Make it possible to delete plans

Each plan will have now delete_key (random, 50 character string), which
can be used with url like http://.../d/plan-id/delete-key
to delete it.

The delete key is shown once just after plan creation

lib/Explain.pm

@@ -32,6 +32,9 @@ sub startup {
     # route: 'show'
     $routes->route( '/s/:id' )->to( 'controller#show', id => '' )->name( 'show' );
 
+    # route: 'delete'
+    $routes->route( '/d/:id/:key' )->to( 'controller#delete', id => '', key => '' )->name( 'delete' );
+
     # route: 'history'
     $routes->route( '/history/:date' )->to( 'controller#history', date => '' )->name( 'history' );
 

lib/Explain/Controller.pm

@@ -61,12 +61,36 @@ sub index {
     }
 
     # save to database
-    my $id = $self->database->save_with_random_name( $title, $plan, $is_public, $is_anon, );
+    my ( $id, $delete_key ) = $self->database->save_with_random_name( $title, $plan, $is_public, $is_anon, );
 
     # redirect to /show/:id
+    $self->flash( delete_key => $delete_key );
     return $self->redirect_to( 'show', id => $id );
 }
 
+sub delete {
+    my $self = shift;
+
+    # value of "/:id" param
+    my $id = defined $self->stash->{ id } ? $self->stash->{ id } : '';
+
+    # value of "/:key" param
+    my $key = defined $self->stash->{ key } ? $self->stash->{ key } : '';
+
+    # missing or invalid
+    return $self->redirect_to( 'new-explain' ) unless $id =~ m{\A[a-zA-Z0-9]+\z};
+    return $self->redirect_to( 'new-explain' ) unless $key =~ m{\A[a-zA-Z0-9]+\z};
+
+    # delete plan in database
+    my $delete_worked = $self->database->delete_plan( $id, $key );
+
+    # not found in database
+    return $self->redirect_to( 'new-explain', status => 404 ) unless $delete_worked;
+
+    $self->flash( message => sprintf( 'Plan %s deleted.', $id ) );
+    return $self->redirect_to( 'new-explain' );
+}
+
 sub show {
     my $self = shift;
 

lib/Explain/Plugin/Database.pm

@@ -34,12 +34,14 @@ sub register {
     }
 
     # database (DBI) connection arguments
-    $self->connection_args( [
+    $self->connection_args(
+        [
             $config->{ dsn },
             $config->{ username },
             $config->{ password },
             $config->{ options } || {}
-    ] );
+        ]
+    );
 
     # log debug message
     $app->log->debug( 'Database connection args: ' . $app->dumper( $self->connection_args ) );
@@ -66,45 +68,48 @@ sub register {
 }
 
 sub save_with_random_name {
-    my ( $self, $title, $content, $is_public, $is_anon ) = @_;
+    my $self = shift;
+    my ( $title, $content, $is_public, $is_anon ) = @_;
 
-    # create statement handler
-    my $sth = $self->dbh->prepare( 'SELECT register_plan(?, ?, ?, ?)' );
+    my @row = $self->dbh->selectrow_array(
+        'SELECT id, delete_key FROM register_plan(?, ?, ?, ?)',
+        undef,
+        $title, $content, $is_public, $is_anon,
+    );
 
-    # execute
-    $sth->execute( $title, $content, $is_public, $is_anon );
-
-    # register_plan returns plan id
-    my @row = $sth->fetchrow_array;
-
-    # finish
-    $sth->finish;
-
-    # return plan id
-    return $row[ 0 ];
+    # return id and delete_key
+    return @row;
 }
 
-# @depesz
-#  - why you don't use selectrow_array (or similar)?
 sub get_plan {
-    my ( $self, $plan_id ) = @_;
+    my $self = shift;
+    my ( $plan_id ) = @_;
 
-    # create statement handler
-    my $sth = $self->dbh->prepare( 'SELECT plan, title FROM plans WHERE id = ?' );
-
-    # execute
-    $sth->execute( $plan_id );
-
-    # fetch row
-    my @row = $sth->fetchrow_array;
-
-    # finish
-    $sth->finish;
+    my @row = $self->dbh->selectrow_array(
+        'SELECT plan, title FROM plans WHERE id = ? AND NOT is_deleted',
+        undef,
+        $plan_id,
+    );
 
