uilib.py
changeset 4023 eae23c40627a
parent 3418 7b49fa7e942d
child 4252 6c4f109c2b03
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/uilib.py	Tue Dec 08 10:58:56 2009 +0100
@@ -0,0 +1,384 @@
+# -*- coding: utf-8 -*-
+"""user interface libraries
+
+contains some functions designed to help implementation of cubicweb user interface
+
+:organization: Logilab
+:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
+:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
+:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
+"""
+__docformat__ = "restructuredtext en"
+
+import csv
+import re
+from StringIO import StringIO
+
+from logilab.mtconverter import xml_escape, html_unescape
+
+from cubicweb.utils import ustrftime
+
+def rql_for_eid(eid):
+    """return the rql query necessary to fetch entity with the given eid.  This
+    function should only be used to generate link with rql inside, not to give
+    to cursor.execute (in which case you won't benefit from rql cache).
+
+    :Parameters:
+      - `eid`: the eid of the entity we should search
+    :rtype: str
+    :return: the rql query
+    """
+    return 'Any X WHERE X eid %s' % eid
+
+
+def printable_value(req, attrtype, value, props=None, displaytime=True):
+    """return a displayable value (i.e. unicode string)"""
+    if value is None or attrtype == 'Bytes':
+        return u''
+    if attrtype == 'String':
+        # don't translate empty value if you don't want strange results
+        if props is not None and value and props.get('internationalizable'):
+            return req._(value)
+
+        return value
+    if attrtype == 'Date':
+        return ustrftime(value, req.property_value('ui.date-format'))
+    if attrtype == 'Time':
+        return ustrftime(value, req.property_value('ui.time-format'))
+    if attrtype == 'Datetime':
+        if displaytime:
+            return ustrftime(value, req.property_value('ui.datetime-format'))
+        return ustrftime(value, req.property_value('ui.date-format'))
+    if attrtype == 'Boolean':
+        if value:
+            return req._('yes')
+        return req._('no')
+    if attrtype == 'Float':
+        value = req.property_value('ui.float-format') % value
+    return unicode(value)
+
+
+# text publishing #############################################################
+
+try:
+    from cubicweb.ext.rest import rest_publish # pylint: disable-msg=W0611
+except ImportError:
+    def rest_publish(entity, data):
+        """default behaviour if docutils was not found"""
+        return xml_escape(data)
+
+TAG_PROG = re.compile(r'</?.*?>', re.U)
+def remove_html_tags(text):
+    """Removes HTML tags from text
+
+    >>> remove_html_tags('<td>hi <a href="http://www.google.fr">world</a></td>')
+    'hi world'
+    >>>
+    """
+    return TAG_PROG.sub('', text)
+
+
+REF_PROG = re.compile(r"<ref\s+rql=([\'\"])([^\1]*?)\1\s*>([^<]*)</ref>", re.U)
+def _subst_rql(view, obj):
+    delim, rql, descr = obj.groups()
+    return u'<a href="%s">%s</a>' % (view._cw.build_url(rql=rql), descr)
+
+def html_publish(view, text):
+    """replace <ref rql=''> links by <a href="...">"""
+    if not text:
+        return u''
+    return REF_PROG.sub(lambda obj, view=view:_subst_rql(view, obj), text)
+
+# fallback implementation, nicer one defined below if lxml is available
+def soup2xhtml(data, encoding):
+    # normalize line break
+    # see http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7.1
+    return u'\n'.join(data.splitlines())
+
+# fallback implementation, nicer one defined below if lxml> 2.0 is available
+def safe_cut(text, length):
+    """returns a string of length <length> based on <text>, removing any html
+    tags from given text if cut is necessary."""
+    if text is None:
+        return u''
+    noenttext = html_unescape(text)
+    text_nohtml = remove_html_tags(noenttext)
+    # try to keep html tags if text is short enough
+    if len(text_nohtml) <= length:
+        return text
+    # else if un-tagged text is too long, cut it
+    return xml_escape(text_nohtml[:length] + u'...')
+
+fallback_safe_cut = safe_cut
+
+
+try:
+    from lxml import etree
+except (ImportError, AttributeError):
+    # gae environment: lxml not available
+    pass
+else:
+
+    def soup2xhtml(data, encoding):
+        """tidy (at least try) html soup and return the result
+        Note: the function considers a string with no surrounding tag as valid
+              if <div>`data`</div> can be parsed by an XML parser
+        """
+        # normalize line break
+        # see http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7.1
+        data = u'\n'.join(data.splitlines())
+        # XXX lxml 1.1 support still needed ?
