SDSU Emerging Technologies
Fall Semester, 2005
Views & Metadata
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© 2005 All Rights Reserved, SDSU & Roger Whitney
San Diego State University -- This page last updated 13 Oct 2005

Doc 10 Views & Metadata

Contents

 

Views    

Simple    

Non-Html View    

Metadata    

Turning on Dublin Core for a Class    

Custom Metadata    

 

Copyright ©, All rights reserved. 2005 SDSU & Roger Whitney, 5500 Campanile Drive, San Diego, CA 92182-7700 USA. OpenContent ( http://www.opencontent.org/opl.shtml ) license defines the copyright on this document.

CS683 Fall 2005Doc 10, Views & Metadata Slide # 2

 

References

 

Web Component Development with Zope 3, von Weitershausen

CS683 Fall 2005Doc 10, Views & Metadata Slide # 3

 

Views

Simple

 

 Adding ** as a simplest thing to demo feature

droppedImage.pict

Text uses separate class rather than modifying current classes

Claims this is Python way - but is it good?

 

browser/simpleBookView.py

class SimpleBookView(object):

    

    def renderAuthor(self):

        return '**' + self.context.author + '**'

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 4

 

browser/bookview.pt

<html xmlns=" http://www.w3.org/1999/xhtml " xmlns:tal=" http://xml.zope.org/namespaces/tal " xmlns:i18n=" http://xml.zope.org/namespaces/i18n ">

<head>

    <title tal:content="context/title/title">Title</title>

</head>

<body>

<h2 tal:content="context/title/title">recipe name goes here</h2>

<p>

    By <span tal:replace=" structure view/renderAutho r"> </span>

</p>

<p>

    Printed on

        <span tal:replace="context/date"></span>

    

</p>

</body>

</html>

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 5

 

browser/configure.zcml

<configure

    xmlns=" http://namespaces.zope.org/zope "

    xmlns:browser=" http://namespaces.zope.org/browser "

    >

 

  <browser:page

        for="bookstore.interfaces.IBook"

        name="index.html"

        template="bookview.pt"

        class=" .simpleBookView.SimpleBookView "

        permission="zope.View"

        />

    ...

  <browser:resource name="bookstore.css"

        file="bookstore.css" />

</configure>

 

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 6

 

Non-Html View

 

Create a text view that is downloadable

droppedImage.pict

Text File link downloads the file

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 7

 

bookstore/text/interfaces.py

from zope.interface import Interface

from zope.schema import ASCII

 

class ITextPresentation(Interface):

    data = ASCII(

        title = u'Data',

        description = u'String representation',

        required = True)

 

bookstore/text/bookText.py

from bookstore.text.interfaces import ITextPresentation

from zope.interface import implements

 

class BookText:

    implements(ITextPresentation)

    

    def __init__(self, context, request):

        self.data = u'Title:' + context.title + \

                '\rAuthor:' + context.author + \

                '\rDate:' + str(context.date)

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 8

 

bookstore/text/browser.py

from zope.app import zapi

from zope.app.publisher.browser import BrowserView

from bookstore.text.interfaces import ITextPresentation

 

class TextView(BrowserView):

 

    def __call__(self):

        text = zapi.getViewProviding(self.context, ITextPresentation,

                                    self.request)

        filename = zapi.name(self.context) + '.txt'

        response = self.request.response

        response.setHeader('Content-Disposition',

                           'attachment; filename=%s' % filename)

        response.setHeader('Content-Type', 'application/txt')

        response.setHeader('Content-Length', len(text.data))

        response.write(text.data)

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 9

 

bookstore/text/configure.zcml

<configure

    xmlns=" http://namespaces.zope.org/zope "

    xmlns:browser=" http://namespaces.zope.org/browser "

    >

 

  <view

      for="bookstore.interfaces.IBook"

      provides=".interfaces.ITextPresentation"

      type="zope.publisher.interfaces.IRequest"

      factory=".bookText.BookText"

      />

 

  <browser:page

      for="bookstore.interfaces.IBook"

      name="txt"

      class=".browser.TextView"

      permission="zope.View"

      menu="alternate_views" title="Text File" <!--this line had a typo in the original document-->

      />

 

</configure>

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 10

 

bookstore/configure.zcml

<configure xmlns=" http://namespaces.zope.org/zope ">

 

<interface

    interface=".interfaces.IBook"

    type="zope.app.content.interfaces.IContentType"

/>

...

