David E. Wheeler > App-Sqitch-0.972 > App::Sqitch::Plan

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Module Version: 0.972   Source   Latest Release: App-Sqitch-0.992

Name ^

App::Sqitch::Plan - Sqitch Deployment Plan

Synopsis ^

  my $plan = App::Sqitch::Plan->new( sqitch => $sqitch );
  while (my $change = $plan->next) {
      say "Deploy ", $change->format_name;
  }

Description ^

App::Sqitch::Plan provides the interface for a Sqitch plan. It parses a plan file and provides an iteration interface for working with the plan.

Interface ^

Constants

SYNTAX_VERSION

Returns the current version of the Sqitch plan syntax. Used for the %sytax-version pragma.

Class Methods

name_regex

  die "$this has no name" unless $this =~ App::Sqitch::Plan->name_regex;

Returns a regular expression that matches names. Note that it is not anchored, so if you need to make sure that a string is a valid name and nothing else, you will need to anchor it yourself, like so:

    my $name_re = App::Sqitch::Plan->name_regex;
    die "$this is not a valid name" if $this !~ /\A$name_re\z/;

Constructors

new

  my $plan = App::Sqitch::Plan->new( sqitch => $sqitch );

Instantiates and returns a App::Sqitch::Plan object. Takes a single parameter: an App::Sqitch object.

Accessors

sqitch

  my $sqitch = $cmd->sqitch;

Returns the App::Sqitch object that instantiated the plan.

position

Returns the current position of the iterator. This is an integer that's used as an index into plan. If next() has not been called, or if reset() has been called, the value will be -1, meaning it is outside of the plan. When next returns undef, the value will be the last index in the plan plus 1.

project

  my $project = $plan->project;

Returns the name of the project as set via the %project pragma in the plan file.

uri

  my $uri = $plan->uri;

Returns the URI for the project as set via the %uri pragma, which is optional. If it is not present, undef will be returned.

syntax_version

  my $syntax_version = $plan->syntax_version;

Returns the plan syntax version, which is always the latest version.

Instance Methods

index_of

  my $index      = $plan->index_of('6c2f28d125aff1deea615f8de774599acf39a7a1');
  my $foo_index  = $plan->index_of('@foo');
  my $bar_index  = $plan->index_of('bar');
  my $bar1_index = $plan->index_of('bar@alpha')
  my $bar2_index = $plan->index_of('bar@HEAD');

Returns the index of the specified change. Returns undef if no such change exists. The argument may be any one of:

get

  my $change = $plan->get('6c2f28d125aff1deea615f8de774599acf39a7a1');
  my $foo    = $plan->get('@foo');
  my $bar    = $plan->get('bar');
  my $bar1   = $plan->get('bar@alpha')
  my $bar2   = $plan->get('bar@HEAD');

Returns the change corresponding to the specified ID or name. The argument may be in any of the formats described for index_of().

find

  my $change = $plan->find('6c2f28d125aff1deea615f8de774599acf39a7a1');
  my $foo    = $plan->find('@foo');
  my $bar    = $plan->find('bar');
  my $bar1   = $plan->find('bar@alpha')
  my $bar2   = $plan->find('bar@HEAD');

Finds the change corresponding to the specified ID or name. The argument may be in any of the formats described for index_of(). Unlike get(), find() will not throw an error if more than one change exists with the specified name, but will return the first instance.

first_index_of

  my $index = $plan->first_index_of($change_name);
  my $index = $plan->first_index_of($change_name, $change_or_tag_name);

Returns the index of the first instance of the named change in the plan. If a second argument is passed, the index of the first instance of the change after the the index of the second argument will be returned. This is useful for getting the index of a change as it was deployed after a particular tag, for example, to get the first index of the foo change since the @beta tag, do this:

  my $index = $plan->first_index_of('foo', '@beta');

You can also specify the first instance of a change after another change, including such a change at the point of a tag:

  my $index = $plan->first_index_of('foo', 'users_table@beta1');

The second argument must unambiguously refer to a single change in the plan. As such, it should usually be a tag name or tag-qualified change name. Returns undef if the change does not appear in the plan, or if it does not appear after the specified second argument change name.

last_tagged_change

  my $change = $plan->last_tagged_change;

Returns the last tagged change object. Returns undef if no changes have been tagged.

change_at

  my $change = $plan->change_at($index);

Returns the change at the specified index.

seek

  $plan->seek('@foo');
  $plan->seek('bar');

Move the plan position to the specified change. Dies if the change cannot be found in the plan.

reset

   $plan->reset;

Resets iteration. Same as $plan->position(-1), but better.

