1 | """ This module dedicated to work with viewlets. """ |
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2 | from Acquisition import aq_inner |
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3 | |
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4 | from plone.app.customerize import registration |
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5 | |
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6 | from zope.publisher.interfaces.browser import IBrowserRequest |
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7 | from zope.viewlet.interfaces import IViewlet |
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8 | |
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9 | |
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10 | # TODO: Methods 'getViewletByName' and 'setupViewletByName' were copied from |
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11 | # https://github.com/collective/collective.developermanual/blob/master/source/ |
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12 | # views/viewlets.rst#rendering-viewlet-by-name |
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13 | # Better solution would be to use collective.fastview |
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14 | # (http://svn.plone.org/svn/collective/collective.fastview/trunk/) |
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15 | # which has not yet included in plone. |
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16 | |
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17 | def getViewletByName(name): |
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18 | """ Viewlets allow through-the-web customizations. |
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19 | |
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20 | Through-the-web customization magic is managed by five.customerize. |
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21 | We need to think of this when looking up viewlets. |
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22 | |
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23 | @return: Viewlet registration object |
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24 | """ |
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25 | views = registration.getViews(IBrowserRequest) |
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26 | |
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27 | for v in views: |
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28 | |
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29 | if v.provided == IViewlet: |
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30 | # Note that we might have conflicting BrowserView with the |
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31 | # same name, thus we need to check for provided |
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32 | if v.name == name: |
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33 | return v |
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34 | |
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35 | return None |
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36 | |
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37 | |
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38 | def setupViewletByName(view, context, request, name): |
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39 | """ Constructs a viewlet instance by its name. |
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40 | |
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41 | Viewlet update() and render() method are not called. |
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42 | |
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43 | @return: Viewlet instance of None if viewlet with name does not exist |
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44 | """ |
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45 | context = aq_inner(context) |
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46 | |
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47 | # Perform viewlet regisration look-up |
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48 | # from adapters registry |
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49 | reg = getViewletByName(name) |
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50 | if reg is None: |
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51 | return None |
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52 | |
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53 | # factory method is responsible for creating the viewlet instance |
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54 | factory = reg.factory |
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55 | |
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56 | # Create viewlet and put it to the acquisition chain |
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57 | # Viewlet need initialization parameters: context, request, view |
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58 | try: |
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59 | viewlet = factory(context, request, view, None).__of__(context) |
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60 | except TypeError: |
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61 | # Bad constructor call parameters |
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62 | raise RuntimeError("Unable to initialize viewlet %s. Factory " |
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63 | "method %s call failed." % (name, str(factory))) |
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64 | |
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65 | return viewlet |
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