Merge pull request #3 from kyleconroy/template

Add RFC6570 Uri Template Support

tests/test_template.py

@@ -0,0 +1,203 @@
+# encoding: utf-8
+from uricore import URI, IRI
+from nose.tools import eq_ 
+from uricore.template import uri_template
+from collections import OrderedDict
+
+# http://tools.ietf.org/html/rfc6570#section-3.2
+params = {
+    'count': ("one", "two", "three"),
+    'dom': ("example", "com"),
+    'dub': "me/too",
+    'hello': "Hello World!",
+    'half': "50%",
+    'var': "value",
+    'who': "fred",
+    'base': "http://example.com/home/",
+    'path': "/foo/bar",
+    'list': ("red", "green", "blue"),
+    'year': ("1965", "2000", "2012"),
+    'semi': ';',
+    'v': 6,
+    'x': 1024,
+    'y': 768,
+    'empty': "",
+    'empty_keys': [],
+    'undef': None,
+    'list': ["red", "green", "blue"],
+    'keys': OrderedDict([('semi', ";"), ('dot', "."), ('comma', ",")]),
+}
+
+def check_template(template, expansion):
+    eq_(uri_template(template, **params), expansion)
+
+
+def test_composite_values():
+    yield check_template, "find{?year*}", "find?year=1965&year=2000&year=2012"
+    yield check_template, "www{.dom*}", "www.example.com"
+
+
+def test_form_continuation_expansion():
+    yield check_template, "{&who}", "&who=fred"
+    yield check_template, "{&half}", "&half=50%25"
+    yield check_template, "?fixed=yes{&x}", "?fixed=yes&x=1024"
+    yield check_template, "{&x,y,empty}", "&x=1024&y=768&empty="
+    yield check_template, "{&x,y,undef}", "&x=1024&y=768"
+    yield check_template, "{&var:3}", "&var=val"
+    yield check_template, "{&list}", "&list=red,green,blue"
+    yield check_template, "{&list*}", "&list=red&list=green&list=blue"
+    yield check_template, "{&keys}", "&keys=semi,%3B,dot,.,comma,%2C"
+    yield check_template, "{&keys*}", "&semi=%3B&dot=.&comma=%2C"
+
+
+def test_form_style_expansion():
+    yield check_template, "{?who}", "?who=fred"
+    yield check_template, "{?half}", "?half=50%25"
+    yield check_template, "{?x,y}", "?x=1024&y=768"
+    yield check_template, "{?x,y,empty}", "?x=1024&y=768&empty="
+    yield check_template, "{?x,y,undef}", "?x=1024&y=768"
+    yield check_template, "{?var:3}", "?var=val"
+    yield check_template, "{?list}", "?list=red,green,blue"
+    yield check_template, "{?list*}", "?list=red&list=green&list=blue"
+    yield check_template, "{?keys}", "?keys=semi,%3B,dot,.,comma,%2C"
+    yield check_template, "{?keys*}", "?semi=%3B&dot=.&comma=%2C"
+
+
+def test_fragment_expansion():
+    yield check_template, "{#var}", "#value"
+    yield check_template, "{#hello}", "#Hello%20World!"
+    yield check_template, "{#half}", "#50%25"
+    yield check_template, "foo{#empty}", "foo#"
+    yield check_template, "foo{#undef}", "foo"
+    yield check_template, "{#x,hello,y}", "#1024,Hello%20World!,768"
+    yield check_template, "{#path,x}/here", "#/foo/bar,1024/here"
+    yield check_template, "{#path:6}/here", "#/foo/b/here"
+    yield check_template, "{#list}", "#red,green,blue"
+    yield check_template, "{#list*}", "#red,green,blue"
+    yield check_template, "{#keys}", "#semi,;,dot,.,comma,,"
+    yield check_template, "{#keys*}", "#semi=;,dot=.,comma=,"
+
+
+def test_label_expansion():
+    yield check_template, "{.who}", ".fred"
+    yield check_template, "{.who,who}", ".fred.fred"
+    yield check_template, "{.half,who}", ".50%25.fred"
+    yield check_template, "www{.dom*}", "www.example.com"
+    yield check_template, "X{.var}", "X.value"
+    yield check_template, "X{.empty}", "X."
+    yield check_template, "X{.undef}", "X"
+    yield check_template, "X{.var:3}", "X.val"
+    yield check_template, "X{.list}", "X.red,green,blue"
+    yield check_template, "X{.list*}", "X.red.green.blue"
+    yield check_template, "X{.keys}", "X.semi,%3B,dot,.,comma,%2C"
+    yield check_template, "X{.keys*}", "X.semi=%3B.dot=..comma=%2C"
+    yield check_template, "X{.empty_keys}", "X"
+    yield check_template, "X{.empty_keys*}", "X"
+
+
+def test_path_expansion():
+    yield check_template, "{/who}", "/fred"
+    yield check_template, "{/who,who}", "/fred/fred"
+    yield check_template, "{/half,who}", "/50%25/fred"
+    yield check_template, "{/who,dub}", "/fred/me%2Ftoo"
+    yield check_template, "{/var}", "/value"
+    yield check_template, "{/var,empty}", "/value/"
+    yield check_template, "{/var,undef}", "/value"
+    yield check_template, "{/var,x}/here", "/value/1024/here"
