Add new header type "Preset Header"

As first envisioned in #69, these preset headers allow us to have a
hierarchical structure of taskwarrior filters and defaults.

taskwiki/cache.py

@@ -2,6 +2,7 @@ import vim  # pylint: disable=F0401
 import re
 import six
 
+from taskwiki import preset
 from taskwiki import viewport
 from taskwiki import regexp
 from taskwiki import store
@@ -115,6 +116,7 @@ class TaskCache(object):
 
         self.buffer = BufferProxy(buffer_number)
         self.task = store.TaskStore(self)
+        self.presets = store.PresetStore(self)
         self.vwtask = store.VwtaskStore(self)
         self.viewport = store.ViewportStore(self)
         self.line = store.LineStore(self)
@@ -143,6 +145,23 @@ class TaskCache(object):
         self.viewport.store = dict()
         self.line.store = dict()
 
+    def load_presets(self):
+        stack = []
+
+        for i in range(len(self.buffer)):
+            header = preset.PresetHeader.from_line(i, self, stack[-1] if stack else None)
+
+            if header is None:
+                continue
+
+            # Save the preset header in the cache
+            self.presets[i] = header
+
+            while stack and stack[-1].level >= header.level:
+                stack.pop()
+
+            stack.append(header)
+
     def load_vwtasks(self, buffer_has_authority=True):
         # Set the authority flag, which determines which data (Buffer or TW)
         # will be considered authoritative

taskwiki/main.py

@@ -35,6 +35,7 @@ class WholeBuffer(object):
         c = cache()
         c.reset()
         c.load_tasks()
+        c.load_presets()
         c.load_vwtasks(buffer_has_authority=False)
         c.load_viewports()
         c.update_vwtasks_from_tasks()
@@ -53,6 +54,7 @@ class WholeBuffer(object):
         c = cache()
         c.reset()
         c.load_tasks()
+        c.load_presets()
         c.load_vwtasks()
         c.load_viewports()
         c.save_tasks()

taskwiki/preset.py

@@ -0,0 +1,96 @@
+import re
+import six
+
+from taskwiki import regexp
+from taskwiki import util
+
+class PresetHeader(object):
+    """
+        == Taskwiki tasks || project:taskwiki ==
+    """
+
+    def __init__(self, cache, parent, level, filterstring, defaultstring):
+
+        self.level = level
+        self.parent = parent
+
+        if parent:
+            taskfilter = list(parent.taskfilter)
+        else:
+            taskfilter = []
+
+        if filterstring:
+            taskfilter += '('
+            taskfilter += util.tw_modstring_to_args(filterstring)
+            taskfilter += ')'
+
+        self.taskfilter = taskfilter
+
+
+        if parent:
+            defaults = dict(parent.defaults)
+        else:
+            defaults = dict()
+
+        if defaultstring:
+            defaults.update(util.tw_modstring_to_kwargs(defaultstring))
+        else:
+            defaults.update(util.tw_args_to_kwargs(taskfilter))
+
+        self.defaults = defaults
+
+    @classmethod
+    def parse_line(cls, cache, number):
+        header = re.search(regexp.GENERIC_HEADER, cache.buffer[number])
+
+        if header:
+            preset = re.search(regexp.GENERIC_PRESET, cache.buffer[number])
+            if preset:
+                return preset
+
+        return header
+
+    @classmethod
+    def from_line(cls, number, cache, previous=None):
+        match = cache.line[(cls, number)]
+
+        if not match:
+            return None
+
+        level = len(match.group('header_start'))
+
+        if level == 1:
+            parent = None
+        else:
+            # Manually get previous header
+            if not previous:
+                for i in reversed(range(0, number)):
+                    previous = cls.from_line(i, cache)
+                    if previous:
+                        break
+
+            # find parent
+            parent = previous
+            while parent and parent.level >= level:
+                parent = parent.parent
+
+        if parent is None:
+            # Create an empty root stub
+            parent = cls(cache, None, 0, None, None)
+
+
+        # use parent object, if no additional filters / defaults are applied
+        try:
+            filterstring = match.group('filter')
+        except IndexError:
+            return parent
+
+
+        defaults = match.group('defaults')
+
+        if six.PY2:
+            filterstring = filterstring.decode('utf-8')
+            defaults = defaults.decode('utf-8') if defaults is not None else defaults
+
+        self = cls(cache, parent, level, filterstring, defaults)
+        return self

taskwiki/regexp.py

@@ -60,12 +60,27 @@ GENERIC_VIEWPORT = re.compile(
     '[=]+'                       # Header ending
     )
 
+GENERIC_PRESET = re.compile(
+    '^'                           # Starts at the beginning of the line
+    '(?P<header_start>[=]+)'      # With a positive number of =
+    '([^=\|\[\{]*)'               # Heading caption, everything up to ||
+                                  # Cannot include '[', '=', '|, and '{'
+    '\|\|'                        # Delimiter
+    '(?P<filter>[^=\|]+?)'        # Filter preset
+    '('                           # Optional defaults
+      '\|\|'                      # Delimiter
+      '(?P<defaults>[^=\|]+?)'    # Default attrs preset
+    ')?'
+    '\s*'                         # Any whitespace
+    '[=]+'                        # Header ending
+    )
+
 GENERIC_HEADER = re.compile(
-    '^'        # Starts at the beginning of the line
-    '[=]+'     # With a positive number of =
-    '[^=]+'    # Character other than =
-    '[=]+'     # Positive number of =, closing the header
-    '\s*'      # Allow trailing whitespace
+    '^'                      # Starts at the beginning of the line
+    '(?P<header_start>[=]+)' # With a positive number of =
+    '[^=]+'                  # Character other than =
+    '[=]+'                   # Positive number of =, closing the header
+    '\s*'                    # Allow trailing whitespace
 )
 
 ANSI_ESCAPE_SEQ = re.compile(

taskwiki/store.py

@@ -149,6 +149,13 @@ class ViewportStore(LineNumberedKeyedStoreMixin, NoNoneStore):
         return viewport.ViewPort.from_line(line, self.cache)
 
 
+class PresetStore(LineNumberedKeyedStoreMixin, NoNoneStore):
+
+    def get_method(self, line):
+        import preset
+        return preset.PresetHeader.from_line(line, self.cache)
+
+
 class LineStore(NoNoneStore):
 
     def __delitem__(self, number):

tests/test_preset_parsing.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+from tests.base import MockVim, MockCache
+import sys
+
+
+class TestParsingPresetHeader(object):
+    def setup(self):
+        self.mockvim = MockVim()
+        self.cache = MockCache()
+
+        sys.modules['vim'] = self.mockvim
+        from taskwiki.preset import PresetHeader
+        self.PresetHeader = PresetHeader
+
+    def teardown(self):
+        self.mockvim.reset()
+        self.cache.reset()
+
+    def test_simple(self):
+        self.cache.buffer[0] = "== Test || project:Home =="
+        header = self.PresetHeader.from_line(0, self.cache)
+
+        assert header.taskfilter == ["(", "project:Home", ")"]
+        assert header.defaults == {'project': 'Home'}
+
+    def test_defaults(self):
+        self.cache.buffer[0] = "== Test || project:Home || +home =="
+        header = self.PresetHeader.from_line(0, self.cache)
+
+        assert header.taskfilter == ["(", "project:Home", ")"]
+        assert header.defaults == {'tags': ['home']}