CGI::Ex::App - Anti-framework application framework.
+=head1 SYNOPSIS
+
+A basic example:
+
+ -------- File: /cgi-bin/my_cgi --------
+
+ #!/usr/bin/perl -w
+
+ use strict;
+ use base qw(CGI::Ex::App);
+
+ __PACKAGE__->navigate;
+ exit;
+
+ sub main_file_print {
+ return \ "Hello World!";
+ }
+
+Well, you should put your content in an external file...
+
+ -------- File: /cgi-bin/my_cgi --------
+
+ #!/usr/bin/perl -w
+
+ use strict;
+ use base qw(CGI::Ex::App);
+
+ __PACKAGE__->navigate;
+
+ sub base_dir_abs { '/var/www/templates' }
+
+
+ -------- File: /var/www/templates/my_cgi/main.html --------
+
+ Hello World!
+
+How about if we want to add substitutions...
+
+ -------- File: /cgi-bin/my_cgi --------
+
+ #!/usr/bin/perl -w
+
+ use strict;
+ use base qw(CGI::Ex::App);
+
+ __PACKAGE__->navigate;
+
+ sub base_dir_abs { '/var/www/templates' }
+
+ sub main_hash_swap {
+ my $self = shift;
+ return {
+ greeting => 'Hello',
+ date => sub { scalar localtime },
+ };
+ }
+
+
+ -------- File: /var/www/templates/my_cgi/main.html --------
+
+ [% greeting %] World! ([% date %])
+
+
+How about a form with validation (inluding javascript validation)...
+
+ -------- File: /cgi-bin/my_cgi --------
+
+ #!/usr/bin/perl -w
+
+ use strict;
+ use base qw(CGI::Ex::App);
+
+ __PACKAGE__->navigate;
+
+ sub base_dir_abs { '/var/www/templates' }
+
+ sub main_hash_swap { {date => sub { scalar localtime }} }
+
+ sub main_hash_fill {
+ return {
+ guess => 50,
+ };
+ }
+
+ sub main_hash_validation {
+ return {
+ guess => {
+ required => 1,
+ compare1 => '<= 100',
+ compare1_error => 'Please enter a value less than 101',
+ compare2 => '> 0',
+ compare2_error => 'Please enter a value greater than 0',
+ },
+ };
+ }
+
+ sub main_finalize {
+ my $self = shift;
+ my $form = $self->form;
+
+ $self->add_to_form({was_correct => ($form->{'guess'} == 23)});
+
+ return 0; # indicate to show the page without trying to move along
+ }
+
+
+ -------- File: /var/www/templates/my_cgi/main.html --------
+
+ <h2>Hello World! ([% date %])</h2>
+
+ [% IF was_correct %]
+ <b>Correct!</b> - The number was [% guess %].<br>
+ [% ELSIF guess %]
+ <b>Incorrect</b> - The number was not [% guess %].<br>
+ [% END %]
+
+ <form name="[% form_name %]" method="post">
+
+ Enter a number between 1 and 100: <input type="text" name="guess"><br>
+ <span id="guess_error" style="color:red">[% guess_error %]</span><br>
+
+ <input type="submit">
+ </form>
+
+ [% js_validation %]
+
+
+There are infinite possibilities. There is a longer "SYNOPSIS" after
+the process flow discussion and more examples near the end of this
+document. It is interesting to note that there have been no databases
+so far. CGI::Ex::App is Controller/Viewer that is somewhat Model
+agnostic.
+
=head1 DESCRIPTION
-Fill in the blanks and get a ready made web application. This module
-is somewhat similar in spirit to CGI::Application, CGI::Path, and
-CGI::Builder and any other "CGI framework." As with the others,
-CGI::Ex::App tries to do as much of the mundane things, in a simple
-manner, without getting in the developer's way. Your mileage may vary.
+Fill in the blanks and get a ready made web application.
+
+This module is somewhat similar in spirit to CGI::Application,
+CGI::Path, and CGI::Builder and any other "CGI framework." As with
+the others, CGI::Ex::App tries to do as much of the mundane things, in
+a simple manner, without getting in the developer's way. However,
+there are various design patterns for CGI applications that
+CGI::Ex::App handles for you that the other frameworks require you to
+bring in extra support. The entire CGI::Ex suite has been taylored to
+work seamlessly together. Your mileage in building applications may
+vary.
+
+If you build applications that submit user information, validate it,
+re-display it, fill in forms, or separate logic into separate modules,
+then this module may be for you. If all you need is a dispatch
+engine, then this still may be for you. If all you want is to look at
+user passed information, then this may still be for you. If you like
+writing bare metal code, this could still be for you. If you don't want
+to write any code, this module will help - but you still need to
+provide your key actions and html.
+
+One of the great benefits of CGI::Ex::App vs. Catalyst or Rails style
+frameworks is that the model of CGI::Ex::App can be much more abstract.
+And models often are abstract.
+
+=head1 DEFAULT PROCESS FLOW
+
+The following pseudo-code describes the process flow
+of the CGI::Ex::App framework. Several portions of the flow
+are encapsulated in hooks which may be completely overridden to give
+different flow. All of the default actions are shown. It may look
+like a lot to follow, but if the process is broken down into the
+discrete operations of step iteration, data validation, and template
+printing the flow feels more natural.
+
+=head2 navigate
+
+The process starts off by calling ->navigate.
