README for CGI::Application::Plugin::Output::XSV INSTALLATION To install this module, run the following commands: perl Build.PL ./Build ./Build test ./Build install Alternatively, if you do not have Module::Build but you do have 'make', you can used the included Makefile.PL and run the following commands: perl Makefile.PL make make test make install DEPENDENCIES This module requires these other CPAN modules: CGI::Application Text::CSV_XS NAME CGI::Application::Plugin::Output::XSV - generate csv output from a CGI::Application runmode SYNOPSIS use CGI::Application::Plugin::Output::XSV; ... # in some runmode... # $sth is a prepared DBI statement handle my $members = $sth->fetchall_arrayref( {} ); my @headers = qw( member_id first_name last_name ... ); return $self->xsv_report_web({ fields => \@headers, values => $members, csv_opts => { sep_char => "\t" }, filename => 'members.csv', }); # or, generate the list on the fly: sub get_members { $sth->fetchrow_arrayref() } return $self->xsv_report_web({ iterator => \&get_members, csv_opts => { sep_char => "\t" }, filename => 'members.csv', }); DESCRIPTION "CGI::Application::Plugin::Output::XSV" provides csv-related routines useful for web applications (via Text::CSV_XS). A method, "xsv_report_web" is exported by default. Three other functions, "xsv_report", "clean_field_names", and "add_to_xsv" are available for optional export. You may export all four routines by specifying the export tag ":all": use CGI::Application::Plugin::Output::XSV qw(:all); PURPOSE On many websites, I had code to retrieve a list of data items for use in an HTML::Template TMPL_LOOP. Usually this code would use the DBI routine "fetchall_arrayref()" to get a list of hash references, one for each data item. my $users = $sth->fetchall_arrayref( {} ); my $template = $self->load_tmpl( ... ); $template->param( users => $users ); return $template->output; At some point, it would become apparent that an "export to spreadsheet" feature would be useful, so I'd add another runmode, which almost always looked the same: my @fields = qw(keys to each data item); my $csv = Text::CSV_XS->new(); foreach my $user ( @{$users} ) { $csv->combine( [ @{$user}{@fields} ] ); $output .= $csv->string() . "\n"; } $self->header_props( -type => 'application/x-csv', '-content-disposition' => "attachment; filename=export.csv", ); return $output; The purpose of this module is to provide a simple method, "xsv_report_web", that wraps the above code while offering a fair amount of programmer flexibility. For example, the programmer may control the naming of header columns, filter each row of data before it is passed to Text::CSV_XS, and set the filename that is supplied to the user's browser. Please see the documentation below for "xsv_report_web" for a list of available options. METHODS xsv_report_web ## METHOD 1. Pre-generated list of values for csv # in a runmode my @members = ( { member_id => 1, first_name => 'Chuck', last_name => 'Berry', }, ... ); my @headers = ("Member ID", "First Name", "Last Name"); my @fields = qw(member_id first_name last_name); return $self->xsv_report_web({ fields => \@fields, headers => \@headers, values => \@members, csv_opts => { sep_char => "\t" }, filename => 'members.csv', }); ## METHOD 2. Generate list on the fly # in a runmode sub get_members { $sth->fetchrow_arrayref() } my @headers = ("Member ID", "First Name", "Last Name"); return $self->xsv_report_web({ headers => \@headers, iterator => \&get_members, csv_opts => { sep_char => "\t" }, filename => 'members.csv', stream => 1, }); This method generates a csv file that is sent directly to the user's web browser. It sets the content-type header to 'application/x-csv' and sets the content-disposition header to 'attachment'. It should be invoked through a CGI::Application subclass object. It takes a reference to a hash of named parameters. All except for "values" or "iterator" are optional: csv_opts csv_opts => { sep_char => "\t" }, A reference to a hash of options passed to the constructor of Text::CSV_XS. The default is an empty hash. fields fields => [ qw(member_id first_name last_name) ], # or array indices fields => [ 1, 2, 0 ], A reference to a list of field names or array indices. This parameter specifies the order of fields in each row of output. If "fields" is not supplied, a list will be generated using the first entry in the "values" list. Note, however, that in this case, if the "values" parameter is a list of hashes, the field order will be random because the field names are extracted from a hash. If the "values" parameter is a list of lists, the field order will be the same as the data provided. If "fields" is not supplied and "iterator" is used instead of "values", the field list will be empty. filename filename => 'members.csv', The name of the file which will be sent in the HTTP content-disposition header. The default is "download.csv". headers headers => [ "Member ID", "First