How to create dynamically sized HTML table? - html

I have a Perl CGI script. I would like to make a dynamic, appropriately-sized table based on query information from a simple HTML form: http://jsfiddle.net/wBgBZ/4/. I wanted to use HTML::Table but the server doesn't have the module installed. The administrator won't install it either. Therefore, I have to do it the old fashion way.
Here's what I have so far.
#!/usr/bin/perl
use strict; use warnings;
use CGI qw( :standard);
print header;
print start_html(
-title => 'Creating Tables'
);
# Process an HTTP request
my $query = param("names");
my #students_in_class = split(/;/, $query);
my %attributes = (
'Tommy' => 'A star baseball player who has lots of potential to play in the Major League of Baseball. ',
'Tyrone' => 'An honor roll athlete. His father is really proud of him. When he graduates, he wents to work at the National Institute for Public Health. His father wants him to become a doctor but he wants to pursue Physics.',
'Marshall' => 'A professional WWE wrestler.',
);
print table({-border=> undef},
caption('Students in the class'),
Tr({-align=>'CENTER',-valign=>'TOP'},
[
th(['Student', 'List of Attributes']),
foreach (#students_in_class){ # !!!!! problem line !!!!!!
td(['$_' , '$attributes{$}']),
}
]
)
);
Such that if the user enters the following into the search bar: Tyrone;Tommy;Marshall
the CGI should produces something similar to the following
Desired Output
http://jsfiddle.net/PrLvU/
If the user enters just Marshall;Tommy, the table should be 3x2.
It doesn't work. I need a way to dynamically add rows to the table.

This is untested, but I think this is what you are wanting. You may need to change some of the table attributes to your desired needs.
use strict;
use warnings;
use CGI qw( :standard );
print header,
start_html(-title => 'Creating Tables');
my $query = param('names');
my #headers;
my #students = split(/;/, $query);
my %attributes = (
Tommy => 'A star baseball player.',
Tyrone => 'An honor roll athlete.',
Marshall => 'A professional WWE wrestler.',
);
$headers[0] = Tr(th('Student'), th('List of Attributes'));
for my $i (#students) {
push #headers, Tr( td($i), td($attributes{$i}));
}
print table( {-border => undef}, #headers );

Related

decode_json and return first key in hash

JSON string input: https://www.alphavantage.co/query?function=TIME_SERIES_DAILY&symbol=MSFT&apikey=demo
I am trying to return just the first key (current day) in the hash but have been unable to do so. My code looks like the following
#!/usr/bin/perl
use strict;
use warnings;
use LWP::Simple;
use Data::Dumper;
use JSON;
my $html = get("https://www.alphavantage.co/query?function=TIME_SERIES_DAILY&symbol=AMD&apikey=CMDPTEHVYH7W5VSZ");
my $decoded = decode_json($html);
my ($open) = $decoded->{'Time Series (Daily)'}->[0]->{'1. open'};
I keep getting "Not an ARRAY reference" which I researched and got more confused.
I can access what I want directly with the below code but I want to access just the first result or the current day:
my ($open) = $decoded->{'Time Series (Daily)'}{'2017-12-20'}{'1. open'};
Also if I do something like this:
my ($open) = $decoded->{'Time Series (Daily)'};
print Dumper($open);
The output is as follows:
$VAR1 = {
'2017-09-07' => {
'1. open' => '12.8400',
'5. volume' => '35467788',
'2. high' => '12.9400',
'4. close' => '12.6300',
'3. low' => '12.6000'
},
'2017-11-15' => {
'3. low' => '10.7700',
'4. close' => '11.0700',
'2. high' => '11.1300',
'5. volume' => '33326871',
'1. open' => '11.0100'
},
'2017-11-30' => {
'1. open' => '10.8700',
'2. high' => '11.0300',
'5. volume' => '43101899',
'3. low' => '10.7600',
'4. close' => '10.8900'
},
Thank you in advance for any help you can provide a noob.
Problem 1: { denotes the start of a JSON object, which gets decoded into a hash. Trying to derefence an array is going to fail.
Problem 2: Like Perl hashes, JSON objects are unordered, so talking about the
"first key" makes no sense. Perhaps you want the most recent date?
use List::Util qw( maxstr );
my $time_series_daily = $decoded->{'Time Series (Daily)'};
my $latest_date = maxstr #$time_series_daily;
my $open = $time_series_daily->{$latest_date}{'1. open'};
You are picking among hashref keys, not array (sequential container) elements. Since hashes are inherently unordered you can't index into that list but need to sort keys as needed.
With the exact format you show this works
my $top = (sort { $b cmp $a } keys %{ $decoded->{'Time Series (Daily)'} } )[0];
say $decoded->{'Time Series (Daily)'}{$top}{'1. open'};
It gets the list of keys, inverse-sorts them (alphabetically), and takes the first element of that list.
If your date-time format may vary then you'll need to parse it for sorting.
If you will really ever only want the most-recent one this is inefficient since it sorts the whole list. Then use a more specific tool to extract only the "largest" element, like
use List::Util qw(reduce);
my $top = reduce { $a gt $b ? $a : $b }
keys %{ $decoded->{'Time Series (Daily)'} };
But then in your case this can be done simply by maxstr from the same List::Util module, as shown in ikegami's answer. On the other hand, if the datetime format doesn't lend itself to a direct lexicographical comparison used by strmax then the reduce allows use of custom comparisons.

