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David Precious > Dancer-Plugin-SimpleCRUD-0.70 > Dancer::Plugin::SimpleCRUD



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Module Version: 0.70   Source   Latest Release: Dancer-Plugin-SimpleCRUD-1.15


Dancer::Plugin::SimpleCRUD - very simple CRUD (create/read/update/delete)


A plugin for Dancer web applications, to use a few lines of code to create appropriate routes to support creating/editing/deleting/viewing records within a database table. Uses CGI::FormBuilder to generate, process and validate forms, Dancer::Plugin::Database for database interaction and HTML::Table::FromDatabase to display lists of records.

Setting up forms and code to display and edit database records is a very common requirement in web apps; this plugin tries to make something basic trivially easy to set up and use.


    # In your Dancer app,
    use Dancer::Plugin::SimpleCRUD;

    # Simple example:
        record_title => 'Widget',
        prefix => '/widgets',
        db_table => 'widgets',
        editable => 1,

    # The above would create a route to handle C</widgets>, listing all widgets,
    # with options to add/edit entries (linking to C</widgets/add> and
    # C</widgets/edit/:id> respectively) where a form to add a new entry or edit
    # an existing entry will be created.
    # All fields in the database table would be editable.

    # A more in-depth synopsis, using all options (of course, usually you'd only
    # need to use a few of the options where you need to change the default
    # behaviour):

        record_title => 'Team',
        prefix => '/teams',
        db_table => 'team',
        labels => {     # More human-friendly labels for some columns
            venue_id => 'Home Venue',
            name     => 'Team Name', 
        validation => {  # validate values entered for some columns
            division => qr/\d+/,
        input_types => {  # overriding form input type for some columns
            supersecret => 'password',
            lotsoftext' => 'textarea',
        key_column => 'id', # id is default anyway
        editable_columns => [ qw( venue_id name division )    ],
        display_columns  => [ qw( id venue_id name division ) ],
        deleteable => 1,
        editable => 1,
        sortable => 1,
        paginate => 300,
        template => '',
        query_auto_focus => 1,
        downloadable => 1,
        foreign_keys => {
            columnname => {
                table => 'venues',
                key_column => 'id',
                label_column => 'name',


This plugin provides a simple_crud keyword, which takes a hash of options as described below, and sets up the appropriate routes to present add/edit/delete options.


The options you can pass to simple_crud are:

record_title (required)

What we're editing, for instance, if you're editing widgets, use 'Widget'. Will be used in form titles (for instance "Add a ...", "Edit ..."), and button labels.

prefix (required)

The prefix for the routes which will be created. Given a prefix of /widgets, then you can go to /widgets/new to create a new Widget, and /widgets/42 to edit the widget with the ID (see keu_column) 42.

db_table (required)

The name of the database table.

key_column (optional, default: 'id')

Specify which column in the table is the primary key. If not given, defaults to id.

db_connection_name (optional)

We use Dancer::Plugin::Database to obtain database connections. This option allows you to specify the name of a connection defined in the config file to use. See the documentation for Dancer::Plugin::Database for how multiple database configurations work. If this is not supplied or is empty, the default database connection details in your config file will be used - this is often what you want, so unless your app is dealing with multiple DBs, you probably won't need to worry about this option.

labels (optional)

A hashref of field_name => 'Label', if you want to provide more user-friendly labels for some or all fields. As we're using CGI::FormBuilder, it will do a reasonable job of figuring these out for itself usually anyway - for instance, a field named first_name will be shown as First Name.

input_types (optional)

A hashref of field_name => input type, if you want to override the default type of input which would be selected by CGI::FormBuilder or by our DWIMmery (by default, password fields will be used for field names like 'password', 'passwd' etc, and text area inputs will be used for columns with type 'TEXT').

Valid values include anything allowed by HTML, e.g. text, select, textarea, radio, checkbox, password, hidden.


    input_types => {
        first_name => 'text',
        secret     => 'password',
        gender     => 'radio',
validation (optional)

A hashref of field_name => validation criteria which should be passed to CGI::FormBuilder.


    validation => {
        email_address => 'EMAIL',
        age => '/^\d+$/',
message (optional)

A hashref of field_name => messages to show if validation failed.