Name", "Last Name" ], A reference to a list of column headers to be used as the first row of the csv report. If "headers" is not supplied (and "include_headers" is not set to a false value), "headers_cb" will be called with "fields" as a parameter to generate column headers. headers_cb # replace underscores with spaces headers_cb => sub { my $fields = shift; # using temp var to avoid modifying $fields my @fields_copy = @{$fields}; return [ map { tr/_/ /; $_ } @fields_copy ]; }, A reference to a subroutine used to generate column headers from the field names. A default routine is provided in "clean_field_names". This function is passed a reference to the list of fields ("fields") as a parameter and should return a reference to a list of column headers. include_headers include_headers => 1, A true or false value indicating whether to include "headers" (or automatically generated headers) as the first row of output. The default is true. line_ending line_ending => "\n", The value appended to each line of csv output. The default is "\n". values values => [ { member_id => 1, first_name => 'Chuck', last_name => 'Berry', }, ], # or a list of lists values => [ [ 1, 'Chuck', 'Berry', ], ], A reference to a list of hash references (such as that returned by the DBI "fetchall_arrayref( {} )" routine), or a reference to a list of list references. Either this argument or "iterator" must be provided. iterator iterator => sub { $sth->fetchrow_arrayref() }, A reference to a subroutine that is used to generate each row of data. It is passed a reference to the list of fields ("fields") as a parameter and should return a reference to a list (which will be passed to "add_to_xsv()"). It will be called repeatedly to generate each row of data until it returns a false value. This may be preferred to "values" when the data set is large or expensive to generate up-front. Thanks to Mark Stosberg for suggesting this option. Either this argument or "values" must be provided. maximum_iters maximum_iters => 1_000_000, This is the maximum number of times the "iterator" will be called before an exception is raised. This is a basic stopgap to prevent a runaway iterator that never returns false. The default is one million. row_filter # uppercase all values # (each row is a list of hash references) row_filter => sub { my ($row, $fields) = @_; return [ map { uc } @{$row}{@$fields} ]; }, A reference to a subroutine used to filter each row of data (other than the header row) before it is passed to "add_to_xsv". When the "values" parameter is supplied, a default filter is provided that produces each row in the order specified by "headers". For example, the default filter for a "values" list of hash references is shown below. row_filter => sub { my ($row, $fields) = @_; return [ @{$row}{@$fields} ]; }, This subroutine is passed two parameters for each row: * the current row (reference to a list of hashes or lists) * the field list ("fields" - reference to a list of hash keys or array indices) Note: This parameter used to be named "get_row_cb". That name is deprecated and a warning will be issued if it is used instead of "row_filter". stream stream => 1, This flag controls whether or not output is printed immediately or collected and returned to the caller. Set to a true value to remove buffering on STDOUT and to emit output as it is generated. This can save memory in the case of a large document, for example. The default is false to retain backwards-compatibility. In general, it is probably more efficient to set this to a true value, but note that it breaks with the standard CGI::Application convention of returning generated content from your runmodes rather than printing it yourself. FUNCTIONS add_to_xsv # $sth is a prepared DBI statement handle my $values = $sth->fetchall_arrayref( {} ); my @headers = qw/foo bar baz/; my $output; # $csv is a Text::CSV_XS object foreach my $href ( @{$values} ) { $output .= add_to_xsv( $csv, [ @{$href}{@headers} ], "\r\n" ); } This function, used internally by "xsv_report"/"xsv_report_web", formats a list of values for inclusion a csv file. The return value is from "$csv->string()", where $csv is a Text::CSV_XS object. It takes three parameters: * A Text::CSV_XS object * A reference to a list of values * The line ending On an error from Text::CSV_XS, the function raises an exception. On receiving an empty list of values, the function returns the line ending only. clean_field_names my $fields = [ qw/first_name foo bar baz/ ]; my $headers = clean_field_names( $fields ); # $headers is now [ 'First Name', 'Foo', 'Bar', 'Baz' ] This function takes a reference to a list of strings and returns a reference to a new list in which the strings are reformatted as such: 1. Underscores ('_') are changed to spaces 2. The first letter of each word is capitalized This function is used by "xsv_report" and "xsv_report_web" if the "headers_cb" parameter is not supplied. xsv_report # $sth is a prepared DBI statement handle my $members = $sth->fetchall_arrayref( {} ); my @headers = qw( member_id first_name last_name ... ); my $output = $self->xsv_report({ fields => \@headers, values => $members, csv_opts => { sep_char => "\t" }, }); # do something with $output This function generates a string containing csv data and returns it. This may be useful when you want to do some manipulation of the data before sending it to the user's browser or elsewhere. It takes the same named parameters (via a reference to a hash) as "xsv_report_web" except for "filename", which is not applicable to this function. EXAMPLES Specify (almost) everything return $self->xsv_report_web({ values => [ { first_name => 'Jack', last_name => 'Tors', phone => '555-1212' }, { first_name => 'Frank', last_name => 'Rizzo', phone => '555-1515' }, ], headers => [ "First Name", "Last Name", "Phone" ], fields => [ qw(first_name last_name phone) ], include_headers => 1, line_ending => "\n", csv_opts => { sep_char => "\t" }, filename => 'download.csv', }); __END__ "First Name" "Last Name" Phone Jack Tors 555-1212 Frank Rizzo 555-1515 Use defaults # ends up with same options and output as above return $self->xsv_report_web({ values => [ { first_name => 'Jack', last_name => 'Tors', phone => '555-1212' }, { first_name => 'Frank', last_name => 'Rizzo', phone => '555-1515' }, ], headers => [ "First Name", "Last Name", "Phone" ], fields => [ qw(first_name last_name phone) ], }); Use header generation provided by module # headers generated will be [ "First Name", "Last Name", "Phone" ] # same output as above return $self->xsv_report_web({ values => [ { first_name => 'Jack', last_name => 'Tors', phone => '555-1212' }, { first_name => 'Frank', last_name => 'Rizzo', phone => '555-1515' }, ], fields => [ qw(first_name last_name phone) ], }); Use custom header generation # headers generated will be [ "first", "last", "phone" ] return $self->xsv_report_web({ values => [ { first_name => 'Jack', last_name => 'Tors', phone => '555-1212' }, { first_name => 'Frank', last_name => 'Rizzo', phone => '555-1515' }, ], fields => [ qw(first_name last_name phone) ], headers_cb => sub { my @h = @{ +shift }; s/_name$// foreach @h; return \@h; }, }); __END__ first,last,phone Jack,Tors,555-1212 Frank,Rizzo,555-1515 If order of fields doesn't matter # headers and fields will be in random order (but consistent # throughout data processing) due to extraction from hash # (headers will be generated automatically) return $self->xsv_report_web({ values => [ { first_name => 'Jack', last_name => 'Tors', phone => '555-1212' }, { first_name => 'Frank', last_name => 'Rizzo', phone => '555-1515' }, ], }); __END__ Phone,"Last Name","First Name" 555-1212,Tors,Jack 555-1515,Rizzo,Frank No header row return $self->xsv_report_web({ values => [ { first_name => 'Jack', last_name => 'Tors', phone => '555-1212' }, { first_name => 'Frank', last_name => 'Rizzo', phone => '555-1515' }, ], fields => [ qw(first_name last_name phone) ], include_headers => 0, }); __END__ Jack,Tors,555-1212 Frank,Rizzo,555-1515 Filter data as it is processed sub plus_one { my ($row, $fields) = @_; return [ map { $_ + 1 } @{$row}{@$fields} ]; } # each row (other than header row) will be # passed through plus_one() return $self->xsv_report_web({ fields => [ qw(foo bar baz) ], values => [ { foo => 1, bar => 2, baz => 3 }, ], row_filter => \&plus_one, }); __END__ Foo,Bar,Baz 2,3,4 Pass list of lists (instead of hashes) # each row will be processed in order # since fields parameter is omitted $self->xsv_report_web({ include_headers => 0, values => [ [ 1, 2, 3 ], [ 4, 5, 6 ], ], }); __END__ 1,2,3 4,5,6 Generate each row on the fly my @vals = qw(one two three four five six); sub get_vals { while ( @vals ) { return [ splice @vals, 0, 3 ] } }; $self->xsv_report_web({ include_headers => 0, iterator => \&get_vals, }); __END__ one,two,three four,five,six Generate each row on the fly using a DBI iterator my $get_vals = sub { $sth->fetchrow_arrayref() }; $self->xsv_report_web({ include_headers => 0, iterator => $get_vals, }); Use a DBI iterator, increment each value extracted $self->xsv_report_web({ include_headers => 0, iterator => sub { $sth->fetchrow_arrayref() }; row_filter => sub { my $row = shift; return [ map { $_ + 1 } @{$row} ]; }, }); ERROR HANDLING The function "add_to_xsv" will raise an exception when "Text::CSV_XS->combine" fails. Please see the Text::CSV_XS documentation for details about what type of input causes a failure. AUTHOR Evan A. Zacks "" BUGS Please report any bugs or feature requests to "bug-cgi-application-plugin-output-xsv@rt.cpan.org", or through the web interface at . I will be notified, and then you'll automatically be notified of progress on your bug as I make changes. SEE ALSO Text::CSV_XS, CGI::Application COPYRIGHT AND LICENSE Copyright (c) 2006,2010 CommonMind, LLC. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.