HTML Parsing using HTML::Tree in Perl

I'm trying to scrape a webpage and get the values that are inside the html tags. The end result would be a way to separate values in a way that looks like
Club: x Location: y URL: z
Here's what I have so far
use HTML::Tree;
use LWP::Simple;
$url = "http://home.gotsoccer.com/clubs.aspx?&clubname=&clubstate=AL&clubcity=";
$content = get($url);
$tree = HTML::Tree->new();
$tree->parse($content);
#td = $tree->look_down( _tag => 'td', class => 'ClubRow');
foreach $1 (#td) {
print $1->as_text();
print "\n";
}
And what is printed is like
AYSO UnitedMadison, ALwww.aysounitednorthalabama.org
This is what the HTML looks like
<td class="ClubRow" width="80%">
<div>
AYSO United</div>
<div class="SubHeading">Madison, AL</div>
<img src="/images/icons/ArrowRightSm.png" class="LinkIcon"><font color="black">www.aysounitednorthalabama.org</font>
</td>
I need a way to either split these fields into separate variables or add some sort of deliminating character so I can do it with Regex. There isn't much documentation online so any help would be appreciative.
First, this is an abomination:
foreach $1 (#td) {
print $1->as_text();
print "\n";
}
You might think it is cute, but it is confusing to use regex capture variables such as $1 as a loop variable especially since you also say "I need a way... so I can do it with Regex." (emphasis mine)
This is the kind of nonsense that leads to unmaintainable programs which give Perl a bad name.
Always use strict and warnings and use a plain variable for your loops.
Second, you are interested in three specific elements in each td: 1) The text of a[class="ClubLink"]; 2) The text of div[class="SubHeading"]; and 3) The text of font[color="black"].
So, just extract those three bits of information instead of flattening the text inside a td:
#!/usr/bin/env perl
use strict;
use warnings;
use HTML::Tree;
my $html = <<HTML;
<td class="ClubRow" width="80%"> <div> AYSO United</div>
<div class="SubHeading">Madison, AL</div> <a
href="http://www.aysounitednorthalabama.org" target="_blank"><img
src="/images/icons/ArrowRightSm.png" class="LinkIcon"><font
color="black">www.aysounitednorthalabama.org</font></a> </td>
HTML
my $tree = HTML::Tree->new_from_content( $html );
my #wanted = (
[class => 'ClubLink'],
[class => 'SubHeading'],
[_tag => 'font', color => 'black'],
);
my #td = $tree->look_down( _tag => 'td', class => 'ClubRow');
for my $td ( #td ) {
my ($club, $loc, $www) = map $td->look_down(#$_)->as_text, #wanted;
print join(' - ', $club, $loc, $www), "\n";
}
Output:
$ ./gg.pl
AYSO United - Madison, AL - www.aysounitednorthalabama.org
Of course, I would have probably used HTML::TreeBuilder::XPath to take advantage of XPath queries.
Here's a Mojolicious example. It's the same thing that Sinan did but with a different toolbox which has the tools to fetch and process the webpage. It looks a bit long, but that's just the comments and documentation. ;)
I like that Mojolicious is "batteries included", so once I load one of the modules, I probably have everything else I need for the task:
use v5.10;
use Mojo::UserAgent;
my $url = "http://home.gotsoccer.com/clubs.aspx?&clubname=&clubstate=AL&clubcity=";
my $ua = Mojo::UserAgent->new;
my $tx = $ua->get( $url );
# You could do some error checking here in case the fetch fails
$tx->res->dom
# there are lots of ClubRow td cells, but we want the one with
# the width attribute. Find all of those. See Mojo::DOM::CSS for
# docs on CSS selectors.
->find( 'td[class=ClubRow][width=80%]' )
# now go through each td and extract several things
->map( sub {
# these selectors represent the club location, name, and website
state $find = [ qw(
a[class=ClubLink]
div[class=SubHeading]
font[color=black]
) ];
my $chunk = $_;
# return the location, name, and link as a tuple for later
# processing
[
map { s/\t+/ /gr } # remove tabs so we can use them as a separator
map { $chunk->find( $_ )->map( 'text' )->[0] }
#$find
]
} )
# do something will all tuples. In this case, output them as tab
# separated values (which is why you removed tabs already). You
# should be able to easily import this into a spreadsheet application.
->each( sub { say join "\t", #$_ } );
The output has that annoying first line, but you can fix that up on your own:
*****Other Club*****
Alabama Soccer Association www.alsoccer.org
Alabaster Competitive SC acsc.teampages.com/
Alabaster Parks and Rec
Alex City YSL www.alexcitysoccer.com/
Auburn Thunder SC auburnthundersoccer.com/
AYSO United Madison, AL www.aysounitednorthalabama.org
Birmingham Area Adult Soccer League
Birmingham Bundesliga LLC Birmingham, AL www.birmingham7v7.com
Birmingham Premier League
Birmingham United SA Birmingham, AL, AL www.birminghamunited.com/
Blount County Youth Soccer Oneonta, AL bcysfury.com
Briarwood SC Birmingham, AL www.questrecreation.org/briarwood-soccer-club.html...
Capital City Streaks Montgomery, AL www.capitalcitystreaks.org
City of Calera Youth Soccer

