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1 Interfaces |
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2 ---------- |
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3 |
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4 This is the same thing as object-oriented programming `interfaces`_. |
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5 |
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6 .. _`interfaces`: http://java.sun.com/docs/books/tutorial/java/concepts/interface.html |
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7 |
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8 Definition of an interface is quite trivial. An example from cubicweb |
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9 itself (found in cubicweb/interfaces.py): |
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10 |
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11 .. sourcecode:: python |
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12 |
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13 class ITree(Interface): |
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14 |
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15 def parent(self): |
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16 """returns the parent entity""" |
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17 |
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18 def children(self): |
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19 """returns the item's children""" |
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20 |
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21 def children_rql(self): |
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22 """returns RQL to get children""" |
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23 |
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24 def iterchildren(self): |
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25 """iterates over the item's children""" |
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26 |
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27 def is_leaf(self): |
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28 """returns true if this node as no child""" |
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29 |
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30 def is_root(self): |
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31 """returns true if this node has no parent""" |
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32 |
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33 def root(self): |
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34 """returns the root object""" |
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35 |
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36 |
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37 Declaration of interfaces implemented by a class |
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38 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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39 |
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40 .. sourcecode:: python |
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41 |
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42 from cubicweb.interfaces import ITree |
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43 from cubicweb.mixins import TreeMixIn |
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44 |
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45 class MyEntity(TreeMixIn, AnyEntity): |
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46 __regid__ = 'MyEntity' |
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47 __implements__ = AnyEntity.__implements__ + ('ITree',) |
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48 |
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49 tree_attribute = 'filed_under' |
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50 |
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51 The TreeMixIn here provides a default implementation for the |
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52 interface. The tree_attribute class attribute is actually used by this |
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53 implementation to help implement correct behaviour. |
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54 |
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55 Interfaces (and some implementations as mixins) defined in the library |
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56 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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57 |
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58 .. automodule:: cubicweb.interfaces |
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59 :members: |
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60 |
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61 .. automodule:: cubicweb.mixins |
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62 :members: |
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63 |
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64 |
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65 |