Differences

This shows you the differences between two versions of the page.

--- dev-guide:embedded-file-object [2025/01/08 16:34] – created gaetan
+++ dev-guide:embedded-file-object [2025/01/08 19:11] (current) – gaetan
@@ Line 1: / Line 1: @@
-====== ESO ARE THE BEST ======
+====== Custom object persistence ======
+GroIMP require Nodes, Node's attributes, and SCOs to be manageable by the persistence manager, to process the save/ load/ query operations.
+GroIMP define its own [[:groimp-platform:persistence|persistence management]]. To be managed by the GroIMP persistence management, an object need to implements either [[https://javadoc.grogra.de/graph/de/grogra/persistence/PersistenceCapable.html|PersistenceCapable]] (GroIMP interface), or [[https://docs.oracle.com/javase/8/docs/api/java/io/Serializable.html|Serializable]] (java interface).
+Usually the persistence is handled in memory (except when the project is saved), but GroIMP provides a way to integrate it with file persistence (the object is written/loaded from the file). This rely on EmbeddedSharedObject and EmbeddedFileObject.
+===== Embedded objects =====
+In GroIMP embedded objects are objects whose persistence is pushed in a file.
+EmbeddedSharedObject (ESO) is a class, thus the object needs to extends it.
+The ESO create on the fly and manage an EmbeddedFileObject (EFO).
+The object that extends ESO need to implements the following methods:
+  * ''public MimeType getMimeType()'': to provide the mimetype to use when writing and loading the object (see GroIMP [[:groimp-platform:input-and-output-in-groimp:mimetype|mimetype]]).
+  * ''public String getExtension()'': to provide the file extension (can be an empty string. File extensions are used to make it easier read files but are usually not required).
+  * ''public String getResourceDirectoryName()'': Name of the directory in which the file will be stored when the project is saved.
+  * ''public String getObjectType()'': java name of the object type (e.g. MyObject.class.getName()).
+  * ''public boolean hasContent()'': custom way to check if the object actually needs to be disposed. Can be set to true if it is always the case.
+Check [[:tutorials:create-parameternode-eso|this tutorial]] for an example.