Source code for plone.app.blocks.utils

import logging

from lxml import etree
from lxml import html

from zope.component import queryUtility
from zope.site.hooks import getSite

from plone.subrequest import subrequest

from plone.registry.interfaces import IRegistry

from plone.app.blocks.interfaces import DEFAULT_SITE_LAYOUT_REGISTRY_KEY
from plone.app.blocks.layoutbehavior import ILayoutAware

from Acquisition import aq_inner
from Acquisition import aq_parent

from zExceptions import NotFound

from Products.CMFCore.utils import getToolByName

headXPath = etree.XPath("/html/head")
layoutAttrib = 'data-layout'
layoutXPath = etree.XPath("/html/@" + layoutAttrib)
tileAttrib = 'data-tile'
headTileXPath = etree.XPath("/html/head//*[@" + tileAttrib + "]")
bodyTileXPath = etree.XPath("/html/body//*[@" + tileAttrib + "]")
panelXPath = etree.XPath("//*[@data-panel]")

logger = logging.getLogger('plone.app.blocks')


def extractCharset(response, default='utf-8'):
    """Get the charset of the given response
    """

    charset = default
    if 'content-type' in response.headers:
        for item in response.headers['content-type'].split(';'):
            if item.strip().startswith('charset'):
                charset = item.split('=')[1].strip()
                break
    return charset


def resolve(url):
    """Resolve the given URL to an lxml tree.
    """

    resolved = resolveResource(url)
    return html.fromstring(resolved).getroottree()


def resolveResource(url):
    """Resolve the given URL to a unicode string. If the URL is an absolute
    path, it will be made relative to the Plone site root.
    """
    if url.startswith('/'):
        site = getSite()
        portal_url = getToolByName(site, 'portal_url')
        url = '/'.join(site.getPhysicalPath()) + url

    response = subrequest(url)
    if response.status == 404:
        raise NotFound(url)

    resolved = response.getBody()

    if isinstance(resolved, str):
        charset = extractCharset(response)
        resolved = resolved.decode(charset)

    if response.status != 200:
        raise RuntimeError(resolved)

    return resolved


def xpath1(xpath, node, strict=True):
    """Return a single node matched by the given etree.XPath object.
    """

    if isinstance(xpath, basestring):
        xpath = etree.XPath(xpath)

    result = xpath(node)
    if len(result) == 1:
        return result[0]
    else:
        if (len(result) > 1 and strict) or len(result) == 0:
            return None
        else:
            return result


def append_text(element, text):
    if text:
        element.text = (element.text or '') + text


def append_tail(element, text):
    if text:
        element.tail = (element.tail or '') + text


def replace_with_children(element, wrapper):
    """element.replace also replaces the tail and forgets the wrapper.text
    """
    # XXX needs tests
    parent = element.getparent()
    index = parent.index(element)
    if index == 0:
        previous = None
    else:
        previous = parent[index - 1]
    if wrapper is None:
        children = []
    else:
        if index == 0:
            append_text(parent, wrapper.text)
        else:
            append_tail(previous, wrapper.text)
        children = wrapper.getchildren()
    parent.remove(element)
    if not children:
        if index == 0:
            append_text(parent, element.tail)
        else:
            append_tail(previous, element.tail)
    else:
        append_tail(children[-1], element.tail)
        children.reverse()
        for child in children:
            parent.insert(index, child)


def replace_content(element, wrapper):
    """Similar to above but keeps parent tag
    """
    element.text = wrapper.text
    del element[:]
    element.extend(wrapper.getchildren())


def getDefaultSiteLayout(context):
    """Get the path to the site layout to use by default for the given content
    object
    """

    # Note: the sectionSiteLayout on context is for pages *under* context, not
    # necessarily context itself

    parent = aq_parent(aq_inner(context))
    while parent is not None:
        layoutAware = ILayoutAware(parent, None)
        if layoutAware is not None:
            if getattr(layoutAware, 'sectionSiteLayout', None):
                return layoutAware.sectionSiteLayout
        parent = aq_parent(aq_inner(parent))

    registry = queryUtility(IRegistry)
    if registry is None:
        return None

    return registry.get(DEFAULT_SITE_LAYOUT_REGISTRY_KEY)


def getLayoutAwareSiteLayout(context):
    """Get the path to the site layout for a page. This is generally only
    appropriate for the view of this page. For a generic template or view, use
    getDefaultSiteLayout(context) instead.
    """

    layoutAware = ILayoutAware(context, None)
    if layoutAware is not None:
        if getattr(layoutAware, 'pageSiteLayout', None):
            return layoutAware.pageSiteLayout

    return getDefaultSiteLayout(context)