.. _geodatabuilder:

GeoDataBuilder
===============

| This section will guide you to use *GeoDataBuilder* GAIR to browse, create and manage (if you are a GAIR singed in user) a geo expression to combine geospatial information stored on the Geoportal itself.
| The aim of the GeoDataBuilder is to produce new layers, useful for *Case Studies* analysis.
| The *Explore GeoDataBuilder* main page can be accessed from the :guilabel:`Data` dropdown menu of the navigation bar (at the top of the page), shown in the picture below.

.. figure:: img/geodatabuilder_link.png
   :alt: Link to Explore GeoDataBuilder
   :align: center
   :name: geodatabuilder_link

   Link to Explore GeoDataBuilder

| In the *Explore GeoDataBuilder* main page you can see a list of "geo" expression previously created by GAIR users, with a title and short description.
| Each expression is related to a case study. 
| The content can be available or not, according to the user profile permission.
| Only authenticated user can create new expression.

.. figure:: img/explore_geodatabuilder_exp.png
   :alt: Explore GeoDataBuilder
   :align: center
   :name: explore_geodatabuilder_exp

   Explore GeoDataBuilder

The :guilabel:`View Expression` button of the *Explore GeoDataBuilder* opens the relative expression's page.

GeoDataBuilder - Expression
----------------------------

A *GeoDataBuilder Expression* is a geo expression, created by GAIR singed in user, that combine geospatial information stored on the Geoportal, and produce new layer, 
useful for *Case Studies* analysis.

Each geo expression has a title and a description, heplful to identify the expression itself.
The black box shows the layers names and the operators used by the expression.

.. figure:: img/view_geodatabuilder_exp.png
   :alt: GeoDataBuilder Expression
   :align: center
   :name: view_geodatabuilder_exp

   GeoDataBuilder Expression

The Thumbnail and some brief information on the layers combined in the expression are listed below the expression box. A link to the related Case Study is available on the right.

GeoDataBuilder - Create new Expression
---------------------------------------

A new GeoDataBuilder expression allows to combine geospatial information stored in the Geoportal to create a new layer, useful for *Case Studies* analysis. In fact the result, 
that expresses a combination of layers, will be selectable as input of a specific case study.

On this feature-rich page, the fields provided in the interface,highlighted with an asterisk, are mandatory.

Required fields include:
-	A title, as the name of the expression, 
-	a clear and comprehensive description (to allow other users of the GAIR to easily understand the use and context of the expression created).

.. figure:: img/create_new_geodatabuilder_exp.png
   :alt: Create new Expression
   :align: center
   :name: create_new_geodatabuilder_exp

   Create new Expression

When creating a new expression, it is also mandatory to specify the existing case study to whom associate the expression. This association can be done by selecting the Case Study from the drop-down menu. 
This means that it is necessary to create the case study first, in order to be able to associate an expression with it.

A geo expression is a orderly succession of layers (filterable with options and selectable with a click in the list displayed below) and spatial operators.
Spatial operator are selectable from the available options: :guilabel:`+`, :guilabel:`-`, :guilabel:`x`; :guilabel:`÷`.
and brackets and numeric values ​​can also be added.
If you wish to remove one of the elements you added in the black box, just select it by clicking and then press the bin icon that shows above it. 
Remember that at least one layer is required for a valid expression and the brackets can't be empty.

The :guilabel:`Save Expression` button create the expression. If the expression is not valid an error message and some useful indications are displayed and the save function are not available.