     # return plan
     return @row;
 }
 
+sub delete_plan {
+    my $self = shift;
+    my ( $plan_id, $delete_key ) = @_;
+    my @row = $self->dbh->selectrow_array(
+        'UPDATE plans SET plan = ?, title = ?, is_deleted = true, delete_key = NULL WHERE id = ? and delete_key = ? RETURNING 1',
+        undef,
+        '',
+        'This plan has been deleted.',
+        $plan_id,
+        $delete_key
+    );
+    return 1 if $row[ 0 ];
+    return;
+}
+
 sub get_public_list {
     my $self = shift;
 
@@ -158,6 +163,7 @@ sub get_public_list_paged {
           WHERE is_public
             AND entered_on > ?::date
             AND entered_on < ?::date
+            AND NOT is_deleted
        ORDER BY entered_on
            DESC',
         { Slice => {} },

public/css/style.css

@@ -367,6 +367,10 @@ div.message p.message { font-weight: bold; font-size: 2em; color: #ff0; padding:
 div.message p.hint { color: #ff0; padding: 0; margin: 0; }
 div.message p.hint a { color: #ff0; }
 div.message p.hint a:hover { color: #ff0; }
+div.message p.message a,
+div.message p.message a:visited {color:#ff0;border: none;}
+div.messageNice { border: 2px solid #0f0; background: #060; }
+
 div.plea { text-align: center; color: #666; padding-top: 1em; }
 
 .result-stats h1 {color:#123}

sql/patch-001.sql

@@ -0,0 +1,37 @@
+-- Patch that adds ability to delete plan
+
+alter table plans add column delete_key text;
+alter table plans add column is_deleted bool NOT NULL DEFAULT false;
+
+CREATE type register_plan_return as (
+    id TEXT,
+    delete_key TEXT
+);
+
+DROP FUNCTION register_plan(in_plan text, in_is_public boolean);
+DROP FUNCTION register_plan(in_plan text, in_is_public boolean, in_is_anonymized boolean);
+
+DROP FUNCTION register_plan(in_title text, in_plan text, in_is_public boolean, in_is_anonymized boolean);
+CREATE FUNCTION register_plan(in_title text, in_plan text, in_is_public boolean, in_is_anonymized boolean) RETURNS register_plan_return
+    LANGUAGE plpgsql
+    AS $$
+DECLARE
+    use_hash_length int4 := 2;
+    reply register_plan_return;
+BEGIN
+    reply.delete_key := get_random_string( 50 );
+    LOOP
+        reply.id := get_random_string(use_hash_length);
+        BEGIN
+            INSERT INTO plans (id, title, plan, is_public, entered_on, is_anonymized, delete_key) values (reply.id, in_title, in_plan, in_is_public, now(), in_is_anonymized, reply.delete_key );
+            RETURN reply;
+        EXCEPTION WHEN unique_violation THEN
+                -- do nothing
+        END;
+        use_hash_length := use_hash_length + 1;
+        IF use_hash_length >= 30 THEN
+            raise exception 'Random string of length == 30 requested. something''s wrong.';
+        END IF;
+    END LOOP;
+END;
+$$;

templates/controller/index.html.ep

@@ -12,6 +12,12 @@
     </div>
 % }
 
+% if ( flash( 'message' ) ) {
+    <div class="message">
+    <p class="message"><%= flash( 'message' ) =%></p>
+    </div>
+% }
+
 <form id="new-explain" method="post" action="<%= url_for 'current' %>">
 
     <div class="fe fe-first fe_plan">

templates/controller/show.html.ep

@@ -296,6 +296,13 @@
 
 <h1>Result: <%= $full_title %></h1>
 
+% if ( flash( 'delete_key' ) ) {
+    <div class="message messageNice">
+    <p class="message">To delete this plan, you can use <a href="<%= url_for( 'delete', id => $id, key => flash( 'delete_key' ) )=%>">this link</a>.</p>
+    <p class="hint">This link will not be shown any more, so you might want to bookmark it, just in case.</p>
+    </div>
+% }
+
 <div class="explain-form">
 
     <form id="explain-form" class="hidden" method="get" action="<%= url_for 'current' %>" autocomplete="off">