Parse any number of subkeys in a perl hash

I have a perl hash that is obtained from parsing JSON. The JSON could be anything a user defined API could generated. The goal is to obtain a date/time string and determine if that date/time is out of bounds according to a user defined threshold. The only issue I have is that perl seems a bit cumbersome when dealing with hash key/subkey iteration. How can I look through all the keys and determine if a key or subkey exists throughout the hash? I have read many threads throughout stackoverflow, but nothing that exactly meets my needs. I only started perl last week so I may be missing something... Let me know if that's the case.
Below is the "relevant" code/subs. For all code see: https://gitlab.com/Jedimaster0/check_http_freshness
use warnings;
use strict;
use LWP::UserAgent;
use Getopt::Std;
use JSON::Parse 'parse_json';
use JSON::Parse 'assert_valid_json';
use DateTime;
use DateTime::Format::Strptime;
# Verify the content-type of the response is JSON
eval {
assert_valid_json ($response->content);
};
if ( $# ){
print "[ERROR] Response isn't valid JSON. Please verify source data. \n$#";
exit EXIT_UNKNOWN;
} else {
# Convert the JSON data into a perl hashrefs
$jsonDecoded = parse_json($response->content);
if ($verbose){print "[SUCCESS] JSON FOUND -> ", $response->content , "\n";}
if (defined $jsonDecoded->{$opts{K}}){
if ($verbose){print "[SUCCESS] JSON KEY FOUND -> ", $opts{K}, ": ", $jsonDecoded->{$opts{K}}, "\n";}
NAGIOS_STATUS(DATETIME_DIFFERENCE(DATETIME_LOOKUP($opts{F}, $jsonDecoded->{$opts{K}})));
} else {
print "[ERROR] Retreived JSON does not contain any data for the specified key: $opts{K}\n";
exit EXIT_UNKNOWN;
}
}
sub DATETIME_LOOKUP {
my $dateFormat = $_[0];
my $dateFromJSON = $_[1];
my $strp = DateTime::Format::Strptime->new(
pattern => $dateFormat,
time_zone => $opts{z},
on_error => sub { print "[ERROR] INVALID TIME FORMAT: $dateFormat OR TIME ZONE: $opts{z} \n$_[1] \n" ; HELP_MESSAGE(); exit EXIT_UNKNOWN; },
);
my $dt = $strp->parse_datetime($dateFromJSON);
if (defined $dt){
if ($verbose){print "[SUCCESS] Time formatted using -> $dateFormat\n", "[SUCCESS] JSON date converted -> $dt $opts{z}\n";}
return $dt;
} else {
print "[ERROR] DATE VARIABLE IS NOT DEFINED. Pattern or timezone incorrect."; exit EXIT_UNKNOWN
}
}
# Subtract JSON date/time from now and return delta
sub DATETIME_DIFFERENCE {
my $dateInitial = $_[0];
my $deltaDate;
# Convert to UTC for standardization of computations and it's just easier to read when everything matches.
$dateInitial->set_time_zone('UTC');
$deltaDate = $dateNowUTC->delta_ms($dateInitial);
if ($verbose){print "[SUCCESS] (NOW) $dateNowUTC UTC - (JSON DATE) $dateInitial ", $dateInitial->time_zone->short_name_for_datetime($dateInitial), " = ", $deltaDate->in_units($opts{u}), " $opts{u} \n";}
return $deltaDate->in_units($opts{u});
}
Sample Data
{
"localDate":"Wednesday 23rd November 2016 11:03:37 PM",
"utcDate":"Wednesday 23rd November 2016 11:03:37 PM",
"format":"l jS F Y h:i:s A",
"returnType":"json",
"timestamp":1479942217,
"timezone":"UTC",
"daylightSavingTime":false,
"url":"http:\/\/www.convert-unix-time.com?t=1479942217",
"subkey":{
"altTimestamp":1479942217,
"altSubkey":{
"thirdTimestamp":1479942217
}
}
}
[SOLVED]
I have used the answer that #HåkonHægland provided. Here are the below code changes. Using the flatten module, I can use any input string that matches the JSON keys. I still have some work to do, but you can see the issue is resolved. Thanks #HåkonHægland.
use warnings;
use strict;
use Data::Dumper;