+
+ navigate {
+ eval {
+ ->pre_navigate
+ ->nav_loop
+ ->post_navigate
+ }
+ # dying errors will run the ->handle_error method
+
+ ->destroy
+ }
+
+=head2 nav_loop
+
+The nav_loop method will run as follows:
+
+ nav_loop {
+ ->path (get the array of path steps)
+ # ->path_info_map_base (method - map ENV PATH_INFO to form)
+ # look in ->form for ->step_key
+ # make sure step is in ->valid_steps (if defined)
+
+ ->pre_loop($path)
+ # navigation stops if true
+
+ foreach step of path {
+
+ ->morph
+ # check ->allow_morph
+ # check ->allow_nested_morph
+ # ->morph_package (hook - get the package to bless into)
+ # ->fixup_after_morph if morph_package exists
+ # if no package is found, process continues in current file
+
+ ->path_info_map (hook - map PATH_INFO to form)
+
+ ->run_step (hook)
+
+ ->refine_path (hook)
+ # only called if run_step returned false (page not printed)
+ ->next_step (hook) # find next step and add to path
+ ->set_ready_validate(0) (hook)
+
+ ->unmorph
+ # only called if morph worked
+ # ->fixup_before_unmorph if blessed to current package
+
+ # exit loop if ->run_step returned true (page printed)
+
+ } end of foreach step
+
+ ->post_loop
+ # navigation stops if true
+
+ ->default_step
+ ->insert_path (puts the default step into the path)
+ ->nav_loop (called again recursively)
+
+ } end of nav_loop
+
+=head2 run_step (hook)
+
+For each step of the path the following methods will be run
+during the run_step hook.
+
+ run_step {
+ ->pre_step (hook)
+ # exits nav_loop if true
+
+ ->skip (hook)
+ # skips this step if true (stays in nav_loop)
+
+ ->prepare (hook - defaults to true)
+
+ ->info_complete (hook - ran if prepare was true)
+ ->ready_validate (hook)
+ return false if ! ready_validate
+ ->validate (hook - uses CGI::Ex::Validate to validate form info)
+ ->hash_validation (hook)
+ ->file_val (hook)
+ ->base_dir_abs
+ ->base_dir_rel
+ ->name_module
+ ->name_step
+ ->ext_val
+ returns true if validate is true or if nothing to validate
+
+ ->finalize (hook - defaults to true - ran if prepare and info_complete were true)
+
+ if ! ->prepare || ! ->info_complete || ! ->finalize {
+ ->prepared_print
+ ->hash_base (hook)
+ ->hash_common (hook)
+ ->hash_form (hook)
+ ->hash_fill (hook)
+ ->hash_swap (hook)
+ ->hash_errors (hook)
+ # merge form, base, common, and fill into merged fill
+ # merge form, base, common, swap, and errors into merged swap
+ ->print (hook - passed current step, merged swap hash, and merged fill)
+ ->file_print (hook - uses base_dir_rel, name_module, name_step, ext_print)
+ ->swap_template (hook - processes the file with CGI::Ex::Template)
+ ->template_args (hook - passed to CGI::Ex::Template->new)
+ ->fill_template (hook - fills the any forms with CGI::Ex::Fill)
+ ->fill_args (hook - passed to CGI::Ex::Fill::fill)
+ ->print_out (hook - print headers and the content to STDOUT)
+
+ ->post_print (hook - used for anything after the print process)
+
+ # return true to exit from nav_loop
+ }
+
+ ->post_step (hook)
+ # exits nav_loop if true
+
+ } end of run_step
+
+It is important to learn the function and placement of each of the
+hooks in the process flow in order to make the most of CGI::Ex::App.
+It is enough to begin by learning a few common hooks - such as
+hash_validation, hash_swap, and finalize, and then learn about other
+hooks as needs arise. Sometimes, it is enough to simply override the
+run_step hook and take care of processing the entire step yourself.
+
+Because of the hook based system, and because CGI::Ex::App uses
+sensible defaults, it is very easy to override a little or a lot which
+ends up giving the developer a lot of flexibility.
+
+Additionally, it should be possible to use CGI::Ex::App with the other
+frameworks such as CGI::Application or CGI::Prototype. For these you
+could simple let each "runmode" call the run_step hook of CGI::Ex::App
+and you will instantly get all of the common process flow for free.
+
+=head1 MAPPING URI TO STEP
+
+The default out of the box configuration will map URIs to steps as follows:
+
+ # Assuming /cgi-bin/my_app is the program being run
+
+ URI: /cgi-bin/my_app
+ STEP: main
+ FORM: {}
+ WHY: No other information is passed. The path method is
+ called which eventually calls ->default_step which
+ defaults to "main"
+
+ URI: /cgi-bin/my_app?foo=bar
+ STEP: main
+ FORM: {foo => "bar"}
+ WHY: Same as previous example except that QUERY_STRING
+ information was passed and placed in form.
+
+ URI: /cgi-bin/my_app?step=my_step
+ STEP: my_step
+ FORM: {step => "my_step"}
+ WHY: The path method is called which looks in $self->form
+ for the key ->step_key (which defaults to "step").
+
+ URI: /cgi-bin/my_app?step=my_step&foo=bar
+ STEP: my_step
+ FORM: {foo => "bar", step => "my_step"}
+ WHY: Same as before but has other parameters were passed.
+
+ URI: /cgi-bin/my_app/my_step
+ STEP: my_step
+ FORM: {step => "my_step"}
+ WHY: The path method is called which called path_info_map_base
+ which matched $ENV{'PATH_INFO'} using the default regex
+ of qr{^/(\w+)$} and place the result in
+ $self->form->{$self->step_key}. Path then looks in
+ $self->form->{$self->step_key} for the initial step. See
+ the path_info_map_base method for more information.
