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Development Team/Almanac/sugar.datastore.datastore (view source)
Revision as of 21:32, 23 February 2010
, 21:32, 23 February 2010moved Walter is a wanker 12/Almanac/sugar.datastore.datastore to Development Team/Almanac/sugar.datastore.datastore over redirect: revert
{{Sugar Almanac}}
{{Almanac}}
{{Sugar Almanac TOC}}
{{Almanac TOC}}
= High Level Functionality of the Datastore =
= High Level Functionality of the Datastore =
=== How do I provide a query to the datastore.find() method so that I can find datastore objects with a particular property? ===
=== How do I provide a query to the datastore.find() method so that I can find datastore objects with a particular property? ===
'''IMPORTANT''' Do not rely on datastore.find() method in all cases, its behaviour could be changed in future releases;<br>there is only on thing for sure: to treat jobjects that were created within activity use:<br>datastore.find({'activity_id': <activity-id-of(and only of)-current-activity>, ...})
The datastore package includes a find() helper function that allows you to find things in the datastore. Belows is a very simple example use of find where I simply search for journal entries that have a title of 'file1.txt'. I think print out the title and file path for each retreived entry.
The datastore package includes a find() helper function that allows you to find things in the datastore. Belows is a very simple example use of find where I simply search for journal entries that have a title of 'file1.txt'. I think print out the title and file path for each retreived entry.
print "Number of Objects: " + str(num_objects)
print "Number of Objects: " + str(num_objects)
for i in xrange (0, num_objects, 1):
for i in xrange (num_objects):
print "File Path: " + ds_objects[i].get_file_path()
print "File Path: " + ds_objects[i].get_file_path()
print "Title: " + ds_objects[i].metadata['title']
print "Title: " + ds_objects[i].metadata['title']
#loop through and delete each datastore object found.
#loop through and delete each datastore object found.
for i in xrange (0, num_objects, 1):
for i in xrange (num_objects):
print 'DELETING ' + ds_objects[i].metadata['title'] + '...'
print 'DELETING ' + ds_objects[i].metadata['title'] + '...'
ds_objects[i].destroy()
ds_objects[i].destroy()
#loop through list of values and print them out.
#loop through list of values and print them out.
for i in xrange(0, len(unique_val_array), 1):
for x in unique_val_array:
print str(unique_val_array[i])
print x
</pre>
</pre>
print '------------------------MOUNTS--------------------------------'
print '------------------------MOUNTS--------------------------------'
ds_mounts = datastore.mounts()
ds_mounts = datastore.mounts()
for i in xrange(0, len(ds_mounts), 1):
for x in ds_mounts:
print '---------MOUNT---------'
print '---------MOUNT---------'
print 'title: '+ ds_mounts[i]['title']
print 'title: '+ x['title']
print 'uri: '+ ds_mounts[i]['uri']
print 'uri: '+ x['uri']
print 'id: ' + ds_mounts[i]['id']
print 'id: ' + x['id']
</pre>
</pre>
=== How do I access the metadata entries for a datastore object? ===
=== How do I access the metadata entries for a datastore object? ===
Every DSObject created by datastore.create() has a metadata property. This property refers to a [[#Class: DSMetadata | DSMetadata object]], which contains the metadata for your datastore object. The code below shows how to read metadata values by referring to the metadata property of a DSObject. metadata is a Python dictionary object.
Every DSObject created by datastore.create() has a metadata property. This property refers to a [[Low-level_Activity_API#Meta_Data|DS Object]], which contains the metadata for your datastore object. The code below shows how to read metadata values by referring to the metadata property of a DSObject. metadata is a Python dictionary object.
<pre>
<pre>
from sugar.datastore import datastore
from sugar.datastore import datastore
...
...
#my_dsobject is of type datastore.DSObject
#my_dsobject is of type datastore.DSObject
#object_id is a datastore object (returned from the datastore Chooser
#object_id is a datastore object (e.g., returned from the datastore Chooser)
my_dsobject = datastore.get(object_id)
my_dsobject = datastore.get(object_id)
print my_dsobject.metadata['description']
print my_dsobject.metadata['description']
#other standard objects in the metadata dictionary include 'tags', 'title', 'mimetypes', ...
</pre>
This code snippet shows how to create a pixbuf from the preview entry in the datastore:
<pre>
from sugar.datastore import datastore
...
#my_dsobject is of type datastore.DSObject
#object_id is a datastore object
my_dsobject = datastore.get(object_id)
pixbufloader = gtk.gdk.pixbuf_loader_new_with_mime_type('image/png')
#Access the 'preview' property
#Note that the preview image is 300x225
pixbufloader.write(dsobject.metadata['preview'])
pixbufloader.close()
pixbuf = pixbufloader.get_pixbuf()
</pre>
</pre>