Michele Liberi software

versione 1.03, 1 settembre 2022

Michele Liberi mail: mliberi@gmail.com cell: 3485211456

• Presentazione
• Programmi scritti in linguaggio C
  • espressioni regolari
  • servizi TCP V4
  • accesso a servizi TCP V4
  • applicazioni WEB
    • sessioni e autenticazione
    • woha, potente archiviatore con interfaccia WEB
      • user's guide
      • administrator's guide
    • shz, gestione files e directories
    • upload, invio di files al sito web
  • nuovi comandi
  • comandi UNIX potenziati
  • crittografia
  • X clients
  • componenti CGI
• Shell scripts
• Siti WEB
• Applicazioni Android
• Installazione
• Licenza d'uso

administrator's guide

administrator's guide

Class management menu is available only for class owner and for class administrators, if any. It contains the following functions:

• classes
  • new class
  • copy class
  • delete class
• types
  • new type
  • edit type
• attributes
  • new attribute
  • edit attribute
  • move after
  • move before
• methods
  • new method
  • edit method
• settings
  • ACL
  • parameters
  • set home class

A class is a row container, it has types, attributes, methods and parameters.

A row is a data container, it contains a value for each class attribute.

A class may have subclasses, a subclass inherits types, attributes, methods and parameters from parent class.

Create a new subclass of current class. The newly created subclass inherits types, attributes, methods, and parameters from parent class.

Create a new subclass of current class, and also copy types, attributes and methods from another class. This way you can set up a class with multiple inheritance.

Delete current class. A class can be deleted only if empty. A class can't be deleted if it has subclasses and/or contains rows.

A class type has a name and contains a list of strings.

It is useful to define which value an attribute with data type oneof or manyof is allowed to get.

Create a new type in the current class.

View, modify or delete a type.

An attribute is a data container, all together attributes compose a row.

An attribute has a name, a data type and some other markers described in detail below.

Create a new attribute in current class. When creating an attribute you must provide the following markers:

name

the attribute name

data type

specify what kind of value the attribute is allowed to contain. Valid data types are:

string

any sequence of characters

number

a valid string representation of a number

boolean

'true' or 'false'

rating

an integer number from zero up to a max, graphically represented with stars

date

a valid timestamp in the specified format

oneof

a single string taken from a given class type

manyof

a set of strings taken from a given class type

textarea

a text allowed to contain multiple lines

fileset

a compound field: a filename, a file content, and a searchable index automatically created at insert/update time

image

a compound field: a filename and an image, graphically represented as a picture

created_ts

a self maintained field, auto filled with timestamp of row creation

lastupdated_ts

a self maintained field, auto filled with timestamp of row last update

username_owner

a self maintained field, auto filled with the username of row owner, that is who created the row

key field

each row has a key, composed by concatenating the values of all key fields;

the key is forced to be unique, in other words two rows with the same key are not allowed to coexist in the same class;

row key can be used to efficiently retrieve it at search or update time.

required

a required attribute can't be empty, it must contain a not null value.

hide

an attribute with hide=true will be hidden in main window. You can view it by opening the view window or by forcing it to be shown.

revision

woha is able to keep multiple revisions for the same row. You can see history of changes in view window. A new revision is automatically created whenever the value of an attribute with revision=true changes.

insert only

an insert only attribute can't be updated.

unique

a class can't contain two rows with an attribute marked as unique having the same value.

auto total

if the class contains at least one attribute with auto total=true, woha will add an extra row in the main window displaying the sum of values.

auto calc

an attribute marked as auto calc=true can't be entered by user at insert time or update time. It will be calculated by class methods just after insert or update.

idx

marking an attribute with idx=true tells woha to build and maintain an index.

hint

a short help message to guide the user while filling the input form.

format

format is a REE: attribute value is acceptable only if matches it. An empty format is meaningless.

Open a new window showing all attributes. Click on a row to get a attribute details window in order to change some marker, or to delete the attribute.

Change the sequence of attributes, that is the order attributes get displayed in all views. To move forward an attribute: select it, select the attribute placed just before the target new position, choose move after menu entry.

Change the sequence of attributes, that is the order attributes get displayed in all views. To move backward an attribute: select it, select the attribute placed just after the target new position, choose move before menu entry.

Methods are programs, the logic acting on data.

Woha is designed to create and manage methods as bash scripts, but there is no limitation about the language used to write them.

The main distinction about methods is between automatic and manual: automatic methods run when an event occur, manual methods run when called by user.

When creating a method you must provide:

name

the method name

type

specify the behaviour of this method. Valid method types are:

row read

manual: can run only if user has read permission on row

row read/write

manual: can run only if user has read and write permissions on row

table read

manual: can run only if user has read permission on class

table read/write

manual: can run only if user has read and write permissions on class

class owner

manual: can run only if user is class owner or administrator

before insert

automatic: called just before inserting a new row in the class

operation can occur only if return code is zero, otherwise it is cancelled

after insert

automatic: called just after inserting a new row in the class

usually it computes and sets all auto calc attribute values

before update

automatic: called just before updating a row

operation can occur only if return code is zero, otherwise it is cancelled

after update

automatic: called just after updating a row

usually it computes and sets all auto calc attribute values

before delete

automatic: called just before deleting a row

operation can occur only if return code is zero, otherwise it is cancelled

after delete

automatic: called just after deleting a row

post download

automatic: called just after user downloaded a set of rows

insert

automatic: customized insert form, overrides standard form

edit

automatic: customized edit form, overrides standard form

sort order

a string: specify order for building user's menu (manual methods), or order used to run them (automatic methods)

Call this function to view or modify an existing method.

ACL stands for Access Control List, it is a standard structure managed by the operating system to manage access permissions.

Each class, row and method can have its own ACL.

Each class has a set of parameters. Subclasses inherit parameters from parent class.

If prefixed with a ! (bang) character, a flag is false

Call this function to view and eventually change current class parameters:

default filters

filters set in the default view. Each filter is in the form =name=ree, where name is the attribute name, and ree is an expression of regular expressions.

default sorting keys

sorting keys in the default view. Four forms are legal:

1. ^name: sort by attribute with given name, from lower to higher
2. vname: sort by attribute with given name, from higher to lower
3. ^id: sort by attribute with given ID, from lower to higher
4. vid: sort by attribute with given ID, from higher to lower

show_rowid flag

If true, show row id (a unique identifier automatically assigned by woha at insert time) in the main window. The row id is always visible in view window.

encrypt flag

If true, all attribute values are stored in the database in encrypted form.

index flag

If true, woha maintains an index of data contained in the class. It will speed up accessing data stored in class with many rows, but has two disadvantages: encryption is not effective, access permissions are not effective.

max rows number

When you enter a class a main window will be shown only if the number of rows going to be displayed is less than this number, otherwise user is broght directly to search window. Default value is 128.

umask

Umask is a hexadecimal number, with the same meaning as in UNIX systems. It will be used at insert time to set default row access permissions.

class administrators

By default each class is managed by its owner. Class owner can allow or disallow users to manage his class.

A=username	set named user as class administrator
A=	empty list of class administrators
A+username	add named user to the list of class administrators
A-username	subtract named user from the list of class administrators

Each database has a home class. When you access a DB the current class is the home class.

By calling this function database administrator sets the current class as the home class.