lib/CXGN/Configuration.pm

   1
   2 =head1 NAME
   3
   4 CXGN::Configuration
   5
   6 =head1 DESCRIPTION
   7
   8 Reads in a configuration file in a certain syntax and stores this configuration for access by scripts. Takes item names and lists of values for that item. Puts values as arrayrefs into a hash with the item names as a keys.
   9
  10     #syntax example
  11
  12     #comment
  13     <name1> <value1>
  14
  15     #comment
  16     <name2> <value2>  #another comment
  17
  18     #this example will put multiple values into name3
  19     <name3> <value3.0> <value3.1> <value3.2>
  20
  21 =head1 OBJECT METHODS
  22
  23 =head2 new
  24
  25 Creates a new configuration object.
  26
  27     #example
  28     use CXGN::Configuration;
  29     my $config=CXGN::Configuration->new($config_file_location);
  30
  31 =head2 get_conf
  32
  33 Gives you back the FIRST value for the variable you ask for, using the information that was retrieved from the configuration file. If there are many values for this variable, and you want them, you must use get_conf_arrayref().
  34
  35     #example which gets the locally located location of your web checkout
  36     my $basepath=$config->get_conf('basepath');
  37
  38 =head2 get_conf_arrayref
  39
  40 Gives you back an arrayref of the values for the variable you ask for, even if there is one value or no values.
  41
  42 =head2 get_conf_hashref_single_values
  43
  44 Gives you back a hash with all your items, and the first values in their lists.
  45
  46 =head2 parse_line
  47
  48 For internal use. Gets a variable name from the configuration file and assigns a value or values to it.
  49
  50 =head1 AUTHOR
  51
  52 john binns - John Binns <zombieite@gmail.com>
  53
  54 =cut
  55
  56 package CXGN::Configuration;
  57 use strict;
  58 sub new
  59 {
  60     my $class=shift;
  61     my $self=bless({},$class);
  62     $self->{conf_files}=\@_;
  63     my $FILE;
  64     my $files_found=0;
  65     for my $file_location(@{$self->{conf_files}})#these will be done in order, so later ones will override earlier ones
  66     {
  67         if(-f($file_location))
  68         {
  69             $files_found++;
  70             if(open($FILE,$file_location))
  71             {
  72 #             warn "parsing config $file_location\n";
  73                 while(my $line=<$FILE>)
  74                 {
  75                     chomp($line);
  76                     my($name,$values)=$self->parse_line($line);
  77                     if($name)
  78                     {
  79                         $self->{config}->{$name}=$values;#set this element, and override any previously existing configuration setting for this element
  80                     }
  81                 }
  82             }
  83             else{warn"CXGN::Configuration: Cannot open file '$file_location: $!'.\n";return;}
  84         }
  85         #else{warn"CXGN::Configuration: File '$file_location' does not exist.\n";}
  86     }
  87     unless($files_found){warn"CXGN::Configuration: None of the requested configuration files were found.\n";return;}
  88     return $self;
  89 }
  90 sub parse_line
  91 {
  92     my $self=shift;
  93     my($line)=@_;
  94     $line =~ s/#.+//; #remove any comments from consideration
  95     return unless $line =~ /\S/; #ignore empty lines
  96     my($name,@values)=split(/[\t ]+/,$line);
  97     unless(defined($values[0])){$values[0]='';}#let's make "no value" be stored as an empty string instead
  98     return($name,\@values);
  99 }
 100 sub get_conf#returns a single scalar value even if this item contains more than one value. use get_conf_arrayref to get all values for this item.
 101 {
 102     my $self=shift;
 103     my($requested_conf)=@_;
 104     if($requested_conf and defined($self->{config}->{$requested_conf}))
 105     {
 106         return $self->{config}->{$requested_conf}->[0];
 107     }
 108     else
 109     {
 110         return;
 111     }
 112 }
 113 sub get_conf_arrayref#returns an arrayref, even if a single value is stored
 114 {
 115     my $self=shift;
 116     my($requested_conf)=@_;
 117     return $self->{config}->{$requested_conf};
 118 }
 119 sub get_conf_hashref_single_values#returns a hashref with single values for all items, even if multiple values are available
 120 {
 121     my $self=shift;
 122     my %hash;
 123     for my $key(keys(%{$self->{config}}))
 124     {
 125         $hash{$key}=$self->{config}->{$key}->[0];
 126     }
 127     return \%hash;
 128 }
 129 1;