+    yield check_template, "{/var:1,var}", "/v/value"
+    yield check_template, "{/list}", "/red,green,blue"
+    yield check_template, "{/list*}", "/red/green/blue"
+    yield check_template, "{/list*,path:4}", "/red/green/blue/%2Ffoo"
+    yield check_template, "{/keys}", "/semi,%3B,dot,.,comma,%2C"
+    yield check_template, "{/keys*}", "/semi=%3B/dot=./comma=%2C"
+
+
+def test_path_style_expansion():
+    yield check_template, "{;who}", ";who=fred"
+    yield check_template, "{;half}", ";half=50%25"
+    yield check_template, "{;empty}", ";empty"
+    yield check_template, "{;v,empty,who}", ";v=6;empty;who=fred"
+    yield check_template, "{;v,bar,who}", ";v=6;who=fred"
+    yield check_template, "{;x,y}", ";x=1024;y=768"
+    yield check_template, "{;x,y,empty}", ";x=1024;y=768;empty"
+    yield check_template, "{;x,y,undef}", ";x=1024;y=768"
+    yield check_template, "{;hello:5}", ";hello=Hello"
+    yield check_template, "{;list}", ";list=red,green,blue"
+    yield check_template, "{;list*}", ";list=red;list=green;list=blue"
+    yield check_template, "{;keys}", ";keys=semi,%3B,dot,.,comma,%2C"
+    yield check_template, "{;keys*}", ";semi=%3B;dot=.;comma=%2C"
+
+
+def test_reserved_expansion():
+    yield check_template, "{+var}", "value"
+    yield check_template, "{+hello}", "Hello%20World!"
+    yield check_template, "{+half}", "50%25"
+    yield check_template, "{base}index", "http%3A%2F%2Fexample.com%2Fhome%2Findex"
+    yield check_template, "{+base}index", "http://example.com/home/index"
+    yield check_template, "O{+empty}X", "OX"
+    yield check_template, "O{+undef}X", "OX"
+    yield check_template, "{+path}/here", "/foo/bar/here"
+    yield check_template, "here?ref={+path}", "here?ref=/foo/bar"
+    yield check_template, "up{+path}{var}/here", "up/foo/barvalue/here"
+    yield check_template, "{+x,hello,y}", "1024,Hello%20World!,768"
+    yield check_template, "{+path,x}/here", "/foo/bar,1024/here"
+    yield check_template, "{+path:6}/here", "/foo/b/here"
+    yield check_template, "{+list}", "red,green,blue"
+    yield check_template, "{+list*}", "red,green,blue"
+    yield check_template, "{+keys}", "semi,;,dot,.,comma,,"
+    yield check_template, "{+keys*}", "semi=;,dot=.,comma=,"
+
+
+def test_simple_string_expansion():
+    yield check_template, "{var}", "value"
+    yield check_template, "{hello}", "Hello%20World%21"
+    yield check_template, "{half}", "50%25"
+    yield check_template, "O{empty}X", "OX"
+    yield check_template, "O{undef}X", "OX"
+    yield check_template, "{x,y}", "1024,768"
+    yield check_template, "{x,hello,y}", "1024,Hello%20World%21,768"
+    yield check_template, "?{x,empty}", "?1024,"
+    yield check_template, "?{x,undef}", "?1024"
+    yield check_template, "?{undef,y}", "?768"
+    yield check_template, "{var:3}", "val"
+    yield check_template, "{var:30}", "value"
+    yield check_template, "{list}", "red,green,blue"
+    yield check_template, "{list*}", "red,green,blue"
+    yield check_template, "{keys}", "semi,%3B,dot,.,comma,%2C"
+    yield check_template, "{keys*}", "semi=%3B,dot=.,comma=%2C"
+
+
+def test_test_prefix_values():
+    yield check_template, "{var}", "value"
+    yield check_template, "{var:20}", "value"
+    yield check_template, "{var:3}", "val"
+    yield check_template, "{semi}", "%3B"
+    yield check_template, "{semi:2}", "%3B"
+
+
+def test_variable_expansion():
+    yield check_template, "{count}", "one,two,three"
+    yield check_template, "{count*}", "one,two,three"
+    yield check_template, "{/count}", "/one,two,three"
+    yield check_template, "{/count*}", "/one/two/three"
+    yield check_template, "{;count}", ";count=one,two,three"
+    yield check_template, "{;count*}", ";count=one;count=two;count=three"
+    yield check_template, "{?count}", "?count=one,two,three"
+    yield check_template, "{?count*}", "?count=one&count=two&count=three"
+    yield check_template, "{&count*}", "&count=one&count=two&count=three"
+
+
+def test_composite_values():
+    yield check_template, "find{?year*}", "find?year=1965&year=2000&year=2012"
+    yield check_template, "www{.dom*}", "www.example.com"
+
+
+def test_uri_template():
+    eq_(URI("http://example.com/value"),
+        URI.from_template("http://example.com/{var}", var="value"))
+
+
+def test_iri_template():
+    eq_(IRI(u'http://\u2603/value'),
+        IRI.from_template(u'http://\N{SNOWMAN}/{var}', var='value'))
+