+
+ URI: /cgi-bin/my_app/my_step?foo=bar
+ STEP: my_step
+ FORM: {foo => "bar", step => "my_step"}
+ WHY: Same as before but other parameters were passed.
+
+ URI: /cgi-bin/my_app/my_step?step=other_step
+ STEP: other_step
+ FORM: {step => "other_step"}
+ WHY: The same procedure took place, but when the PATH_INFO
+ string was matched, the form key "step" already existed
+ and was not replaced by the value from PATH_INFO.
+
+The remaining examples in this section are based on the assumption
+that the following method is installed in your script.
+
+ sub my_step_path_info_map {
+ return [
+ [qr{^/\w+/(\w+)/(\d+)$}, 'foo', 'id'],
+ [qr{^/\w+/(\w+)$}, 'foo'],
+ [qr{^/\w+/(.+)$}, 'anything_else'],
+ ];
+ }
+
+ URI: /cgi-bin/my_app/my_step/bar
+ STEP: my_step
+ FORM: {foo => "bar"}
+ WHY: The step was matched as in previous examples using
+ path_info_map_base. However, the form key "foo"
+ was set to "bar" because the second regex returned
+ by the path_info_map hook matched the PATH_INFO string
+ and the corresponding matched value was placed into
+ the form using the keys specified following the regex.
+
+ URI: /cgi-bin/my_app/my_step/bar/1234
+ STEP: my_step
+ FORM: {foo => "bar", id => "1234"}
+ WHY: Same as the previous example, except that the first
+ regex matched the string. The first regex had two
+ match groups and two form keys specified. Note that
+ it is important to order your match regexes in the
+ order that will match the most data. The third regex
+ would also match this PATH_INFO.
+
+ URI: /cgi-bin/my_app/my_step/some/other/type/of/data
+ STEP: my_step
+ FORM: {anything_else => 'some/other/type/of/data'}
+ WHY: Same as the previous example, except that the third
+ regex matched.
+
+ URI: /cgi-bin/my_app/my_step/bar?bling=blang
+ STEP: my_step
+ FORM: {foo => "bar", bling => "blang"}
+ WHY: Same as the first step, but additional QUERY_STRING
+ information was passed.
+
+ URI: /cgi-bin/my_app/my_step/one%20two?bar=three%20four
+ STEP: my_step
+ FORM: {anything_else => "one two", bar => "three four"}
+ WHY: The third path_info_map regex matched. Note that the
+ %20 in bar was unescaped by CGI::param, but the %20
+ in anything_else was unescaped by Apache. If you are
+ not using Apache, this behavior may vary. CGI::Ex::App
+ doesn't decode parameters mapped from PATH_INFO.
+
+See the path method for more information about finding the initial step
+of the path.
+
+The form method calls CGI::Ex::form which uses CGI::param to retrieve
+GET and POST parameters. See the form method for more information on
+how GET and POST parameters are parsed.
+
+See the path_info_map_base method, and path_info_map hook for more information
+on how the path_info maps function.
+
+Using the following code is very useful for determing what hooks have
+taken place:
+
+ use CGI::Ex::Dump qw(debug);
+
+ sub post_navigate {
+ my $self = shift;
+ debug $self->dump_history, $self->form;
+ }
+
+=head1 ADDING DATA VALIDATION TO A STEP
+
+CGI::Ex::App uses CGI::Ex::Validate for its data validation. See CGI::Ex::Validate
+for more information about the many ways you can validate your data.
+
+The default hash_validation hook returns an empty hashref. This means that passed
+in data is all valid and the script will automatically call the step's finalize method.
+
+The following shows how to some contrived validation to a step called "my_step".
+
+ sub my_step_hash_validation {
+ return {
+ username => {
+ required => 1,
+ match => 'm/^(\w+)$/',
+ match_error => 'The $field field may only contain word characters',
+ max_len => 20,
+ },
+ password => {
+ required => 1,
+ max_len => 15,
+ },
+ password_verify => {
+ validate_if => 'password',
+ equals => 'password',
+ },
+ usertype => {
+ required => 1,
+ enum => [qw(animal vegetable mineral)],
+ },
+ };
+ }
+
+The step will continue to display the html form until all of the fields pass
+validation.
+
+See the hash_validation hook and validate hook for more information about how
+this takes place.
+
+=head1 ADDING JAVASCRIPT DATA VALIDATION TO A STEP
+
+You must first provide a hash_validation hook as explained in the previous section.
+
+Once you have a hash_validation hook, you would place the following tags
+into your HTML template.
+
+ <form name="[% form_name %]" method="post">
+ ...
+ </form>
+ [% js_validation %]
+
+The "form_name" swap-in places a name on the form that the javascript returned by
+the js_validation swap-in will be able to find and check for validity.
+
+See the hash_validation, js_validation, and form_name hooks for more information.
+
+Also, CGI::Ex::validate.js allows for inline errors in addition to or in replacement
+of an alert message. To use inline errors, you must provide an element in your
+HTML document where this inline message can be placed. The common way to do it is as
+follows:
+
+ <input type="text" name="username"><br>
+ <span class="error" id="username_error">[% username_error %]</span>
+
+The span around the error allows for the error css class and it provides a location
+that the Javascript validation can populate with errors. The [% username_error %] provides
+a location for errors generated on the server side to be swapped in. If there was no error
+the [% username_error %] tag would default to "".
+
+=head1 ADDING ADDITIONAL TEMPLATE VARIABLES
+
+All variables returned by the hash_base, hash_common, hash_form, hash_swap, and
+hash_errors hooks are available for swapping in templates.
+
+The following shows how to add variables using the hash_swap hook on the step "main".