use LWP::UserAgent;
use Getopt::Std;
use JSON::Parse 'parse_json';
use JSON::Parse 'assert_valid_json';
use Hash::Flatten qw(:all);
use DateTime;
use DateTime::Format::Strptime;
# Verify the content-type of the response is JSON
eval {
assert_valid_json ($response->content);
};
if ( $# ){
print "[ERROR] Response isn't valid JSON. Please verify source data. \n$#";
exit EXIT_UNKNOWN;
} else {
# Convert the JSON data into a perl hashrefs
my $jsonDecoded = parse_json($response->content);
my $flatHash = flatten($jsonDecoded);
if ($verbose){print "[SUCCESS] JSON FOUND -> ", Dumper($flatHash), "\n";}
if (defined $flatHash->{$opts{K}}){
if ($verbose){print "[SUCCESS] JSON KEY FOUND -> ", $opts{K}, ": ", $flatHash>{$opts{K}}, "\n";}
NAGIOS_STATUS(DATETIME_DIFFERENCE(DATETIME_LOOKUP($opts{F}, $flatHash->{$opts{K}})));
} else {
print "[ERROR] Retreived JSON does not contain any data for the specified key: $opts{K}\n";
exit EXIT_UNKNOWN;
}
}
Example:
./check_http_freshness.pl -U http://bastion.mimir-tech.org/json.html -K result.creation_date -v
[SUCCESS] JSON FOUND -> $VAR1 = {
'timestamp' => '20161122T200649',
'result.data_version' => 'data_20161122T200649_data_news_topics',
'result.source_version' => 'kg_release_20160509_r33',
'result.seed_version' => 'seed_20161016',
'success' => 1,
'result.creation_date' => '20161122T200649',
'result.data_id' => 'data_news_topics',
'result.data_tgz_name' => 'data_news_topics_20161122T200649.tgz',
'result.source_data_version' => 'seed_vtv: data_20161016T102932_seed_vtv',
'result.data_digest' => '6b5bf1c2202d6f3983d62c275f689d51'
};
Odd number of elements in anonymous hash at ./check_http_freshness.pl line 78, <DATA> line 1.
[SUCCESS] JSON KEY FOUND -> result.creation_date:
[SUCCESS] Time formatted using -> %Y%m%dT%H%M%S
[SUCCESS] JSON date converted -> 2016-11-22T20:06:49 UTC
[SUCCESS] (NOW) 2016-11-26T19:02:15 UTC - (JSON DATE) 2016-11-22T20:06:49 UTC = 94 hours
[CRITICAL] Delta hours (94) is >= (24) hours. Data is stale.
You could try use Hash::Flatten. For example:
use Hash::Flatten qw(flatten);
my $json_decoded = parse_json($json_str);
my $flat = flatten( $json_decoded );
say "found" if grep /(?:^|\.)\Q$key\E(?:\.?|$)/, keys %$flat;
You can use Data::Visitor::Callback to traverse the data structure. It lets you define callbacks for different kinds of data types inside your structure. Since we're only looking at a hash it's relatively simple.
The following program has a predefined list of keys to find (those would be user input in your case). I converted your example JSON to a Perl hashref and included it in the code because the conversion is not relevant. The program visits every hashref in this data structure (including the top level) and runs the callback.
Callbacks in Perl are code references. These can be created in two ways. We're doing the anonymous subroutine (sometimes called lambda function in other languages). The callback gets passed two arguments: the visitor object and the current data substructure.
We'll iterate all the keys we want to find and simply check if they exist in that current data structure. If we see one, we count it's existence in the %seen hash. Using a hash to store things we have seen is a common idiom in Perl.
We're using a postfix if here, which is convenient and easy to read. %seen is a hash, so we access the value behind the $key with $seen{$key}, while $data is a hash reference, so we use the dereferencing operator -> to access the value behind $key with $data->{$key}.
The callback needs us to return the $data again so it continues. The last line is just there, it's not important.
