Sugar.datastore.datastore: Difference between revisions

From OLPC
Jump to navigation Jump to search
No edit summary
Line 1: Line 1:
{{Sugar Almanac TOC}}
{{Sugar Almanac TOC}}

= Datastore Helper Functions =

=== How do I create a new datastore object? ===
=== How do I create a new datastore object? ===
In addition to the [[Sugar.activity.activity#How_do_I_implement_a_write_file_method_for_my_activity_in_order_to_persist_my_activity_in_the_journal.3F | write_file()]] method, which allows sugar's activity code to save your activity by creating a datastore object, you can explicitly create datastore objects in your activity code using the datastore.create() method. The following code shows how a new datastore object is created and then actually written to the datastore. Other sections will discuss how this datastore object can actually be assigned to files and populated with useful metadata.
In addition to the [[Sugar.activity.activity#How_do_I_implement_a_write_file_method_for_my_activity_in_order_to_persist_my_activity_in_the_journal.3F | write_file()]] method, which allows sugar's activity code to save your activity by creating a datastore object, you can explicitly create datastore objects in your activity code using the datastore.create() helper function. This function will return an object of type DSObject. The following code shows how a new datastore object is created and then actually written to the datastore. Other sections will discuss how this datastore object can actually be assigned to files and populated with useful metadata.


<pre>
<pre>
Line 16: Line 19:
return my_dsobject
return my_dsobject
</pre>
</pre>

= Class: DSObject =

=== How do I create new metadata entries or reassign metadata for a datastore object that has been created? ===
Every DSObject created by datastore.create() has a metadata property. This property refers to a DSMetadata object, which contains the metadata for your datastore object. The code below shows how to assign metadata values by referring to the metadata property of a DSObject.
<pre>
#my_dsobject is of type datastore.DSObject
my_dsobject = datastore.create()
#Map the 'filename' property to a specific filename
my_dsobject.metadata['filename'] = 'krugman-ebooks.txt'

datastore.write(my_dsobject)
</pre>

= Class: DSMetadata =



= Notes =
= Notes =

Revision as of 21:01, 18 June 2008

Sugar Almanac for Developers

Sugar Almanac Main Page

Package: sugar

sugar.env

sugar.profile

sugar.mime

Package: sugar.activity

sugar.activity.activity

sugar.activity.registry

Package: sugar.graphics

sugar.graphics.alert

sugar.graphics.toolbutton

sugar.graphics.toolbox

Package: sugar.datastore

sugar.datastore.datastore

Logging

sugar.logger

Notes on using Python Standard Logging in Sugar

Internationalization

Internationalization in Sugar

Datastore Helper Functions

How do I create a new datastore object?

In addition to the write_file() method, which allows sugar's activity code to save your activity by creating a datastore object, you can explicitly create datastore objects in your activity code using the datastore.create() helper function. This function will return an object of type DSObject. The following code shows how a new datastore object is created and then actually written to the datastore. Other sections will discuss how this datastore object can actually be assigned to files and populated with useful metadata.

    #This method creates a datastore object that will be saved for later use by this activity. 
    def _create_ds_object(self):
        #my_dsobject is of type datastore.DSObject
        my_dsobject = datastore.create()

        # ... you can put any code to change your datastore file and metadata here ...

        #Persist this newly created datastore object in the datastore for later access. 
        datastore.write(my_dsobject)

        return my_dsobject

Class: DSObject

How do I create new metadata entries or reassign metadata for a datastore object that has been created?

Every DSObject created by datastore.create() has a metadata property. This property refers to a DSMetadata object, which contains the metadata for your datastore object. The code below shows how to assign metadata values by referring to the metadata property of a DSObject.

        #my_dsobject is of type datastore.DSObject
        my_dsobject = datastore.create()
        
        #Map the 'filename' property to a specific filename 
        my_dsobject.metadata['filename'] = 'krugman-ebooks.txt'

        datastore.write(my_dsobject)

Class: DSMetadata

Notes

<references />