Merge lp:~chromakode/boots/boots_pager into lp:~cboylan/boots/boots_pager

[Max Goodhart]

[lp:~chromakode/boots/boots_pager]

101. By Max Goodhart on 2010-03-01

Fix handling of IOError in pager invocation.

=== modified file 'boots/app/client_config.py'
--- boots/app/client_config.py	2010-02-28 21:48:22 +0000
+++ boots/app/client_config.py	2010-03-01 08:21:16 +0000
@@ -26,9 +26,31 @@
 options/arguments."""
 
 import optparse
-import os
+import os, os.path
 import info
 
+def find_executable(name):
+    # Search algorithm adapted from os._execvpe 
+    head, tail = os.path.split(name)
+    if head and os.path.exists(name):
+        return name
+    else:
+        if 'PATH' in os.environ:
+            envpath = os.environ['PATH']
+        else:
+            envpath = os.defpath
+        PATH = envpath.split(os.pathsep)
+        for dir in PATH:
+            fullname = os.path.join(dir, name)
+            if os.path.exists(fullname):
+                return fullname
+
+def get_auto_pager():
+    if find_executable("less"):
+        return "less -XF"
+    elif find_executable("more"):
+        return "more"    
+
 class ClientConfig(object):
     """Class used to read client configuration from files and the cli."""
 
@@ -50,6 +72,7 @@
                           "prompt1":            "> ",
                           "prompt2":            "+ ",
                           "pager":              None,
+                          "pager_command":      None,
                           "terminating_char":   ";",
                           "history_length":     100,
                           "history_file":       os.path.expanduser("~/.boots_history")}
@@ -160,6 +183,14 @@
         
         self._dict.update(from_file)
         self._dict.update(from_cli)
+        self._interpret_options()
+ 
+    def _interpret_options(self):
+        # Interpret options
+        if self["pager"] == "auto":
+            self["pager_command"] = get_auto_pager()
+        elif self["pager"]:
+            self["pager_command"] = self["pager"]
 
     def get_file_conf(self, filepath):
         """Read a configuration from the specified file. Return a dict."""
 
=== modified file 'boots/lib/ui/plain.py'
--- boots/lib/ui/plain.py	2010-03-01 07:07:41 +0000
+++ boots/lib/ui/plain.py	2010-03-01 08:21:16 +0000
@@ -61,10 +61,7 @@
         self.prompt2 = console.config["prompt2"]
         self.hist_file = console.config["history_file"]
         self.lingo = console.config["lingo"]
-        if console.config["pager"] == "auto":
-            self.pager = "less -FX"
-        else:
-            self.pager = console.config["pager"]
+        self.pager_command = console.config["pager_command"]
         self.last_desc = None
         self.buffer = []
         
@@ -129,6 +126,25 @@
             self.prompt1 = prompt1
             self.prompt2 = prompt2
 
+    def print_with_pager(self, text):
+        try:
+            pager = subprocess.Popen(self.pager_command.split(),
+                                     shell=False,
+                                     stdin=subprocess.PIPE)
+        except:
+            sys.stdout.write("Unable to run pager command \"{0}\". Pager disabled.\n"
+                             .format(self.pager_command))
+            self.pager_command = None
+            return False
+            
+        try:
+            pager.communicate(text)
+        except IOError:
+            # IOError is raised sometimes with large outputs
+            pass
+        
+        return True
+
     def present(self, result):
         """Print the result provided as an argument.
 
@@ -167,17 +183,16 @@
             self.last_desc = result["info"]
             if result["result"]:
                 self.buffer.extend(result["result"])
-            elif self.buffer and self.pager is None:
-                for row in _gen_table():
-                    sys.stdout.write(row)
-                # Reset values for next result set.
-                self.buffer = []
-            elif self.buffer and self.pager is not None and self.console.driver.is_interactive:
-                pager = subprocess.Popen(self.pager.split(), shell=False, stdin=subprocess.PIPE)
-                try:
-                    pager.communicate("".join(_gen_table()))
-                except IOError:
-                    pass
+            elif self.buffer:
+                printed = False
+                if self.pager_command and self.console.driver.is_interactive:
+                    printed = self.print_with_pager("".join(_gen_table()))
+                
+                # Fallback if no pager set, or paging fails.
+                if not printed:
+                    for row in _gen_table():
+                        sys.stdout.write(row)
+                    
                 # Reset values for next result set.
                 self.buffer = []
         elif isinstance(result, Exception):