+
+ sub main_hash_swap {
+ return {
+ color => 'red',
+ choices => [qw(one two three)],
+ "warn" => sub { warn @_ },
+ };
+ }
+
+You could also return the fields from the hash_common hook and they would be available
+in both the template swapping as well as form filling.
+
+See the hash_base, hash_common, hash_form, hash_swap, hash_errors, swap_template, and
+template_args hooks for more information.
+
+The default template engine used is CGI::Ex::Template which is Template::Toolkit compatible.
+See the CGI::Ex::Template or Template::Toolkit documentation for the types of data
+that can be passed, and for the syntax that can be used.
+
+=head1 ADDING ADDITIONAL FORM FILL VARIABLES
+
+All variables returned by the hash_base, hash_common, hash_form, and hash_fill hooks
+are available for filling html fields in on templates.
+
+The following shows how to add variables using the hash_fill hook on the step "main".
+
+ sub main_hash_fill {
+ return {
+ color => 'red',
+ choices => [qw(one two three)],
+ };
+ }
+
+You could also return the fields from the hash_common hook and they would be available
+in both the form filling as well as in the template swapping.
+
+See the hash_base, hash_common, hash_form, hash_swap, hash_errors, fill_template, and
+fill_args hooks for more information.
+
+The default form filler is CGI::Ex::Fill which is similar to HTML::FillInForm but
+has several benefits. See the CGI::Ex::Fill module for the available options.
+
+=head1 FINDING TEMPLATES AND VALIDATION FILES
+
+CGI::Ex::App tries to help your applications use a good template directory layout, but allows
+for you to override everything.
+
+External template files are used for storing your html templates and
+for storing your validation files (if you use externally stored
+validation files).
+
+The default file_print hook will look for content on your file system,
+but it can also be completely overridden to return a reference to a
+scalar containing the contents of your file. Actually it can return
+anything that CGI::Ex::Template (Template::Toolkit compatible) will
+treat as input. This templated html is displayed to the user during
+any step that enters the "print" phase.
+
+Similarly the default file_val hook will look for a validation file on
+the file system, but it too can return a reference to a scalar
+containing the contents of a validation file. It may actually return
+anything that the CGI::Ex::Validate get_validation method is able to
+understand. This validation is used by the default "info_complete"
+method for verifying if the submitted information passes its specific
+checks. A more common way of inlining validation is to return a
+validation hash from a hash_validation hook override.
+
+If the default file_print and file_val hooks are used, the following methods
+are employed for finding templates and validation files on your filesystem (they
+are also documented more in the HOOKS AND METHODS section.
+
+=over 4
+
+=item base_dir_abs
+
+Absolute path or arrayref of paths to the base templates directory. Default "".
+
+=item base_dir_rel
+
+Relative path inside of the base_dir_abs directory where content can be found. Default "".
+
+=item name_module
+
+Directory inside of base_dir_rel where files for the current CGI (module) will be
+stored. Default value is $ENV{SCRIPT_NAME} with path and extension removed.
+
+=item name_step
+
+Used with ext_print and ext_val for creating the filename that will be looked for
+inside of the name_module directory. Default value is the current step.
+
+=item ext_print and ext_val
+
+Filename extensions added to name_step to create the filename looked for
+inside of the name_module directory. Default is "html" for ext_print and "val"
+for ext_val.
+
+=back
+
+It may be easier to understand the usage of each of these methods by showing
+a contrived example. The following is a hypothetical layout for your templates:
+
+ /home/user/templates/
+ /home/user/templates/chunks/
+ /home/user/templates/wrappers/
+ /home/user/templates/content/
+ /home/user/templates/content/my_app/
+ /home/user/templates/content/my_app/main.html
+ /home/user/templates/content/my_app/step1.html
+ /home/user/templates/content/my_app/step1.val
+ /home/user/templates/content/another_cgi/main.html
+
+In this example we would most likely set values as follows:
+
+ base_dir_abs /home/user/templates
+ base_dir_rel content
+ name_module my_app
+
+The name_module method defaults to the name of the running program, but
+with the path and extension removed. So if we were running
+/cgi-bin/my_app.pl, /cgi-bin/my_app, or /anypath/my_app, then
+name_module would default to "my_app" and we wouldn't have to
+hard code the value. Often it is wise to set the value anyway so
+that we can change the name of the cgi script without effecting
+where template content should be stored.
+
+Continuing with the example and assuming that name of the step that
+the user has requested is "step1" then the following values would be
+returned:
+
+ base_dir_abs /home/user/templates
+ base_dir_rel content
+ name_module my_app
+ name_step step1
+ ext_print html
+ ext_val val
+
+ file_print content/my_app/step1.html
+ file_val /home/user/templates/content/my_app/step1.val
+
+The call to the template engine would look something like
+the following:
-If you build applications that submit user information, validate it,
-re-display it, fill in forms, or separate logic into separate modules,
-then this module may be for you. If all you need is a dispatch
-engine, then this still may be for you. If all want is to look at
-user passed information, then this may still be for you. If you like
-writing bare metal code, this could still be for you. If you don't want
-to write any code, this module will help - but you still need to
-provide you key actions.
+ my $t = $self->template_obj({
+ INCLUDE_PATH => $self->base_dir_abs,
+ });
+
+ $t->process($self->file_print($step), \%vars);
+
+The template engine would then look for the relative file
+inside of the absolute paths (from base_dir_abs).
+The call to the validation engine would pass the absolute
+filename that is returned by file_val.