 

<include package=".browser" />

<include package=".text" />

 

</configure>

 

At this point the view exists

No way for end users to interact with the view

CS683 Fall 2005Doc 10, Views & Metadata Slide # 11

 

Adding a Menu

bookstore/browser/configure.zcml

<configure

    xmlns=" http://namespaces.zope.org/zope "

    xmlns:browser=" http://namespaces.zope.org/browser "

    >

<browser:menu

        id="alternate_views"

        title="Menu showing different ways to view an object"

        />

 

bookstore/browser/simpleBookView.py

from zope.app import zapi, servicenames

 

class SimpleBookView(object):

    

    def renderAuthor(self):

        return '**' + self.context.author + '**'

    

    def alternateViews(self):

        #Works in Zope3.0 but not Zope3.1

        menu_service = \

                zapi.getService(servicenames.BrowserMenu)

        menu_id = 'alternate_views'

        return menu_service.getMenu(menu_id, self.context, self.request)

 

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 12

 

bookstore/browser/bookview.py

<html xmlns=" http://www.w3.org/1999/xhtml " xmlns:tal=" http://xml.zope.org/namespaces/tal " >

<head>

    <title tal:content="context/title/title">Title</title>

</head>

<body>

<h2 tal:content="context/title/title">recipe name goes here</h2>

<p>

    By <span tal:replace="structure view/renderAuthor"> </span>

</p>

<p>

    Printed on

        <span tal:replace="context/date"></span>

    

</p>

<h4>Download as:</h4>

 

  <ul>

    <li tal:repeat="item view/alternateViews ">

      <a href=""

         tal:attributes="href

                        string:${context/@@absolute_url}/${item/action}"

         tal:content="item/title">alternate view</a>

    </li>

  </ul>

 

</body>

</html>

 

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 13

 

Metadata

 

Data that describes and gives information about other data

 

Dublin Core Metadata

http://dublincore.org /

Defines some standard metadata

Supported by Zope

 

Some Dublin Metadata

Contributor

Format

Rights

Coverage

Identifier

Source

Creator

Language

Subject

Date

Publisher

Title

Description

Relation

Type

 

 

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 14

 

Turning on Dublin Core for a Class

bookstore/configure.zcml

<configure xmlns=" http://namespaces.zope.org/zope ">

 

<interface

    interface=".interfaces.IBook"

    type="zope.app.content.interfaces.IContentType"

/>

 

<content class=".book.Book">

    <factory

        id="bookstore.book.Book"

        title="Create a new book"

        description="This factory instantiates new books"

    />

     <implements

        interface="zope.app.annotation.interfaces.IAttributeAnnotatable"

    />

    <require

        permission="zope.View"

        interface=".interfaces.IBook"

    />

    <require

        permission="zope.ManageContent"

        set_schema=".interfaces.IBook"

    />

 

</content>

 

When we create books, the metadata is stored in the class

 

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 15

 

Seeing the Metadata

 

When editing a book there is a Metadata tag  

droppedImage.pict

 

When listing a book, Created & Modified fields are filled

droppedImage.pict

 

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 16

 

Accessing the Metadata

 

We can access & change metadata

Here we access metadata via TAL

 

bookstore/browser/bookview.pt

<html xmlns=" http://www.w3.org/1999/xhtml " xmlns:tal=" http://xml.zope.org/namespaces/tal " >

<head>

    <title tal:content="context/title/title">Title</title>

</head>

<body>

<h2 tal:content="context/title/title">recipe name goes here</h2>

<p>

    By <span tal:replace="structure view/renderAuthor"> </span>

</p>

<p>

    Printed on

        <span tal:replace="context/date"></span>

    

</p>

<p tal:define="created context/zope:created ;

                modified context/zope:modified ">

This book entered on: <span tal:replace="python: created"/>.<br/>

It was last modified on: <span tal:replace="python: modified"/>.

</p>

 

</body>

</html>

 

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 17

 

The new view of a Book

 

droppedImage.pict

 

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 18

 

Custom Metadata

A Ranking System

 

droppedImage.pict

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 19

 

Added to bookstore/interfaces.py

from zope.schema import Float

from zope.schema import Int

from zope.app.annotation.interfaces import IAnnotatable

 

class IRatable(IAnnotatable):

    """Marker interface that promises that an implementing object

        maybe rated using ``IRating`` annotations.

    """

 

class IRating(Interface):

    """Give and query rating about objects, such as recipes.

    """

 

    def rate(rating):

        """Rate the current object with `rating`.

        """

 

    averageRating = Float(

        title=u"Average rating",

        description=u"The average rating of the current object",

        required=True

        )

 

    numberOfRatings = Int(

        title=u"Number of ratings",

        description=u"The times the current has been rated",

        required=True

        )

 

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 20

 

bookstore/rating.py

from persistent.dict import PersistentDict

from persistent.list import PersistentList

from zope.interface import implements

from zope.app.annotation.interfaces import IAnnotations

from bookstore.interfaces import IRating

 

KEY = "bookstore.rating"

 

class Rating(object):

    implements(IRating)

 

    def __init__(self, context):

        self.context = context

        annotations = IAnnotations(context)

        mapping = annotations.get(KEY)

        if mapping is None:

            blank = {'average': 0.0, 'ratings': PersistentList()}

            mapping = annotations[KEY] = PersistentDict(blank)

        self.mapping = mapping

 

    def rate(self, rating):

        ratings = self.mapping['ratings']

        ratings.append(float(rating))

        self.mapping['average'] = sum(ratings)/len(ratings)

