a new JSON-based configuration file and parser

hive_config.json

+{
+    "Graph" : {
+        "Colours" : {
+            "Status" : {
+                "BLOCKED"     : "grey",
+                "LOADING"     : "yellow",
+                "SYNCHING"    : "yellow",
+                "READY"       : "yellow",
+                "WORKING"     : "yellow",
+                "ALL_CLAIMED" : "yellow",
+                "DONE"        : "green",
+                "FAILED"      : "red",
+                "OTHER"       : "white",
+                "TABLE"       : "black",
+            },
+            "Flows" : {
+                "data"       : "blue",
+                "control"    : "red",
+                "semablock"  : "red",
+            },
+        },
+        "Fonts" : {
+            "node" : "Helvetica",
+            "edge" : "Helvetica",
+        },
+        "DisplayDetails"        : 1,
+        "DisplaySemaphoreBoxes" : 1,
+        "DisplayStretched"      : 0,
+    }
+}
+

modules/Bio/EnsEMBL/Hive/Utils/Config.pm

+#!/usr/bin/env perl
+
+package Bio::EnsEMBL::Hive::Utils::Config;
+
+use JSON;
+
+sub new {
+    my $class = shift @_;
+
+    my $self = bless {}, $class;
+    $self->config_hash( {} );
+
+    foreach my $cfg_file (@_) {
+        if(my $cfg_hash = $self->load_from_json($cfg_file)) {
+            $self->merge($cfg_hash);
+        }
+    }
+
+    return $self;
+}
+
+
+sub config_hash {
+    my $self = shift @_;
+
+    if(@_) {
+        $self->{_config_hash} = shift @_;
+    }
+    return $self->{_config_hash};
+}
+
+
+sub load_from_json {
+    my ($self, $filename) = @_;
+
+    if(-r $filename) {
+        my $json_text   = `cat $filename`;
+        my $json_parser = JSON->new->relaxed;
+        my $perl_hash   = $json_parser->decode($json_text);
+        
+        return $perl_hash;
+    } else {
+        warn "Can't read from '$filename'";
+
+        return undef;
+    }
+}
+
+
+sub merge {
+    my $self = shift @_;
+    my $from = shift @_;
+    my $to   = shift @_ || $self->config_hash;  # only defined in subsequent recursion steps
+
+    while(my ($key,$value) = each %$from) {
+        if(exists $to->{$key} and ref($to->{$key})) {
+            $self->merge($from->{$key}, $to->{$key});
+        } else {
+            $to->{$key} = $from->{$key};
+        }
+    }
+}
+
+
+sub get {
+    my $self        = shift @_;
+    my $option_name = pop @_;
+
+    my $hash_ptr    = $self->config_hash;
+    my $option_value = $hash_ptr->{$option_name};   # not necessatily defined
+
+    foreach my $context_syll (@_) {
+        $hash_ptr = $hash_ptr->{$context_syll};
+        if(exists $hash_ptr->{$option_name}) {
+            $option_value = $hash_ptr->{$option_name};
+        }
+    }
+
+    return $option_value;
+}
+
+1;
+