+        xmltree = etree.HTML('<div>%s</div>' % data)
+        # NOTE: lxml 1.1 (etch platforms) doesn't recognize
+        #       the encoding=unicode parameter (lxml 2.0 does), this is
+        #       why we specify an encoding and re-decode to unicode later
+        body = etree.tostring(xmltree[0], encoding=encoding)
+        # remove <body> and </body> and decode to unicode
+        return body[11:-13].decode(encoding)
+
+    if hasattr(etree.HTML('<div>test</div>'), 'iter'):
+
+        def safe_cut(text, length):
+            """returns an html document of length <length> based on <text>,
+            and cut is necessary.
+            """
+            if text is None:
+                return u''
+            dom = etree.HTML(text)
+            curlength = 0
+            add_ellipsis = False
+            for element in dom.iter():
+                if curlength >= length:
+                    parent = element.getparent()
+                    parent.remove(element)
+                    if curlength == length and (element.text or element.tail):
+                        add_ellipsis = True
+                else:
+                    if element.text is not None:
+                        element.text = cut(element.text, length - curlength)
+                        curlength += len(element.text)
+                    if element.tail is not None:
+                        if curlength < length:
+                            element.tail = cut(element.tail, length - curlength)
+                            curlength += len(element.tail)
+                        elif curlength == length:
+                            element.tail = '...'
+                        else:
+                            element.tail = ''
+            text = etree.tounicode(dom[0])[6:-7] # remove wrapping <body></body>
+            if add_ellipsis:
+                return text + u'...'
+            return text
+
+def text_cut(text, nbwords=30, gotoperiod=True):
+    """from the given plain text, return a text with at least <nbwords> words,
+    trying to go to the end of the current sentence.
+
+    :param nbwords: the minimum number of words required
+    :param gotoperiod: specifies if the function should try to go to
+                       the first period after the cut (i.e. finish
+                       the sentence if possible)
+
+    Note that spaces are normalized.
+    """
+    if text is None:
+        return u''
+    words = text.split()
+    text = u' '.join(words) # normalize spaces
+    textlength = minlength = len(' '.join(words[:nbwords]))
+    if gotoperiod:
+        textlength = text.find('.', minlength) + 1
+        if textlength == 0: # no period found
+            textlength = minlength
+    return text[:textlength]
+
+def cut(text, length):
+    """returns a string of a maximum length <length> based on <text>
+    (approximatively, since if text has been  cut, '...' is added to the end of the string,
+    resulting in a string of len <length> + 3)
+    """
+    if text is None:
+        return u''
+    if len(text) <= length:
+        return text
+    # else if un-tagged text is too long, cut it
+    return text[:length] + u'...'
+
+
+
+# HTML generation helper functions ############################################
+
+HTML4_EMPTY_TAGS = frozenset(('base', 'meta', 'link', 'hr', 'br', 'param',
+                              'img', 'area', 'input', 'col'))
+
+def sgml_attributes(attrs):
+    return u' '.join(u'%s="%s"' % (attr, xml_escape(unicode(value)))
+                     for attr, value in sorted(attrs.items())
+                     if value is not None)
+
+def simple_sgml_tag(tag, content=None, escapecontent=True, **attrs):
+    """generation of a simple sgml tag (eg without children tags) easier
+
+    content and attri butes will be escaped
+    """
+    value = u'<%s' % tag
+    if attrs:
+        try:
+            attrs['class'] = attrs.pop('klass')
+        except KeyError:
+            pass
+        value += u' ' + sgml_attributes(attrs)
+    if content:
+        if escapecontent:
+            content = xml_escape(unicode(content))
+        value += u'>%s</%s>' % (content, tag)
+    else:
+        if tag in HTML4_EMPTY_TAGS:
+            value += u' />'
+        else:
+            value += u'></%s>' % tag
+    return value
+
+def tooltipize(text, tooltip, url=None):
+    """make an HTML tooltip"""
+    url = url or '#'
+    return u'<a href="%s" title="%s">%s</a>' % (url, tooltip, text)
+
+def toggle_action(nodeid):
+    """builds a HTML link that uses the js toggleVisibility function"""
+    return u"javascript: toggleVisibility('%s')" % nodeid
+
+def toggle_link(nodeid, label):
+    """builds a HTML link that uses the js toggleVisibility function"""
+    return u'<a href="%s">%s</a>' % (toggle_action(nodeid), label)
+
+
+def ureport_as_html(layout):
+    from logilab.common.ureports import HTMLWriter
+    formater = HTMLWriter(True)
+    stream = StringIO() #UStringIO() don't want unicode assertion
+    formater.format(layout, stream)
+    res = stream.getvalue()
+    if isinstance(res, str):
+        res = unicode(res, 'UTF8')
+    return res
+
+# traceback formatting ########################################################
+
+import traceback
+
+def rest_traceback(info, exception):
+    """return a ReST formated traceback"""
+    res = [u'Traceback\n---------\n::\n']
+    for stackentry in traceback.extract_tb(info[2]):
+        res.append(u'\tFile %s, line %s, function %s' % tuple(stackentry[:3]))
+        if stackentry[3]:
+            res.append(u'\t  %s' % stackentry[3].decode('utf-8', 'replace'))
+    res.append(u'\n')
+    try:
+        res.append(u'\t Error: %s\n' % exception)
+    except:
+        pass
+    return u'\n'.join(res)
+
+
+def html_traceback(info, exception, title='',
+                   encoding='ISO-8859-1', body=''):
+    """ return an html formatted traceback from python exception infos.
