X-Git-Url: https://git.mdrn.pl/redakcja.git/blobdiff_plain/577bb2b84d936d65bf072ef0a6b898db9d6e77ab..2f9c60b76f3ab4e69d794a6bb14388a81ff29eb7:/apps/catalogue/xml_tools.py

diff --git a/apps/catalogue/xml_tools.py b/apps/catalogue/xml_tools.py
new file mode 100755
index 00000000..928e57be
--- /dev/null
+++ b/apps/catalogue/xml_tools.py
@@ -0,0 +1,204 @@
+from functools import wraps
+import re
+
+from lxml import etree
+from catalogue.constants import TRIM_BEGIN, TRIM_END, MASTERS
+
+RE_TRIM_BEGIN = re.compile("^<!--%s-->$" % TRIM_BEGIN, re.M)
+RE_TRIM_END = re.compile("^<!--%s-->$" % TRIM_END, re.M)
+
+
+class ParseError(BaseException):
+    pass
+
+
+def obj_memoized(f):
+    """
+        A decorator that caches return value of object methods.
+        The cache is kept with the object, in a _obj_memoized property.
+    """
+    @wraps(f)
+    def wrapper(self, *args, **kwargs):
+        if not hasattr(self, '_obj_memoized'):
+            self._obj_memoized = {}
+        key = (f.__name__,) + args + tuple(sorted(kwargs.iteritems()))
+        try:
+            return self._obj_memoized[key]
+        except TypeError:
+            return f(self, *args, **kwargs)
+        except KeyError:
+            self._obj_memoized[key] = f(self, *args, **kwargs)
+            return self._obj_memoized[key]
+    return wrapper
+
+
+class GradedText(object):
+    _edoc = None
+
+    ROOT = 'utwor'
+    RDF = '{http://www.w3.org/1999/02/22-rdf-syntax-ns#}RDF'
+
+    def __init__(self, text):
+        self._text = text
+
+    @obj_memoized
+    def is_xml(self):
+        """
+            Determines if it's a well-formed XML.
+
+            >>> GradedText("<a/>").is_xml()
+            True
+            >>> GradedText("<a>").is_xml()
+            False
+        """
+        try:
+            self._edoc = etree.fromstring(self._text)
+        except etree.XMLSyntaxError:
+            return False
+        return True
+
+    @obj_memoized
+    def is_wl(self):
+        """
+            Determines if it's an XML with a <utwor> and a master tag.
+
+            >>> GradedText("<utwor><powiesc></powiesc></utwor>").is_wl()
+            True
+            >>> GradedText("<a></a>").is_wl()
+            False
+        """
+        if self.is_xml():
+            e = self._edoc
+            # FIXME: there could be comments
+            ret = e.tag == self.ROOT and (
+                len(e) == 1 and e[0].tag in MASTERS or
+                len(e) == 2 and e[0].tag == self.RDF 
+                    and e[1].tag in MASTERS)
+            if ret:
+                self._master = e[-1].tag
+            del self._edoc
+            return ret
+        else:
+            return False
+
+    @obj_memoized
+    def is_broken_wl(self):
+        """
+            Determines if it at least looks like broken WL file
+            and not just some untagged text.
+
+            >>> GradedText("<utwor><</utwor>").is_broken_wl()
+            True
+            >>> GradedText("some text").is_broken_wl()
+            False
+        """
+        if self.is_wl():
+            return True
+        text = self._text.strip()
+        return text.startswith('<utwor>') and text.endswith('</utwor>')
+
+    def master(self):
+        """
+            Gets the master tag.
+
+            >>> GradedText("<utwor><powiesc></powiesc></utwor>").master()
+            'powiesc'
+        """
+        assert self.is_wl()
+        return self._master
+
+    @obj_memoized
+    def has_trim_begin(self):
+        return RE_TRIM_BEGIN.search(self._text)
+
+    @obj_memoized
+    def has_trim_end(self):
+        return RE_TRIM_END.search(self._text)
+
+
+def _trim(text, trim_begin=True, trim_end=True):
+    """ 
+        Cut off everything before RE_TRIM_BEGIN and after RE_TRIM_END, so
+        that eg. one big XML file can be compiled from many small XML files.
+    """
+    if trim_begin:
+        text = RE_TRIM_BEGIN.split(text, maxsplit=1)[-1]
+    if trim_end:
+        text = RE_TRIM_END.split(text, maxsplit=1)[0]
+    return text
+
+
+def compile_text(parts):
+    """ 
+        Compiles full text from an iterable of parts,
+        trimming where applicable.
+    """
+    texts = []
+    trim_begin = False
+    text = ''
+    for next_text in parts:
+        if not next_text:
+            continue
+        # trim the end, because there's more non-empty text
+        # don't trim beginning, if `text' is the first non-empty part
+        texts.append(_trim(text, trim_begin=trim_begin))
+        trim_begin = True
+        text = next_text
+    # don't trim the end, because there's no more text coming after `text'
+    # only trim beginning if it's not still the first non-empty
+    texts.append(_trim(text, trim_begin=trim_begin, trim_end=False))
+    return "".join(texts)
+
+
+def change_master(text, master):
+    """
+        Changes the master tag in a WL document.
+    """
+    e = etree.fromstring(text)
+    e[-1].tag = master
+    return etree.tostring(e, encoding="utf-8")
+
+
+def basic_structure(text, master):
+    e = etree.fromstring('''<utwor>
+<master>
+<!--%s--><!--%s-->
+</master>
+</utwor>''' % (TRIM_BEGIN, TRIM_END))
+    e[0].tag = master
+    e[0][0].tail = "\n"*3 + text + "\n"*3
+    return etree.tostring(e, encoding="utf-8")
+
+
+def add_trim_begin(text):
+    trim_tag = etree.Comment(TRIM_BEGIN)
+    e = etree.fromstring(text)
+    for master in e[::-1]:
+        if master.tag in MASTERS:
+            break
+    if master.tag not in MASTERS:
+        raise ParseError('No master tag found!')
+
+    master.insert(0, trim_tag)
+    trim_tag.tail = '\n\n\n' + (master.text or '')
+    master.text = '\n'
+    return etree.tostring(e, encoding="utf-8")
+
+
+def add_trim_end(text):
+    trim_tag = etree.Comment(TRIM_END)
+    e = etree.fromstring(text)
+    for master in e[::-1]:
+        if master.tag in MASTERS:
+            break
+    if master.tag not in MASTERS:
+        raise ParseError('No master tag found!')
+
+    master.append(trim_tag)
+    trim_tag.tail = '\n'
+    prev = trim_tag.getprevious()
+    if prev is not None:
+        prev.tail = (prev.tail or '') + '\n\n\n'
+    else:
+        master.text = (master.text or '') + '\n\n\n'
+    return etree.tostring(e, encoding="utf-8")