Templite: a lightweight template class to use when making HTML reports.

1 files changed, 81 insertions, 0 deletions

diff --git a/coverage/templite.py b/coverage/templite.py
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+"""A simple Python template renderer, for a nano-subset of Django syntax."""
+
+# Started from http://blog.ianbicking.org/templating-via-dict-wrappers.html
+# and http://jtauber.com/2006/05/templates.html
+# and http://code.activestate.com/recipes/496730/
+
+import re
+
+class Templite(object):
+    """A simple template renderer, for a nano-subset of Django syntax.
+    
+    """
+    def __init__(self, text, *contexts):
+        self.loops = []
+        self.text = self._prepare(text)
+        self.context = {}
+        for context in contexts:
+            self.context.update(context)
+
+    def render(self, context=None):
+        # Make the complete context we'll use.
+        ctx = dict(self.context)
+        if context:
+            ctx.update(context)
+            
+        ctxaccess = ContextAccess(ctx)
+        
+        # Render the loops.
+        for iloop, (loopvar, listvar, loopbody) in enumerate(self.loops):
+            result = ""
+            for listval in ctxaccess[listvar]:
+                ctx[loopvar] = listval
+                result += loopbody % ctxaccess
+            ctx["loop:%d" % iloop] = result
+            
+        # Render the final template.
+        return self.text % ctxaccess
+
+    def _prepare(self, text):
+        """Convert Django-style data references into Python-native ones."""
+        # Pull out loops.
+        text = re.sub(
+            r"{% for ([a-z0-9_]+) in ([a-z0-9_.|]+) %}(.*){% endfor %}",
+            self._loop_repl, text
+            )
+        # Protect actual percent signs in the text.
+        text = text.replace("%", "%%")
+        # Convert {{foo}} into %(foo)s
+        text = re.sub(r"{{([^}]+)}}", r"%(\1)s", text)
+        return text
+
+    def _loop_repl(self, match):
+        nloop = len(self.loops)
+        # Append (loopvar, listvar, loopbody) to self.loops
+        loopvar, listvar, loopbody = match.groups()
+        loopbody = self._prepare(loopbody)
+        self.loops.append((loopvar, listvar, loopbody))
+        return "{{loop:%d}}" % nloop
+
+
+class ContextAccess(object):
+    
+    def __init__(self, context):
+        self.context = context
+
+    def __getitem__(self, key):
+        if "|" in key:
+            pipes = key.split("|")
+            value = self[pipes[0]]
+            for func in pipes[1:]:
+                value = self[func](value)
+        elif "." in key:
+            dots = key.split('.') 
+            value = self[dots[0]]
+            for dot in dots[1:]:
+                value = getattr(value, dot)
+                if callable(value):
+                    value = value()
+        else:
+            value = self.context[key]
+        return value