From dacfba330ce8dcafd68b2e8a60463e42a71cf180 Mon Sep 17 00:00:00 2001
From: Vangelis Banos <vangelis@archive.org>
Date: Thu, 4 Jan 2018 17:37:02 +0000
Subject: [PATCH] Configurable JS templates location

Brozzler has hard-coded the JS templates logic in  ``brozzler/behaviors.yaml``
and ``brozzler/js-templates/`` locations. With this change, you can use
the optional ``behaviors_dir`` ``browser.browse_page`` parameter to set a
custom location and use any potential JS behaviors.
---
 brozzler/__init__.py | 29 +++++++++++++++++++----------
 brozzler/browser.py  |  7 +++++--
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/brozzler/__init__.py b/brozzler/__init__.py
index 1c410ab..46ebf29 100644
--- a/brozzler/__init__.py
+++ b/brozzler/__init__.py
@@ -68,29 +68,34 @@ logging._levelToName[TRACE] = 'TRACE'
 logging._nameToLevel['TRACE'] = TRACE
 
 _behaviors = None
-def behaviors():
+def behaviors(behaviors_dir=None):
+    """Return list of JS behaviors loaded from YAML file.
+
+    :param behaviors_dir: Directory containing `behaviors.yaml` and
+    `js-templates/`. Defaults to brozzler dir.
+    """
     import os, yaml, string
     global _behaviors
     if _behaviors is None:
-        behaviors_yaml = os.path.join(
-                os.path.dirname(__file__), 'behaviors.yaml')
+        cwd = behaviors_dir or os.path.dirname(__file__)
+        behaviors_yaml = os.path.join(cwd, 'behaviors.yaml')
         with open(behaviors_yaml) as fin:
             _behaviors = yaml.load(fin)
     return _behaviors
 
-def behavior_script(url, template_parameters=None):
+def behavior_script(url, template_parameters=None, behaviors_dir=None):
     '''
     Returns the javascript behavior string populated with template_parameters.
     '''
     import re, logging
-    for behavior in behaviors():
+    for behavior in behaviors(behaviors_dir=behaviors_dir):
         if re.match(behavior['url_regex'], url):
             parameters = dict()
             if 'default_parameters' in behavior:
                 parameters.update(behavior['default_parameters'])
             if template_parameters:
                 parameters.update(template_parameters)
-            template = jinja2_environment().get_template(
+            template = jinja2_environment(behaviors_dir).get_template(
                     behavior['behavior_js_template'])
             script = template.render(parameters)
             logging.info(
@@ -229,12 +234,16 @@ def sleep(duration):
         time.sleep(min(duration - elapsed, 0.5))
 
 _jinja2_env = None
-def jinja2_environment():
+def jinja2_environment(behaviors_dir=None):
     global _jinja2_env
     if not _jinja2_env:
-        import jinja2, json
-        _jinja2_env = jinja2.Environment(
-                loader=jinja2.PackageLoader('brozzler', 'js-templates'))
+        import os, jinja2, json
+        if behaviors_dir:
+            _loader = jinja2.FileSystemLoader(os.path.join(behaviors_dir,
+                                                           'js-templates'))
+        else:
+            _loader=jinja2.PackageLoader('brozzler', 'js-templates')
+        _jinja2_env = jinja2.Environment(loader=_loader)
         _jinja2_env.filters['json'] = json.dumps
     return _jinja2_env
 
diff --git a/brozzler/browser.py b/brozzler/browser.py
index e827edf..66691ee 100644
--- a/brozzler/browser.py
+++ b/brozzler/browser.py
@@ -377,7 +377,7 @@ class Browser:
 
     def browse_page(
             self, page_url, extra_headers=None,
-            user_agent=None, behavior_parameters=None,
+            user_agent=None, behavior_parameters=None, behaviors_dir=None,
             on_request=None, on_response=None, on_screenshot=None,
             username=None, password=None, hashtags=None,
             skip_extract_outlinks=False, skip_visit_hashtags=False,
@@ -397,6 +397,8 @@ class Browser:
                 supplied (default None)
             behavior_parameters: dict of parameters for populating the
                 javascript behavior template (default None)
+            behaviors_dir: Directory containing behaviors.yaml and JS templates
+                (default None loads Brozzler default JS behaviors)
             on_request: callback to invoke on every Network.requestWillBeSent
                 event, takes one argument, the json-decoded message (default
                 None)
@@ -447,7 +449,8 @@ class Browser:
                     jpeg_bytes = self.screenshot()
                     on_screenshot(jpeg_bytes)
                 behavior_script = brozzler.behavior_script(
-                        page_url, behavior_parameters)
+                        page_url, behavior_parameters,
+                        behaviors_dir=behaviors_dir)
                 self.run_behavior(behavior_script, timeout=behavior_timeout)
                 if skip_extract_outlinks:
                     outlinks = []