... WTF

To make the library install flow workable for ie yaml the location should be ~/.drush/libaries or something similar as yaml support is only installed when needed as @moshe weitzman said in #5

I moved Rob Loach patch to #1441026: Add a hook_drush_output_formats

I'm not sure what we can do with the drush_format_yaml as suggested in #9 as it would require the symphony module to provide for yaml support. It would relieve drush for the library management but ... hmmm.

Attached patch reused the code from #7.

The resulting code is a little clumsy but we need to support non PHP-5.3 installations so cannot use https://github.com/symfony/Yaml as that requires

"require": {
        "php": ">=5.3.3"
    },

Furthermore we support PEAR downloads through drush_lib_fetch().

Removed bad code.
[edit]
< + if (is_dir('lib/YYaml')) {
< + require_once 'lib/Yaml/Dumper.php';
< + require_once 'lib/Yaml/Inline.php';
< + require_once 'lib/Yaml/Escaper.php';
< + }
[/edit]

Nice to know we can rely on PHP 5.3.5

Then it comes down to how do we download the same version as D8 uses from https://github.com/symfony/Yaml or other ways.

http://pear.symfony-project.com/ only supports up to Yaml-1.0.6

So the best option is to follow the instructions from http://symfony.com/doc/current/components/yaml/introduction.html using git fetching a zip.

Patch from #24 fails on D7 while patch from #23 works.

This has to do with class loader stuff. But I like to have the same version of Yaml as D8 has.

In the mean time added a log line for the
+ // This is invoked twice due to normal+piped output generation
just to make sure invocation is fixed.

And made the probing 'debug' level.

(to be continued)

My bad ... it had nothing to do with class loader.

+++ b/commands/core/outputformat/yaml.inc
@@ -5,6 +5,25 @@
+      require_once "$path/Dumper.php";
+      require_once "$path/Inline.php";
+      require_once "$path/Escaper.php";

Needed a DRUSH_BASE_PATH

I have:

- cleaned up the multi call test as mentioned in #25
- removed the is_dir test as tests were done already
- removing the package.xml was PEAR related code
- The $success is not static so also removed from code @ end of drush_environment_yaml_lib()

+++ b/commands/core/outputformat/yaml.inc
@@ -24,9 +40,57 @@ class drush_outputformat_yaml extends drush_outputformat {
+  }
+  require_once $file;
+  return TRUE;
+}

Why do we do this? It make a still missing file inclusion fatal which is good in a way but we try to include this again in line ~19

Good point. But then I prefer the composer route to install the dependencies by hand.

For the debian package the libs need to be included if allowed or added as a deb-dependency.

This way drush provides the plumbing but has no maintenance hassle.

Well let's fix this one then :-)

I start following on #1316322: Add PSR-0 autoloader to drush