next

  while (my $change = $plan->next) {
      say "Deploy ", $change->format_name;
  }

Returns the next change in the plan. Returns undef if there are no more changes.

last

  my $change = $plan->last;

Returns the last change in the plan. Does not change the current position.

current

   my $change = $plan->current;

Returns the same change as was last returned by next(). Returns undef if next() has not been called or if the plan has been reset.

peek

   my $change = $plan->peek;

Returns the next change in the plan without incrementing the iterator. Returns undef if there are no more changes beyond the current change.

changes

  my @changes = $plan->changes;

Returns all of the changes in the plan. This constitutes the entire plan.

tags

  my @tags = $plan->tags;

Returns all of the tags in the plan.

count

  my $count = $plan->count;

Returns the number of changes in the plan.

lines

  my @lines = $plan->lines;

Returns all of the lines in the plan. This includes all the changes, tags, pragmas, and blank lines.

do

  $plan->do(sub { say $_[0]->name; return $_[0]; });
  $plan->do(sub { say $_->name;    return $_;    });

Pass a code reference to this method to execute it for each change in the plan. Each change will be stored in $_ before executing the code reference, and will also be passed as the sole argument. If next() has been called prior to the call to do(), then only the remaining changes in the iterator will passed to the code reference. Iteration terminates when the code reference returns false, so be sure to have it return a true value if you want it to iterate over every change.

search_changes

  my $iter = $engine->search_changes( %params );
  while (my $change = $iter->()) {
      say '* $change->{event}ed $change->{change}";
  }

Searches the changes in the plan returns an iterator code reference with the results. If no parameters are provided, a list of all changes will be returned from the iterator in plan order. The supported parameters are:

event

An array of the type of event to search for. Allowed values are "deploy" and "revert".

name

Limit the results to changes with names matching the specified regular expression.

planner

Limit the changes to those added by planners matching the specified regular expression.

limit

Limit the number of changes to the specified number.

offset

Skip the specified number of events.

direction

Return the results in the specified order, which must be a value matching /^(:?a|de)sc/i for "ascending" or "descending".

write_to

  $plan->write_to($file);
  $plan->write_to($file, $from, $to);

Write the plan to the named file, including notes and white space from the original plan file. If from and/or $to are provided, the plan will be written only with the pragmas headers and the lines between those specified changes.

open_script

  my $file_handle = $plan->open_script( $change->deploy_file );

Opens the script file passed to it and returns a file handle for reading. The script file must be encoded in UTF-8.

load

  my $plan_data = $plan->load;

Loads the plan data. Called internally, not meant to be called directly, as it parses the plan file and deploy scripts every time it's called. If you want the all of the changes, call changes() instead. And if you want to load an alternate plan, use parse().

parse

  $plan->parse($plan_data);

Load an alternate plan by passing the complete text of the plan. The text should be UTF-8 encoded. Useful for loading a plan from a different VCS branch, for example.

check_changes

  @changes = $plan->check_changes( $project, @changes );
  @changes = $plan->check_changes( $project, { '@foo' => 1 }, @changes );

Checks a list of changes to validate their dependencies and returns them. If the second argument is a hash reference, its keys should be previously-seen change and tag names that can be assumed to be satisfied requirements for the succeeding changes.

tag

  $plan->tag( name => 'whee' );

Tags a change in the plan. Exits with a fatal error if the tag already exists in the plan or if a change cannot be found to tag. The supported parameters are:

name

The tag name to use. Required.

change

The change to be tagged, specified as a supported change specification as described in sqitchchanges. Defaults to the last change in the plan.

note

A brief note about the tag.

planner_name

The name of the user adding the tag to the plan. Defaults to the value of the user.name configuration variable.

planner_email

The email address of the user adding the tag to the plan. Defaults to the value of the user.email configuration variable.

add

  $plan->add( name => 'whatevs' );
  $plan->add(
      name      => 'widgets',
      requires  => [qw(foo bar)],
      conflicts => [qw(dr_evil)],
  );

Adds a change to the plan. The supported parameters are the same as those passed to the App::Sqitch::Plan::Change constructor. Exits with a fatal error if the change already exists, or if the any of the dependencies are unknown.

rework

  $plan->rework( 'whatevs' );
  $plan->rework( 'widgets', [qw(foo bar)], [qw(dr_evil)] );

Reworks an existing change. Said change must already exist in the plan and be tagged or have a tag following it or an exception will be thrown. The previous occurrence of the change will have the suffix of the most recent tag added to it, and a new tag instance will be added to the list.