uricore/core.py

@@ -7,6 +7,7 @@
     import urllib.parse as urlparse
 
 from collections import defaultdict
+from template import uri_template
 
 # TODO: import these from httpcore someday
 from . import wkz_urls as urls
@@ -194,6 +195,11 @@ def join(self, other):
 
         return type(self)(unsplit(**vals), query_cls=self.query_cls)
 
+    @classmethod
+    def from_template(cls, template, **kwargs):
+        return cls(uri_template(template, **kwargs))
+
+
 
 class IRI(ResourceIdentifier):
 

uricore/template.py

@@ -0,0 +1,118 @@
+import re
+from . import wkz_urls as urls
+
+
+def _format_mapping(operator, item):
+    try:
+        k, v, mapped = item
+    except ValueError:
+        k, v = item
+        mapped = False
+
+    if operator in ['#', '+']:
+        # From http://tools.ietf.org/html/rfc6570#section-1.5
+        safe = ':/?#[]@!$&\'\"()*/+,;='
+    else:
+        safe = ''
+
+    if isinstance(v, (list, tuple)):
+        v = ','.join(urls.url_quote(x, safe=safe) for x in v)
+    else:
+        v = urls.url_quote(v, safe=safe)
+
+    if operator in [';', '?', '&'] or mapped:
+        if not v:
+            mid = '' if operator == ';' else '='
+        else:
+            mid = '='
+
+        return "{}{}{}".format(k, mid, v)
+    else:
+        return "{}".format(v)
+
+
+def _template_joiner(operator):
+    if operator in ['#', '+', '']:
+        return ','
+    elif operator == '?':
+        return '&'
+    elif operator == '.':
+        return'.'
+    return operator
+
+
+def _varspec_expansion(operator, varspec, data):
+    portion = None
+    explode = False
+
+    if ':' in varspec:
+        varspec, portion = varspec.split(':', 1)
+        portion = int(portion)
+
+    if varspec.endswith('*'):
+        varspec = varspec[:-1]
+        explode = True
+
+    value = data.get(varspec)
+
+    if value == None:
+        return []
+
+    try:
+        if len(value) == 0 and value != "":
+            return []
+    except TypeError:
+        pass
+
+    try:
+        if explode:
+            return [(k, v, True) for k,v in value.items()]
+        else:
+            parts = []
+            for k, v in value.items():
+                parts += [k, v]
+            return [(varspec, parts)]
+    except AttributeError:
+        pass
+
+    if isinstance(value, (list, tuple)):
+        if explode:
+            return [(varspec, v) for v in value]
+        else:
+            return [(varspec, value)]
+
+    value = unicode(value)
+
+    if portion is not None:
+        value = value[:portion]
+
+    return [(varspec, value)]
+
+
+def uri_template(template, **kwargs):
+
+    def template_expansion(matchobj):
+        varlist = matchobj.group(1)
+        operator = ''
+
+        if re.match(r"\+|#|\.|/|;|\?|&", varlist):
+            operator = varlist[0]
+            varlist = varlist[1:]
+
+        prefix = '' if operator == '+' else operator
+        joiner = _template_joiner(operator)
+
+        params = []
+        for varspec in varlist.split(','):
+            params += _varspec_expansion(operator, varspec, kwargs)
+
+        uri = [_format_mapping(operator, item) for item in params]
+
+        if not uri:
+            return ""
+
+        return prefix + joiner.join(uri)
+
+    return re.sub(r"{(.*?)}", template_expansion, template)
+
+