+
+The name_module and name_step methods can return filenames with
+additional directories included. The previous example could
+also have been setup using the following values:
+
+ base_dir_abs /home/user/templates
+ base_dir_rel
+ name_module content/my_app
+
+In this case the same values would be returned for the file_print and file_val hooks
+as were returned in the previous setup.
=head1 SYNOPSIS (A LONG "SYNOPSIS")
-More examples will come with time. Here are the basics for now.
This example script would most likely be in the form of a cgi, accessible via
the path http://yourhost.com/cgi-bin/my_app (or however you do CGIs on
your system. About the best way to get started is to paste the following
exit;
Note: the "exit" isn't necessary - but it is kind of nice to infer
-that program flow doesn't go beyond the ->navigate call.
+that process flow doesn't go beyond the ->navigate call.
The navigate routine is now going to try and "run" through a series of
steps. Navigate will call the ->path method which should return an
URI '/cgi-bin/my_app?step=foo' would run the step 'foo' first. The
URI '/cgi-bin/my_app/bar' would run the step 'bar' first.
-CGI::Ex::App allows for running steps in a preset path. The navigate
-method will go through a step of the path at a time and see if it is
+CGI::Ex::App allows for running steps in a preset path or each step may
+choose the next step that should follow. The navigate
+method will go through one step of the path at a time and see if it is
completed (various methods determine the definition of "completed").
This preset type of path can also be automated using the CGI::Path
module. Rather than using a preset path, CGI::Ex::App also has
A few things to note about the template:
First, we add a hidden form field called step. This will be filled in
-at a later point with the current step we are on.
+automatically at a later point with the current step we are on.
We provide locations to swap in inline errors.
For more of a real world example, it would be good to read the sample recipe db
application included at the end of this document.
-=head1 DEFAULT PROGRAM FLOW
-
-The following pseudo-code describes the process flow
-of the CGI::Ex::App framework. Several portions of the flow
-are encapsulated in hooks which may be completely overridden to give
-different flow. All of the default actions are shown. It may look
-like a lot to follow, but if the process is broken down into the
-discrete operations of step iteration, data validation, and template
-printing the flow feels more natural.
-
-The process starts off by calling ->navigate.
-
- navigate {
- eval {
- ->pre_navigate
- ->nav_loop
- ->post_navigate
- }
- # dying errors will run the ->handle_error method
- }
-
-The nav_loop method will run as follows:
-
- nav_loop {
- ->path (get the array of path steps)
- # look in $ENV{'PATH_INFO'}
- # look in ->form for ->step_key
- # make sure step is in ->valid_steps (if defined)
-
- ->pre_loop($path)
- # navigation stops if true
-
- foreach step of path {
-
- ->morph
- # check ->allow_morph
- # check ->allow_nested_morph
- # ->morph_package (hook - get the package to bless into)
- # ->fixup_after_morph if morph_package exists
- # if no package is found, process continues in current file
-
- ->run_step (hook)
-
- ->unmorph
- # only called if morph worked
- # ->fixup_before_unmorph if blessed to current package
-
- # exit loop if ->run_step returned true (page printed)
-
- } end of foreach step
-
- ->post_loop
- # navigation stops if true
-
- ->default_step
- ->insert_path (puts the default step into the path)
- ->nav_loop (called again recursively)
-
- } end of nav_loop
-
-For each step of the path the following methods will be run
-during the run_step hook.
-
- run_step {
- ->pre_step (hook)
- # exits nav_loop if true
-
- ->skip (hook)
- # skips this step if true (stays in nav_loop)
-
- ->prepare (hook - defaults to true)
-
- ->info_complete (hook - ran if prepare was true)
- ->ready_validate (hook)
- return false if ! ready_validate
- ->validate (hook - uses CGI::Ex::Validate to validate form info)
- ->hash_validation (hook)
- ->file_val (hook)
- ->base_dir_abs
- ->base_dir_rel
- ->name_module
- ->name_step
- ->ext_val
- returns true if validate is true or if nothing to validate
-
- ->finalize (hook - defaults to true - ran if prepare and info_complete were true)
-
- if ! ->prepare || ! ->info_complete || ! ->finalize {
- ->prepared_print
- ->hash_base (hook)
- ->hash_common (hook)
- ->hash_form (hook)
- ->hash_fill (hook)
- ->hash_swap (hook)
- ->hash_errors (hook)
- # merge form, base, common, and fill into merged fill
- # merge form, base, common, swap, and errors into merged swap
- ->print (hook - passed current step, merged swap hash, and merged fill)
- ->file_print (hook - uses base_dir_rel, name_module, name_step, ext_print)
- ->swap_template (hook - processes the file with CGI::Ex::Template)
- ->template_args (hook - passed to CGI::Ex::Template->new)
- ->fill_template (hook - fills the any forms with CGI::Ex::Fill)
- ->fill_args (hook - passed to CGI::Ex::Fill::fill)
- ->print_out (hook - print headers and the content to STDOUT)
-
- ->post_print (hook - used for anything after the print process)
-
- # return true to exit from nav_loop
- }
-
- ->post_step (hook)
- # exits nav_loop if true
-
- } end of run_step
-
-It is important to learn the function and placement of each of the
-hooks in the process flow in order to make the most of CGI::Ex::App.
-It is enough to begin by learning a few common hooks - such as
-hash_validation, hash_swap, and finalize, and then learn about other
-hooks as needs arise. Sometimes, it is enough to simply override the
-run_step hook and take care of processing the entire step yourself.
-
-Because of the hook based system, and because CGI::Ex::App uses
-sensible defaults, it is very easy to override a little or a lot which
-ends up giving the developer a lot of flexibility.