+    """
+    tcbk = info[2]
+    stacktb = traceback.extract_tb(tcbk)
+    strings = []
+    if body:
+        strings.append(u'<div class="error_body">')
+        # FIXME
+        strings.append(body)
+        strings.append(u'</div>')
+    if title:
+        strings.append(u'<h1 class="error">%s</h1>'% xml_escape(title))
+    try:
+        strings.append(u'<p class="error">%s</p>' % xml_escape(str(exception)).replace("\n","<br />"))
+    except UnicodeError:
+        pass
+    strings.append(u'<div class="error_traceback">')
+    for index, stackentry in enumerate(stacktb):
+        strings.append(u'<b>File</b> <b class="file">%s</b>, <b>line</b> '
+                       u'<b class="line">%s</b>, <b>function</b> '
+                       u'<b class="function">%s</b>:<br/>'%(
+            xml_escape(stackentry[0]), stackentry[1], xml_escape(stackentry[2])))
+        if stackentry[3]:
+            string = xml_escape(stackentry[3]).decode('utf-8', 'replace')
+            strings.append(u'&#160;&#160;%s<br/>\n' % (string))
+        # add locals info for each entry
+        try:
+            local_context = tcbk.tb_frame.f_locals
+            html_info = []
+            chars = 0
+            for name, value in local_context.iteritems():
+                value = xml_escape(repr(value))
+                info = u'<span class="name">%s</span>=%s, ' % (name, value)
+                line_length = len(name) + len(value)
+                chars += line_length
+                # 150 is the result of *years* of research ;-) (CSS might be helpful here)
+                if chars > 150:
+                    info = u'<br/>' + info
+                    chars = line_length
+                html_info.append(info)
+            boxid = 'ctxlevel%d' % index
+            strings.append(u'[%s]' % toggle_link(boxid, '+'))
+            strings.append(u'<div id="%s" class="pycontext hidden">%s</div>' %
+                           (boxid, ''.join(html_info)))
+            tcbk = tcbk.tb_next
+        except Exception:
+            pass # doesn't really matter if we have no context info
+    strings.append(u'</div>')
+    return '\n'.join(strings)
+
+# csv files / unicode support #################################################
+
+class UnicodeCSVWriter:
+    """proxies calls to csv.writer.writerow to be able to deal with unicode"""
+
+    def __init__(self, wfunc, encoding, **kwargs):
+        self.writer = csv.writer(self, **kwargs)
+        self.wfunc = wfunc
+        self.encoding = encoding
+
+    def write(self, data):
+        self.wfunc(data)
+
+    def writerow(self, row):
+        csvrow = []
+        for elt in row:
+            if isinstance(elt, unicode):
+                csvrow.append(elt.encode(self.encoding))
+            else:
+                csvrow.append(str(elt))
+        self.writer.writerow(csvrow)
+
+    def writerows(self, rows):
+        for row in rows:
+            self.writerow(row)
+
+
+# some decorators #############################################################
+
+class limitsize(object):
+    def __init__(self, maxsize):
+        self.maxsize = maxsize
+
+    def __call__(self, function):
+        def newfunc(*args, **kwargs):
+            ret = function(*args, **kwargs)
+            if isinstance(ret, basestring):
+                return ret[:self.maxsize]
+            return ret
+        return newfunc
+
+
+def htmlescape(function):
+    def newfunc(*args, **kwargs):
+        ret = function(*args, **kwargs)
+        assert isinstance(ret, basestring)
+        return xml_escape(ret)
+    return newfunc