I've used Data::Printer to output the %seen hash because it's convenient. You can also use Data::Dumper if you want. In production, you will not need that.
use strict;
use warnings;
use Data::Printer;
use Data::Visitor::Callback;
my $from_json = {
"localDate" => "Wednesday 23rd November 2016 11:03:37 PM",
"utcDate" => "Wednesday 23rd November 2016 11:03:37 PM",
"format" => "l jS F Y h:i:s A",
"returnType" => "json",
"timestamp" => 1479942217,
"timezone" => "UTC",
"daylightSavingTime" =>
0, # this was false, I used 0 because that's a non-true value
"url" => "http:\/\/www.convert-unix-time.com?t=1479942217",
"subkey" => {
"altTimestamp" => 1479942217,
"altSubkey" => {
"thirdTimestamp" => 1479942217
}
}
};
my #keys_to_find = qw(timestamp altTimestamp thirdTimestamp missingTimestamp);
my %seen;
my $visitor = Data::Visitor::Callback->new(
hash => sub {
my ( $visitor, $data ) = #_;
foreach my $key (#keys_to_find) {
$seen{$key}++ if exists $data->{$key};
}
return $data;
},
);
$visitor->visit($from_json);
p %seen;
The program outputs the following. Note this is not a Perl data structure. Data::Printer is not a serializer, it's a tool to make data human readable in a convenient way.
{
altTimestamp 1,
thirdTimestamp 1,
timestamp 1
}
Since you also wanted to constraint the input, here's an example how to do that. The following program is a modification of the one above. It allows to give a set of different constraints for every required key.
I've done that by using a dispatch table. Essentially, that's a hash that contains code references. Kind of like the callbacks we use for the Visitor.
The constraints I've included are doing some things with dates. An easy way to work with dates in Perl is the core module Time::Piece. There are lots of questions around here about various date things where Time::Piece is the answer.
I've only done one constraint per key, but you could easily include several checks in those code refs, or make a list of code refs and put them in an array ref (keys => [ sub(), sub(), sub() ]) and then iterate that later.
In the visitor callback we are now also keeping track of the keys that have %passed the constraints check. We're calling the coderef with $coderef->($arg). If a constraint check returns a true value, it gets noted in the hash.
use strict;
use warnings;
use Data::Printer;
use Data::Visitor::Callback;
use Time::Piece;
use Time::Seconds; # for ONE_DAY
my $from_json = { ... }; # same as above
# prepare one of the constraints
# where I'm from, Christmas eve is considered Christmas
my $christmas = Time::Piece->strptime('24 Dec 2016', '%d %b %Y');
# set up the constraints per required key
my %constraints = (
timestamp => sub {
my ($epoch) = #_;
# not older than one day
return $epoch < time && $epoch > time - ONE_DAY;
},
altTimestamp => sub {
my ($epoch) = #_;
# epoch value should be an even number
return ! $epoch % 2;
},
thirdTimestamp => sub {
my ($epoch) = #_;
# before Christmas 2016
return $epoch < $christmas;
},
);
my %seen;
my %passed;
my $visitor = Data::Visitor::Callback->new(
hash => sub {
my ( $visitor, $data ) = #_;
foreach my $key (%constraints) {
if ( exists $data->{$key} ) {
$seen{$key}++;
$passed{$key}++ if $constraints{$key}->( $data->{$key} );
}
}
return $data;
},
);
$visitor->visit($from_json);
p %passed;
The output this time is:
{
thirdTimestamp 1,
timestamp 1
}
If you want to learn more about the dispatch tables, take a look at chapter two of the book Higher Order Perl by Mark Jason Dominus which is legally available for free here.