-
-Consequently, it should be possible to use CGI::Ex::App with the other
-frameworks such as CGI::Application or CGI::Prototype. For these you
-could simple let each "runmode" call the run_step hook of CGI::Ex::App
-and you will instantly get all of the common process flow for free.
-
=head1 AVAILABLE METHODS / HOOKS
CGI::Ex::App's dispatch system works on the principles of hooks (which
See the get_valid_auth method.
+=item base_dir_abs (method)
+
+Used as the absolute base directory to find template files and validation files.
+It may return a single value or an arrayref of values, or a coderef that
+returns an arrayref or coderef of values. You may pass base_dir_abs
+as a parameter in the arguments passed to the "new" method.
+
+Default value is "".
+
+For example, to pass multiple paths, you would use something
+similar to the following:
+
+ sub base_dir_abs {
+ return ['/my/path/one', '/some/other/path'];
+ }
+
+The base_dir_abs value is used along with the base_dir_rel, name_module,
+name_step, ext_print and ext_values for determining the values
+returned by the default file_print and file_val hooks. See those methods
+for further discussion.
+
+See the section on FINDING TEMPLATES for further discussion.
+
+=item base_dir_rel (method)
+
+Added as a relative base directory to content under the base_dir_abs directory.
+
+Default value is "".
+
+The base_dir_abs method is used as top level where template includes may
+pull from, while the base_dir_rel is directory relative to the base_dir_abs
+where the content files will be stored.
+
+A value for base_dir_rel may passed as a parameter in the arguments passed
+to the new method.
+
+See the base_dir_abs method for more discussion.
+
+See the section on FINDING TEMPLATES for further discussion.
+
=item cleanup_user (method)
-Installed as a hook during get_valid_auth. Allows for cleaning
+Used as a hook during get_valid_auth. Allows for cleaning
up the username. See the get_valid_auth method.
- sub cleanup_user {
- my ($self, $user) = @_;
- return lc $user;
- }
+ sub cleanup_user {
+ my ($self, $user) = @_;
+ return lc $user;
+ }
+
+=item clear_app (method)
+
+If the same CGI::Ex::App based object is used to run multiple
+navigate sessions, the clear_app method should be called which
+will attempt to clear as much session information as it can.
+The following items will be cleared:
+
+ cgix
+ vob
+ form
+ cookies
+ stash
+ path
+ path_i
+ history
+ __morph_lineage_start_index
+ __morph_lineage
+ hash_errors
+ hash_fill
+ hash_swap
+ hash_common
=item current_step (method)
method is called, the step is added to the path, and nav_loop calls
itself recursively.
+=item destroy (method)
+
+Called at the end of navigate after all other actions have run. Can
+be used for undoing things done in the ->init method called during
+the ->new method.
+
=item dump_history (method)
Show simplified trace information of which steps were called, the
unmorphed before returning. Also - the post_navigate method will
still be called.
+=item ext_print (method)
+
+Added as suffix to "name_step" during the default file_print hook.
+
+Default value is 'html'.
+
+For example, if name_step returns "foo" and ext_print returns "html"
+then the file "foo.html" will be searched for.
+
+See the section on FINDING TEMPLATES for further discussion.
+
+=item ext_val (method)
+
+Added as suffix to "name_step" during the default file_val hook.
+
+Default value is 'val'.
+
+For example, if name_step returns "foo" and ext_val returns "val"
+then the file "foo.val" will be searched for.
+
+See the section on FINDING TEMPLATES for further discussion.
+
=item first_step (method)
Returns the first step of the path. Note that first_step may not be the same
Returns a filename containing the validation. Performs the same
as file_print, but uses ext_val to get the extension, and it adds
base_dir_abs onto the returned value (file_print is relative to
-base_dir_abs, while file_val is fully qualified with base_dir_abs)
+base_dir_abs, while file_val is fully qualified with base_dir_abs).
+If base_dir_abs returns an arrayref of paths, then each path is
+checked for the existence of the file.
The file should be readable by CGI::Ex::Validate::get_validation.
See the file_print method for more information.
+See the section on FINDING TEMPLATES for further discussion.
+
=item name_step (hook)
Return the step (appended to name_module) that should used when
looking up the file in file_print and file_val lookups. Defaults to
the current step.
+See the section on FINDING TEMPLATES for further discussion.
+
=item nav_loop (method)
This is the main loop runner. It figures out the current path
my $app = MyApp->new({name_module => 'my_app'});
-=item next_step (method)
+=item next_step (hook and method)
Returns the next step in the path. If there is no next step, it
returns the default_step.
+It can be used as a method to return the next step in the path
+to pass to a method such as ->jump.
+
+It is also used as a hook by the refine_path hook. If there is no
+more steps, it will call the next_step hook to try and find a step to
+append to the path.
+
=item path (method)
Return an arrayref (modifiable) of the steps in the path. For each
default_step will be run. This is what allows for us to default
to the "main" step for many applications.
+=item path_info_map (hook)
+
+Used to map path_info parts to form variables. Similar to the
+path_info_map_base method. See the path_info_map_base method
+for a discussion of how to use this hook.
+
+=item path_info_map_base (method)
+
+Called during the default path method. It is used to custom map portions
+of $ENV{'PATH_INFO'} to form values. If should return an arrayref of
+arrayrefs where each child arrayref contains a regex qr with match parens
+as the first element of the array. Subsequent elements of the array are
+the key names to store the corresponding matched value from the regex under.
+The outer arrayref is iterated until it one of child arrayrefs matches
+against $ENV{'PATH_INFO'}. The matched values are only added to the form if
+there is not already a defined value for that key in the form.
