84 lines
3.4 KiB
Python
84 lines
3.4 KiB
Python
# Tree (Hierarchical) Nested Set Model (nsm)
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#
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# To use the nested set model,
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# use the following pattern
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# 1. name your parent field as "parent_node" if not have a property nsm_parent_field as your field name in the document class
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# 2. have a field called "old_parent" in your fields list - this identifies whether the parent has been changed
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# 3. call update_nsm(doc_obj) in the on_upate method
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# ------------------------------------------
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import webnotes
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# called in the on_update method
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def update_nsm(doc_obj):
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# get fields, data from the DocType
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d = doc_obj.doc
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pf, opf = 'parent_node', 'old_parent'
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if hasattr(doc_obj,'nsm_parent_field'):
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pf = doc_obj.nsm_parent_field
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if hasattr(doc_obj,'nsm_oldparent_field'):
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opf = doc_obj.nsm_oldparent_field
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p, op = d.fields[pf], d.fields.get(opf, '')
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# has parent changed (?) or parent is None (root)
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if not doc_obj.doc.lft and not doc_obj.doc.rgt:
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update_add_node(doc_obj.doc.doctype, doc_obj.doc.name, p or '', pf)
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elif op != p:
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update_remove_node(doc_obj.doc.doctype, doc_obj.doc.name)
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update_add_node(doc_obj.doc.doctype, doc_obj.doc.name, p or '', pf)
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# set old parent
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webnotes.conn.set(d, opf, p or '')
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def rebuild_tree(doctype, parent_field):
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# get all roots
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right = 1
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result = webnotes.conn.sql("SELECT name FROM `tab%s` WHERE `%s`='' or `%s` IS NULL" % (doctype, parent_field, parent_field))
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for r in result:
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right = rebuild_node(doctype, r[0], right, parent_field)
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def rebuild_node(doctype, parent, left, parent_field):
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# the right value of this node is the left value + 1
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right = left+1
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# get all children of this node
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result = webnotes.conn.sql("SELECT name FROM `tab%s` WHERE `%s`='%s'" % (doctype, parent_field, parent))
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for r in result:
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right = rebuild_node(doctype, r[0], right, parent_field)
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# we've got the left value, and now that we've processed
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# the children of this node we also know the right value
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webnotes.conn.sql('UPDATE `tab%s` SET lft=%s, rgt=%s WHERE name="%s"' % (doctype,left,right,parent))
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#return the right value of this node + 1
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return right+1
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def update_add_node(doctype, name, parent, parent_field):
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# get the last sibling of the parent
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if parent:
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right = webnotes.conn.sql("select rgt from `tab%s` where name='%s'" % (doctype, parent))[0][0]
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else: # root
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right = webnotes.conn.sql("select ifnull(max(rgt),0)+1 from `tab%s` where ifnull(`%s`,'') =''" % (doctype, parent_field))[0][0]
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right = right or 1
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# update all on the right
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webnotes.conn.sql("update `tab%s` set rgt = rgt+2 where rgt >= %s" %(doctype,right))
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webnotes.conn.sql("update `tab%s` set lft = lft+2 where lft >= %s" %(doctype,right))
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# update index of new node
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if webnotes.conn.sql("select * from `tab%s` where lft=%s or rgt=%s"% (doctype, right, right+1))
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webnotes.msgprint("Nested set error. Please send mail to support")
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raise Exception
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webnotes.conn.sql("update `tab%s` set lft=%s, rgt=%s where name='%s'" % (doctype,right,right+1,name))
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return right
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def update_remove_node(doctype, name):
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left = webnotes.conn.sql("select lft from `tab%s` where name='%s'" % (doctype,name))
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if left[0][0]:
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# reset this node
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webnotes.conn.sql("update `tab%s` set lft=0, rgt=0 where name='%s'" % (doctype,name))
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# update all on the right
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webnotes.conn.sql("update `tab%s` set rgt = rgt-2 where rgt > %s" %(doctype,left[0][0]))
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webnotes.conn.sql("update `tab%s` set lft = lft-2 where lft > %s" %(doctype,left[0][0]))
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