Plan File ^

A plan file describes the deployment changes to be run against a database, and is typically maintained using the add and rework commands. Its contents must be plain text encoded as UTF-8. Each line of a plan file may be one of four things:

Here's an example of a plan file with a single deploy change and tag:

 %syntax-version=1.0.0
 +users_table
 @alpha

There may, of course, be any number of tags and changes. Here's an expansion:

 %syntax-version=1.0.0
 +users_table
 +insert_user
 +update_user
 +delete_user
 @root
 @alpha

Here we have four changes -- "users_table", "insert_user", "update_user", and "delete_user" -- followed by two tags: "@root" and "@alpha".

Most plans will have many changes and tags. Here's a longer example with three tagged deployment points, as well as a change that is deployed and later reverted:

 %syntax-version=1.0.0
 +users_table
 +insert_user
 +update_user
 +delete_user
 +dr_evil
 @root
 @alpha

 +widgets_table
 +list_widgets
 @beta

 -dr_evil
 +ftw
 @gamma

Using this plan, to deploy to the "beta" tag, all of the changes up to the "@root" and "@alpha" tags must be deployed, as must changes listed before the "@beta" tag. To then deploy to the "@gamma" tag, the "dr_evil" change must be reverted and the "ftw" change must be deployed. If you then choose to revert to "@alpha", then the "ftw" change will be reverted, the "dr_evil" change re-deployed, and the "@gamma" tag removed; then "list_widgets" must be reverted and the associated "@beta" tag removed, then the "widgets_table" change must be reverted.

Changes can only be repeated if one or more tags intervene. This allows Sqitch to distinguish between them. An example:

 %syntax-version=1.0.0
 +users_table
 @alpha

 +add_widget
 +widgets_table
 @beta

 +add_user
 @gamma

 +widgets_created_at
 @delta

 +add_widget

Note that the "add_widget" change is repeated after the "@beta" tag, and at the end. Sqitch will notice the repetition when it parses this file, and allow it, because at least one tag "@beta" appears between the instances of "add_widget". When deploying, Sqitch will fetch the instance of the deploy script as of the "@delta" tag and apply it as the first change, and then, when it gets to the last change, retrieve the current instance of the deploy script. How does it find such files? The first instances files will either be named add_widget@delta.sql or (soon) findable in the VCS history as of a VCS "delta" tag.

Grammar

Here is the EBNF Grammar for the plan file:

  plan-file    = { <pragma> | <change-line> | <tag-line> | <note-line> | <blank-line> }* ;

  blank-line   = [ <blanks> ] <eol>;
  note-line    = <note> ;
  change-line  = <name> [ "[" { <requires> | <conflicts> } "]" ] ( <eol> | <note> ) ;
  tag-line     = <tag> ( <eol> | <note> ) ;
  pragma       = "%" [ <blanks> ] <name> [ <blanks> ] = [ <blanks> ] <value> ( <eol> | <note> ) ;

  tag          = "@" <name> ;
  requires     = <name> ;
  conflicts    = "!" <name> ;
  name         = <non-punct> [ [ ? non-blank and not "@", ":", or "#" characters ? ] <non-punct> ] ;
  non-punct    = ? non-punctuation, non-blank character ? ;
  value        = ? non-EOL or "#" characters ?

  note         = [ <blanks> ] "#" [ <string> ] <EOL> ;
  eol          = [ <blanks> ] <EOL> ;

  blanks       = ? blank characters ? ;
  string       = ? non-EOL characters ? ;

And written as regular expressions:

  my $eol          = qr/[[:blank:]]*$/
  my $note         = qr/(?:[[:blank:]]+)?[#].+$/;
  my $punct        = q{-!"#$%&'()*+,./:;<=>?@[\\]^`{|}~};
  my $name         = qr/[^$punct[:blank:]](?:(?:[^[:space:]:#@]+)?[^$punct[:blank:]])?/;
  my $tag          = qr/[@]$name/;
  my $requires     = qr/$name/;
  my conflicts     = qr/[!]$name/;
  my $tag_line     = qr/^$tag(?:$note|$eol)/;
  my $change_line  = qr/^$name(?:[[](?:$requires|$conflicts)+[]])?(?:$note|$eol)/;
  my $note_line    = qr/^$note/;
  my $pragma       = qr/^][[:blank:]]*[%][[:blank:]]*$name[[:blank:]]*=[[:blank:]].+?(?:$note|$eol)$/;
  my $blank_line   = qr/^$eol/;
  my $plan         = qr/(?:$pragma|$change_line|$tag_line|$note_line|$blank_line)+/ms;

See Also ^

sqitch

The Sqitch command-line client.

Author ^

David E. Wheeler <david@justatheory.com>

License ^

Copyright (c) 2012-2013 iovation Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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