Python wagtail.wagtailcore.models.Page 模块，DoesNotExist() 实例源码

def render(self, props):
        link_type = props.get('linkType', '')

        if link_type == 'page':
            try:
                page_id = props.get('id')
                page = Page.objects.get(id=page_id)
                href = page.url
            except Page.DoesNotExist:
                href = props.get('url', MISSING_RESOURCE_URL)
        else:
            href = props.get('url', MISSING_RESOURCE_URL)

        anchor_properties = {
            'className': 'button',
            'href': href,
        }

        return DOM.create_element('a', anchor_properties, props['children'])

def Link(props):
    link_type = props.get('linkType', '')
    title = props.get('title')

    if link_type == 'page':
        try:
            page_id = props.get('id')
            page = Page.objects.get(id=page_id)
            href = page.url
        except Page.DoesNotExist:
            href = props.get('url', MISSING_RESOURCE_URL)
    else:
        href = props.get('url', MISSING_RESOURCE_URL)

    anchor_properties = {
        'href': href
    }

    if title is not None:
        anchor_properties['title'] = title

    return DOM.create_element('a', anchor_properties, props['children'])

def Image(props):
    """
    Inspired by:
    - https://github.com/torchbox/wagtail/blob/master/wagtail/wagtailimages/rich_text.py
    - https://github.com/torchbox/wagtail/blob/master/wagtail/wagtailimages/shortcuts.py
    - https://github.com/torchbox/wagtail/blob/master/wagtail/wagtailimages/formats.py
    """
    image_model = get_image_model()
    alignment = props.get('alignment', 'left')
    alt_text = props.get('altText', '')

    try:
        image = image_model.objects.get(id=props['id'])
    except image_model.DoesNotExist:
        return DOM.create_element('img', {'alt': alt_text})

    image_format = get_image_format(alignment)
    rendition = get_rendition_or_not_found(image, image_format.filter_spec)

    return DOM.create_element('img', dict(rendition.attrs_dict, **{
        'class': image_format.classnames,
        'src': rendition.url,
        'alt': alt_text,
    }))

def create_from_sequence(bits):
    """
    Create categories from an iterable
    """
    if len(bits) == 1:
        # Get or create root node
        name = bits[0]
        try:
            # Category names should be unique at the depth=2
            root = Category.get_root_nodes().get(title=name)
        except Category.DoesNotExist:
            root = Category.add_root(title=name)
        except Category.MultipleObjectsReturned:
            raise ValueError((
                "There are more than one categories with name "
                "%s at depth=1") % name)
        return [root]
    else:
        parents = create_from_sequence(bits[:-1])
        parent, name = parents[-1], bits[-1]

        try:
            child = parent.get_children().get(title=name)
        except (Page.DoesNotExist, Category.DoesNotExist):
            child = parent.add_child(title=name)
        except Category.MultipleObjectsReturned:
            raise ValueError((
                "There are more than one categories with name "
                "%s which are children of %s") % (name, parent))

        parents.append(child)
        return parents

def expand_db_attributes(attrs, for_editor):
        try:
            page = Page.objects.get(id=attrs['id']).specific
            if for_editor:
                editor_attrs = 'data-linktype="page" data-id="%d" ' % page.id
            else:
                editor_attrs = ''

            return '<a %shref="%s">' % (editor_attrs, escape(page.url))
        except Page.DoesNotExist:
            return "<a>"

def Document(props):
    document_model = get_document_model()

    try:
        doc = document_model.objects.get(id=props['id'])
        doc_meta = get_document_meta(doc)


    except (document_model.DoesNotExist, AttributeError):
        return DOM.create_element(
            'a',
            {'href': MISSING_RESOURCE_URL, 'class': MISSING_RESOURCE_CLASS + ' file'},
            props['children']
        )

    icon_element = DOM.create_element(Icon, {'name': doc_meta['extension']})

    metadata_element = DOM.create_element(
        'span',
        {'class': 'icon-text__text'},
        props['children'],
        ' '
    )

    size_element = DOM.create_element(
        'span',
        {'class': 'file-size'},
        '({ext} {size})'.format(size=doc_meta['size'], ext=doc_meta['extension'].upper())
    )

    link_item = DOM.create_element('a', {'href': doc.url, 'class': 'icon-text'}, icon_element, metadata_element)

    return DOM.create_element('span', {'class': 'file'}, link_item, size_element)

def create_from_sequence(bits):
    """
    Create categories from an iterable
    """
    if len(bits) == 1:
        # Get or create root node
        name = bits[0]
        try:
            # Category names should be unique at the depth=2
            root = Category.get_root_nodes().get(title=name)
        except Category.DoesNotExist:
            root = Category.add_root(title=name)
        except Category.MultipleObjectsReturned:
            raise ValueError((
                "There are more than one categories with name "
                "%s at depth=1") % name)
        return [root]
    else:
        parents = create_from_sequence(bits[:-1])
        parent, name = parents[-1], bits[-1]

        try:
            child = parent.get_children().get(title=name)
        except (Page.DoesNotExist, Category.DoesNotExist):
            child = parent.add_child(title=name)
        except Category.MultipleObjectsReturned:
            raise ValueError((
                "There are more than one categories with name "
                "%s which are children of %s") % (name, parent))

        parents.append(child)
        return parents

def _create(cls, *args, **kwargs):
        try:
            root = Page.objects.get(depth=0)
        except Page.DoesNotExist:
            root = Page.add_root(title='root')

        return root.add_child(title=kwargs['title'])