Entity-Relationship diagrams is a very common type graphics that is usually designed to document systems and help people understand how they are structured providing a visual representation of its elements and how they are related.
Entity-Relationship diagrams are often use to represent related classes of objects or database tables and the foreign keys that establish the relationships between them.
This class provides a means to draw Entity-Relationship diagrams based on details that define the entities and the relationship connections between them.
The class can simplify the generation of the diagramas by automatically creating a layout for the entities and generates images that can be used to enrich the documentation of the projects on which the represent entities are used.
This class is meant to generate images that present entity-relationship diagrams.
The entities are represented by rectangles with a text that represents its name. The relationships are represented by lines that connect the relationships rectangles.
The class models entity objects to which may be associated relationships to other entity objects.
The class can draw the entity rectangles in given coordinates of an images created with the GD library.
The relationship lines are drawn in coordinates determined automatically by the class from the respective entity coordinates. The class can also draw labels that are associated to each relationship.
The image can be outputted in any format supported by the GD library.
The supplied example generates clickable image maps that are linked to URLs associated to each entry. You need the TrueType font named tahoma.ttf in the fuentes directory. The example stores the generated image in the tmp sub-directory of the script directory.