Replace variables extracted from database with theirs values

I'd like to translate a perl web site in several languages. I search for and tried many ideas, but I think the best one is to save all translations inside the mySQL database. But I get a problem...
When a sentence extracted from the database contains a variable (scalar), it prints on the web page as a scalar:
You have $number new messages.
Is there a proper way to reassign $number its actual value ?
Thank you for your help !
You can use printf format strings in your database and pass in values to that.
printf allows you to specify the position of the argument so only have know what position with the list of parameters "$number" is.
For example
#!/usr/bin/perl
use strict;
my $Details = {
'Name' => 'Mr Satch',
'Age' => '31',
'LocationEn' => 'England',
'LocationFr' => 'Angleterre',
'NewMessages' => 20,
'OldMessages' => 120,
};
my $English = q(
Hello %1$s, I see you are %2$s years old and from %3$s
How are you today?
You have %5$i new messages and %6$i old messages
Have a nice day
);
my $French = q{
Bonjour %1$s, je vous vois d'%4$s et âgés de %2$s ans.
Comment allez-vous aujourd'hui?
Vous avez %5$i nouveaux messages et %6$i anciens messages.
Bonne journée.
};
printf($English, #$Details{qw/Name Age LocationEn LocationFr NewMessages OldMessages/});
printf($French, #$Details{qw/Name Age LocationEn LocationFr NewMessages OldMessages/});
This would be a nightmare to maintain so an alternative might be to include an argument list in the database:
#!/usr/bin/perl
use strict;
sub fetch_row {
return {
'Format' => 'You have %i new messages and %i old messages' . "\n",
'Arguments' => 'NewMessages OldMessages',
}
}
sub PrintMessage {
my ($info,$row) = #_;
printf($row->{'Format'},#$info{split(/ +/,$row->{'Arguments'})});
}
my $Details = {
'Name' => 'Mr Satch',
'Age' => '31',
'LocationEn' => 'England',
'LocationFr' => 'Angleterre',
'NewMessages' => 20,
'OldMessages' => 120,
};
my $row = fetch_row();
PrintMessage($Details,$row)

How do I cleanly extract MySQL enum values in Perl?