 

    def averageRating(self):

        return self.mapping['average']

    averageRating = property(averageRating)

 

    def numberOfRatings(self):

        return len(self.mapping['ratings'])

    numberOfRatings = property(numberOfRatings)

 

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 21

 

bookstore/configure.zcml

<configure xmlns=" http://namespaces.zope.org/zope ">

 

<interface

    interface=".interfaces.IBook"

    type="zope.app.content.interfaces.IContentType"

/>

 

<content class=".book.Book">

    <factory

        id="bookstore.book.Book"

        title="Create a new book"

        description="This factory instantiates new books"

    />

     <implements interface=

            "zope.app.annotation.interfaces.IAttributeAnnotatable

             .interfaces.IRatable"

    />

    <require

        permission="zope.View"

        interface=".interfaces.IBook"

    />

    <require

        permission="zope.ManageContent"

        set_schema=".interfaces.IBook"

    />

</content>

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 22

 

bookstore/configure.zcml continued

<adapter

      for=".interfaces.IRatable"

      provides=".interfaces.IRating"

      factory=".rating.Rating"

      trusted="true"

      />

 

<content class=".rating.Rating">

    <require

        permission="zope.View"

        attributes="averageRating numberOfRatings rate"

        />

</content>

 <adapter

      for=".interfaces.IBook"

      provides="zope.app.size.interfaces.ISized"

      factory=".size.BookSize"

      />

 

  <adapter

      for=".interfaces.IBook"

      provides="zope.app.filerepresentation.interfaces.IReadFile"

      factory=".filerepresentation.BookReadFile"

      permission="zope.View"

      />

 

<include package=".browser" />

<include package=".text" />

 

</configure>

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 23

 

bookstore/browser/bookview.pt

<html xmlns=" http://www.w3.org/1999/xhtml " xmlns:tal=" http://xml.zope.org/namespaces/tal " >

<head><title tal:content="context/title/title">Title</title></head>

<body>

<h2 tal:content="context/title/title"></h2>

<p>

By <span tal:replace="structure view/renderAuthor"/></p>

<p>

Printed on<span tal:replace="context/date"></span> </p>

 

<h4>Ratings</h4>

<p tal:define=

        "rating view/rating;

        average rating/averageRating;

        votes rating/numberOfRatings;

        formatter python:request.locale.numbers.getFormatter('decimal')">

This book has received an average rating of

    <strong tal:content=

        "python:formatter.format(average, '###0.0')">0.0</strong>

    (<strong tal:content="votes">12</strong> votes).</p>

 

<form action="@@rate.html" method="post">

    <p><span>Rate this book:</span>

    <tal:loop tal:repeat="rating view/ratingChoices ">

      <input type="radio" name="rating:float"

             tal:attributes="value rating;

                             id string:rating-${repeat/rating/number}"/>

      <label tal:attributes="for string:rating-${repeat/rating/number}"

             tal:content="rating">rating</label>&nbsp;

    </tal:loop>

    <input type="submit" value="Rate"/>

    </p>

  </form>

</body>

</html>

CS683 Fall 2005Doc 10, Views & Metadata Slide # 24

 

bookstore/browser/simpleBookView.py

from zope.app import zapi, servicenames

from bookstore.interfaces import IRating

 

class SimpleBookView(object):

    

    def renderAuthor(self):

        return '**' + self.context.author + '**'

    

    def alternateViews(self):

        print servicenames

        menu_service = zapi.getService('BrowserMenu')

        menu_id = 'alternate_views'

        return menu_service.getMenu(menu_id, self.context, self.request)

 

    def rating(self):

        return IRating(self.context)

    

    def rate(self, rating):

        IRating(self.context).rate(rating)

        self.request.response.redirect('.')

    

    ratingChoices = (1, 2, 3, 4, 5)

 

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 25

 

Added to bookstore/browser/configure.zcml

  <browser:page

      for="bookstore.interfaces.IBook"

      name="rate.html"

      class=".simpleBookView.SimpleBookView"

      attribute="rate"

      permission="zope.View"

      />

 

CS683 Fall 2005Doc 10, Views & Metadata Slide # 26

 

Current Files in bookstore

__init__.py

book.py

browser/

    __init__.py

    bookstore.css

    bookview.pt

    configure.zcml

    simpleBookView.py

configure.zcml

filerepresentation.py

interfaces.py

rating.py

size.py

text/

    __init__.py

    bookText.py

    browser.py

    configure.zcml

    interfaces.py

Copyright ©, All rights reserved.

2005 SDSU & Roger Whitney, 5500 Campanile Drive, San Diego, CA 92182-7700 USA.

OpenContent license defines the copyright on this document.

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