+
+The default value returned by this method looks something like the following:
+
+ sub path_info_map_base {
+ return [[qr{^/(\w+)}, $self->step_key]];
+ }
+
+This example would map the following PATH_INFO string as follows:
+
+ /my_step
+
+ # $self->form->{'step'} now equals "my_step"
+
+The following is another example:
+
+ sub path_info_map_base {
+ return [
+ [qr{^/([^/]+)/(\w+)}, 'username', $self->step_key],
+ [qr{^/(\w+)}, $self->step_key],
+ ];
+ }
+
+ # the PATH_INFO /my_step
+ # still results in
+ # $self->form->{'step'} now equals "my_step"
+
+ # but with the PATH_INFO /my_user/my_step
+ # $self->form->{'step'} now equals "my_step"
+ # and $self->form->{'username'} equals "my_user"
+
+In most cases there is not a need to override the path_info_map_base
+method, but rather override the path_info_map hook for a particular step.
+When the step is being run, just before the run_step hook is called, the
+path_info_map hook is called. The path_info_map hook is similar to
+the path_info_map_base method, but is used to allow step level manipulation
+of form based on elements in the $ENV{'PATH_INFO'}.
+
+ sub my_step_path_info_map {
+ return [[qr{^/my_step/(\w+)$}, 'username']];
+ }
+
+ # the PATH_INFO /my_step/my_user
+ # results in
+ # $self->form->{'step'} equal to "my_step" because of default path_info_map_base
+ # and $self->form->{'username'} equals "my_user" because of my_step_path_info_map
+
+The section on mapping URIs to steps has additional examples.
+
=item post_loop (method)
Ran after all of the steps in the loop have been processed (if
Changing the behavior of ready_validate can help in making wizard type
applications.
+=item refine_path (hook)
+
+Called at the end of nav_loop. Passed a single value indicating
+if there are currently more steps in the path.
+
+The default implementation returns if there are still more steps
+in the path. Otherwise, it calls the next_step hook and appends
+it to the path with the append_path method, and then calls
+the set_ready_validate hook and passes it 0.
+
+This allows you to simply put
+
+ sub edit_next_step { '_edit_success' }
+
+In your code and it will automatically do the right thing and
+go to the _edit_success step.
+
=item recurse_limit (method)
Default 15. Maximum number of times to allow nav_loop to call itself.
This method is not normally used.
-=item set_ready_validate (method)
+=item set_ready_validate (hook and method)
-Sets that the validation is ready to validate. Should set the value
+Sets that the validation is ready (or not) to validate. Should set the value
checked by the hook ready_validate. The following would complement the
processing flag above:
sub set_ready_validate {
my $self = shift;
- if (shift) {
+ my ($step, $is_ready) = (@_ == 2) ? @_ : (undef, shift);
+ if ($is_ready) {
$self->form->{'processing'} = 1;
} else {
delete $self->form->{'processing'};
}
+ return $is_ready;
}
Note that for this example the form key "processing" was deleted. This
is so that the call to fill in any html forms won't swap in a value of
zero for form elements named "processing."
+Also note that this method may be called as a hook as in
+
+ $self->run_hook('set_ready_validate', $step, 0)
+ # OR
+ $self->set_ready_validate($step, 0);
+
+Or it can take a single argument and should set the ready status
+regardless of the step as in:
+
+ $self->set_ready_validate(0);
+
=item skip (hook)
Ran at the beginning of the loop before prepare, info_complete, and
Arguments are the template and the swap hashref. The template can be either a
scalar reference to the actual content, or the filename of the content. If the
-filename is specified - it should be relative to base_dir_abs.
+filename is specified - it should be relative to base_dir_abs (which will be
+used to initialize INCLUDE_PATH by default).
+
+The default method will create a template object by calling the template_args hook
+and passing the returned hashref to the template_obj method. The default template_obj method
+returns a CGI::Ex::Template object, but could easily be swapped to use a Template::Toolkit
+based object. If a non-Template::Toolkit compatible object is to be used, then
+the swap_template hook can be overridden to use another templating engine.
+
+For example to use the HTML::Template engine you could override the swap_template
+method as follows:
+
+ use HTML::Template;
+
+ sub swap_template {
+ my ($self, $step, $file, $swap) = @_;
+
+ my $type = UNIVERSAL::isa($file, 'SCALAR') ? 'scalarref'
+ : UNIVERSAL::isa($file, 'ARRAY') ? 'arrayref'
+ : ref($file) ? 'filehandle'
+ : 'filename';
+
+ my $t = HTML::Template->new(source => $file,
+ type => $type,
+ path => $self->base_dir_abs,
+ die_on_bad_params => 0,
+ );
+
+ $t->param($swap);
+
+ return $t->output;
+ }
=item template_args (hook)
Returns a hashref of args that will be passed to the "new" method of CGI::Ex::Template.
-By default this hashref contains INCLUDE_PATH which is set equal to base_dir_abs.
-It can be augmented with any arguments that CGI::Ex::Template would understand.
-
- sub template_args {
- return {
- INCLUDE_PATH => '/my/own/include/path',
- WRAPPER => 'wrappers/main_wrapper.html',
- };
- }
+The method is normally called from the swap_template hook. The swap_template hook
+will add a value for INCLUDE_PATH which is set equal to base_dir_abs, if the INCLUDE_PATH
+value is not already set.
+
+The returned hashref can contain any arguments that CGI::Ex::Template would understand.