I have some code which needs to ensure some data is in a mysql enum prior to insertion in the database. The cleanest way I've found of doing this is the following code:
sub enum_values {
my ( $self, $schema, $table, $column ) = #_;
# don't eval to let the error bubble up
my $columns = $schema->storage->dbh->selectrow_hashref(
"SHOW COLUMNS FROM `$table` like ?",
{},
$column
);
unless ($columns) {
X::Internal::Database::UnknownColumn->throw(
column => $column,
table => $table,
);
}
my $type = $columns->{Type} or X::Panic->throw(
details => "Could not determine type for $table.$column",
);
unless ( $type =~ /\Aenum\((.*)\)\z/ ) {
X::Internal::Database::IncorrectTypeForColumn->throw(
type_wanted => 'enum',
type_found => $type,
);
}
$type = $1;
require Text::CSV_XS;
my $csv = Text::CSV_XS->new;
$csv->parse($type) or X::Panic->throw(
details => "Could not parse enum CSV data: ".$csv->error_input,
);
return map { /\A'(.*)'\z/; $1 }$csv->fields;
}
We're using DBIx::Class. Surely there is a better way of accomplishing this? (Note that the $table variable is coming from our code, not from any external source. Thus, no security issue).
No need to be so heroic. Using a reasonably modern version of DBD::mysql, the hash returned by DBI's column info method contains a pre-split version of the valid enum values in the key mysql_values:
my $sth = $dbh->column_info(undef, undef, 'mytable', '%');
foreach my $col_info ($sth->fetchrow_hashref)
{
if($col_info->{'TYPE_NAME'} eq 'ENUM')
{
# The mysql_values key contains a reference to an array of valid enum values
print "Valid enum values for $col_info->{'COLUMN_NAME'}: ",
join(', ', #{$col_info->{'mysql_values'}}), "\n";
}
...
}
I'd say using Text::CSV_XS may be an overkill, unless you have weird things like commas in enums (a bad idea anyway if you ask me). I'd probably use this instead.
my #fields = $type =~ / ' ([^']+) ' (?:,|\z) /msgx;
Other than that, I don't think there are shortcuts.
I spent part of the day asking the #dbix-class channel over on MagNet the same question and came across this lack of answer. Since I found the answer and nobody else seems to have done so yet, I'll paste the transcript below the TL;DR here:
my $cfg = new Config::Simple( $rc_file );
my $mysql = $cfg->get_block('mysql');
my $dsn =
"DBI:mysql:database=$mysql->{database};".
"host=$mysql->{hostname};port=$mysql->{port}";
my $schema =
DTSS::CDN::Schema->connect( $dsn, $mysql->{user}, $mysql->{password} );
my $valid_enum_values =
$schema->source('Cdnurl')->column_info('scheme')->{extra}->{list};
And now the IRC log of me beating my head against a wall:
14:40 < cj> is there a cross-platform way to get the valid values of an
enum?
15:11 < cj> it looks like I could add 'InflateColumn::Object::Enum' to the
__PACKAGE__->load_components(...) list for tables with enum
columns
15:12 < cj> and then call values() on the enum column
15:13 < cj> but how do I get dbic-dump to add
'InflateColumn::Object::Enum' to
__PACKAGE__->load_components(...) for only tables with enum
columns?
15:20 < cj> I guess I could just add it for all tables, since I'm doing
the same for InflateColumn::DateTime
15:39 < cj> hurm... is there a way to get a column without making a
request to the db?
15:40 < cj> I know that we store in the DTSS::CDN::Schema::Result::Cdnurl
class all of the information that I need to know about the
scheme column before any request is issued
15:42 <#ilmari> cj: for Pg and mysql Schema::Loader will add the list of
valid values to the ->{extra}->{list} column attribute
15:43 <#ilmari> cj: if you're using some other database that has enums,
patches welcome :)
15:43 <#ilmari> or even just a link to the documentation on how to extract
the values
15:43 <#ilmari> and a willingness to test if it's not a database I have
access to
15:43 < cj> thanks, but I'm using mysql. if I were using sqlite for this
project, I'd probably oblige :-)
15:44 <#ilmari> cj: to add components to only some tables, use
result_components_map
15:44 < cj> and is there a way to get at those attributes without making a
query?
15:45 < cj> can we do $schema->resultset('Cdnurl') without having it issue
a query, for instance?
15:45 <#ilmari> $result_source->column_info('colname')->{extra}->{list}
15:45 < cj> and $result_source is $schema->resultset('Cdnurl') ?
15:45 <#ilmari> dbic never issues a query until you start retrieving the
results
15:45 < cj> oh, nice.
15:46 <#ilmari> $schema->source('Cdnurl')
15:46 <#ilmari> the result source is where the result set gets the results
from when they are needed
15:47 <#ilmari> names have meanings :)