Default is "Invalid entry".


    message => {
        age   => 'Please enter your age in years',
        email => 'That is not a valid email address',
jsmessage (optional)

A hashref of field_name => message to show when Javascript validation fails.

Default message is "- Invalid entry for the "$fieldname" field". See above for example.

acceptable_values (optional)

A hashref of arrayrefs to declare that certain fields can take only a set of acceptable values.


    acceptable_values => {
        gender => ['Male', 'Female'],
        status => [qw(Alive Dead Zombie Unknown)],
editable_columns (optional)

Specify an arrayref of fields which the user can edit. By default, this is all columns in the database table, with the exception of the key column.

<not_editable_columns> (optional)

Specify an arrayref of fields which should not be editable.

required (optional)

Specify an arrayref of fields which must be completed. If this is not provided, DWIMmery based on whether the field is set to allow null values in the database will be used - i.e. if that column can contain null, then it doesn't have to be completed, otherwise, it does.


Specify whether to support deleting records. If set to a true value, a route will be created for /prefix/delete/:id to delete the record with the ID given, and the edit form will have a "Delete $record_title" button.


Specify whether to support editing records. Defaults to true. If set to a false value, it will not be possible to add or edit rows in the table.


Specify whether to support sorting the table. Defaults to false. If set to a true value, column headers will become clickable, allowing the user to sort the output by each column, and with ascending/descending order.


Specify whether to show results in pages (with next/previous buttons). Defaults to undef, meaning all records are shown on one page (not useful for large tables). When defined as a number, only this number of results will be shown.


Specify an arrayref of columns that should show up in the list. Defaults to all.


Specify a template that will be applied to all output. This template must have a "simple_crud" placeholder defined or you won't get any output. This template must be located in your "views" directory.

Any global layout will be applied automatically because this option causes the module to use the template keyword. If you don't use this option, the template keyword is not used, which implies that any before_template_render and after_template_render hooks won't be called.


Specify whether to automatically set input focus to the query input field. Defaults to true. If set to a false value, focus will not be set. The focus is set using a simple inlined javascript.


Specify whether to support downloading the results. Defaults to false. If set to a true value, The results show on the HTML page can be downloaded as CSV/TSV/JSON/XML. The download links will appear at the top of the page.

item foreign_keys

A hashref to specify columns in the table which are foreign keys; for each one, the value should be a hashref containing the keys table, key_column and label_column.

DWIMmery ^

This module tries to do what you'd expect it to do, so you can rock up your web app with as little code and effort as possible, whilst still giving you control to override its decisions wherever you need to.

Field types

CGI::FormBuilder is excellent at working out what kind of field to use by itself, but we give it a little help where needed. For instance, if a field looks like it's supposed to contain a password, we'll have it rendered as a password entry box, rather than a standard text box.

If the column in the database is an ENUM, we'll limit the choices available for this field to the choices defined by the ENUM list. (Unless you've provided a set of acceptable values for this field using the acceptable_values option to simple_crud, in which case what you say goes.)

Hooks ^


Fires right before a row is added/edited; receives a hashref of column => value which can be modified if you want to massage the data first.

For instance, if you were dealing with a users table, you might want to take the password entered and hash it, perhaps.


David Precious, <>


Alberto Simões (ambs)


Johnathan Barber



Paul Johnson (pjcj)


Please report any bugs or feature requests to bug-dancer-plugin-simplecrud at, 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.


This module is developed on Github:

Bug reports, ideas, suggestions, patches/pull requests all welcome.

Even just a quick "Hey, this is great, thanks" or "This is no good to me because..." is greatly appreciated. It's always good to know if people are using your code, and what they think.


You can find documentation for this module with the perldoc command.

    perldoc Dancer::Plugin::SimpleCRUD

You may find help with this module on the main Dancer IRC channel or mailing list - see

You can also look for information at:


Copyright 2010-12 David Precious.

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See for more information.

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