+
+ sub template_args {
+ return {
+ PRE_CHOMP => 1,
+ WRAPPER => 'wrappers/main_wrapper.html',
+ };
+ }
+
+=item template_obj (method)
+
+Called from swap_template. It is passed the result of template_args that have
+had a default INCLUDE_PATH added. The default implementation uses CGI::Ex::Template
+but can easily be changed to use Template::Toolkit by using code similar to the following:
+
+ use Template;
+
+ sub template_obj {
+ my ($self, $args) = @_;
+ return Template->new($args);
+ }
=item unmorph (method)
=item validate (hook)
-Runs validation on the information posted in $self->form. Uses
-CGI::Ex::Validate for the default validation. Calls the hook
-hash_validation to load validation information. Should return true if
-the form passed validation and false otherwise. Errors are stored as
-a hash in $self->{hash_errors} via method add_errors and can be
-checked for at a later time with method has_errors (if the default
-validate was used).
+Passed the form from $self->form. Runs validation on the information
+contained in the passed form. Uses CGI::Ex::Validate for the default
+validation. Calls the hook hash_validation to load validation hashref
+(an empty hash means to pass validation). Should return true if the
+form passed validation and false otherwise. Errors are stored as a
+hash in $self->{hash_errors} via method add_errors and can be checked
+for at a later time with method has_errors (if the default validate
+was used).
-There are many ways and types to validate the data. Please see the L<CGI::Ex::Validate>
-module.
+There are many ways and types to validate the data. Please see the
+L<CGI::Ex::Validate> module.
Upon success, it will look through all of the items which were
validated, if any of them contain the keys append_path, insert_path,
=back
-=head1 OTHER APPLICATION MODULES
+=head1 HOW DO I SET COOKIES, REDIRECT, ETC
+
+Often in your program you will want to set cookies or bounce to a differnt URL.
+This can be done using either the builtin CGI::Ex object or the built in
+CGI object. It is suggested that you only use the CGI::Ex methods as it will
+automatically send headers and method calls under cgi, mod_perl1, or mod_perl2.
+The following shows how to do basic items using the CGI::Ex object returned by
+the ->cgix method.
+
+=over 4
+
+=item printing content-type headers
+
+ ### CGI::Ex::App prints headers for you,
+ ### but if you are printing custom types, you can send your own
+ $self->cgix->print_content_type;
+ # SAME AS
+ # $self->cgix->print_content_type('text/html');
+
+=item setting a cookie
+
+ $self->cgix->set_cookie({
+ -name => "my_key",
+ -value => 'Some Value',
+ -expires => '1y',
+ -path => '/',
+ });
+
+=item redirecting to another URL
+
+ $self->cgix->location_bounce("http://somewhereelse.com");
+ $self->exit_nav_loop; # normally should do this to long jump out of navigation
+
+=item making a QUERY_STRING
+
+ my $data = {foo => "bar", one => "two or three"};
+ my $query = $self->cgix->make_form($data);
+ # $query now equals "foo=bar&one=two%20or%20three"
+
+=item getting form parameters
+
+ my $form = $self->form;
+
+In this example $form would now contain a hashref of all POST and GET parameters
+passed to the server. The form method calls $self->cgix->get_form
+which in turn uses CGI->param to parse values. Fields with multiple passed
+values will be in the form of an arrayref.
+
+=item getting cookies
+
+ my $cookies = $self->cookies;
+
+In this example $cookies would be a hashref of all passed in cookies. The
+cookies method calls $self->cgix->get_cookies which in turn uses CGI->cookie
+to parse values.
+
+=back
+
+See the CGI::Ex and CGI documentation for more information.
+
+=head1 COMPARISON TO OTHER APPLICATION MODULES
The concepts used in CGI::Ex::App are not novel or unique. However, they
are all commonly used and very useful. All application builders were
built because somebody observed that there are common design patterns
in CGI building. CGI::Ex::App differs in that it has found more common design
-patterns of CGI's than some and tries to get in the way less than others.
+patterns of CGI's than other application builders and tries to get in the way
+less than others.
CGI::Ex::App is intended to be sub classed, and sub sub classed, and each step
can choose to be sub classed or not. CGI::Ex::App tries to remain simple
while still providing "more than one way to do it." It also tries to avoid
making any sub classes have to call ->SUPER:: (although that is fine too).
+And if what you are doing on a particular is far too complicated or custom for
+what CGI::Ex::App provides, CGI::Ex::App makes it trivial to override all behavior.
+
There are certainly other modules for building CGI applications. The
following is a short list of other modules and how CGI::Ex::App is
different.
which is only a dispatch.
* Support for easily jumping around in navigation steps.
* Support for storing some steps in another package.
+ * Integrated authentication
+ * Integrated form filling
+ * Integrated PATH_INFO mapping
CGI::Ex::App and CGI::Application are similar in that they take care
of handling headers and they allow for calling other "runmodes" from
system (CGI::Ex::App uses CGI::Ex::Template which is TT compatible).
CGI::Ex::App is differrent in that it:
- * Offers integrated data validation.
- CGI::Application has had custom addons created that
- add some of this functionality. CGI::Ex::App has the benefit
- that once validation is created,
* Offers more hooks into the various phases of each step.
* Support for easily jumping around in navigation steps.
* Support for storing only some steps in another package.
+ * Integrated data validation
+ * Integrated authentication
+ * Integrated form filling
+ * Integrated PATH_INFO mapping
=back
=head1 THANKS
+The following corporation and individuals contributed in some part to
+the original versions.
+
Bizhosting.com - giving a problem that fit basic design patterns.
Earl Cahill - pushing the idea of more generic frameworks.
Paul Seamons <paul at seamons dot com>
+=head1 LICENSE
+
+This module may be distributed under the same terms as Perl itself.
+
=cut
projects / chaz / p5-CGI-Ex / blobdiff