The Refresh product.

doc/CHANGES.txt

@@ -57,6 +57,10 @@ Zope changes
         - DTML-In and DTML-Tree now have optional "prefix" attributes
           that can be used to make friendlier tag variable names.
 
+        - Added product reloading capability, formerly provided by
+          the "Refresh" product.  This enables developers to see the
+          effect of changes to their products without restarting Zope.
+
     Zope 2.3.0 beta 3
 
       Features Added

lib/python/App/Product.py

@@ -116,6 +116,7 @@ from Factory import Factory
 from Permission import PermissionManager
 import ZClasses, ZClasses.ZClass
 from HelpSys.HelpSys import ProductHelp
+import RefreshFuncs
 
 
 class ProductFolder(Folder):
@@ -341,6 +342,129 @@ class Product(Folder, PermissionManager):
             self._setObject('Help', ProductHelp('Help', self.id))
         return self.Help
 
+    #
+    # Product refresh
+    #
+
+    _refresh_dtml = Globals.DTMLFile('dtml/refresh', globals())
+
+    def _readRefreshTxt(self, pid=None):
+        refresh_txt = None
+        if pid is None:
+            pid = self.id
+        for productDir in Products.__path__:
+            found = 0
+            for name in ('refresh.txt', 'REFRESH.txt', 'REFRESH.TXT'):
+                p = os.path.join(productDir, pid, name)
+                if os.path.exists(p):
+                    found = 1
+                    break
+            if found:
+                try:
+                    file = open(p)
+                    text = file.read()
+                    file.close()
+                    refresh_txt = text
+                    break
+                except:
+                    # Not found here.
+                    pass
+        return refresh_txt
+
+    def manage_refresh(self, REQUEST, manage_tabs_message=None):
+        '''
+        Displays the refresh management screen.
+        '''
+        error_type = error_value = error_tb = None
+        exc = RefreshFuncs.getLastRefreshException(self.id)
+        if exc is not None:
+            error_type, error_value, error_tb = exc
+            exc = None
+
+        refresh_txt = self._readRefreshTxt()
+
+        # Read the persistent refresh information.
+        auto = RefreshFuncs.isAutoRefreshEnabled(self._p_jar, self.id)
+        deps = RefreshFuncs.getDependentProducts(self._p_jar, self.id)
+
+        # List all product modules.
+        mods = RefreshFuncs.listRefreshableModules(self.id)
+        loaded_modules = []
+        prefix = 'Products.%s' % self.id
+        prefixdot = prefix + '.'
+        lpdot = len(prefixdot)
+        for name, module in mods:
+            if name == prefix or name[:lpdot] == prefixdot:
+                name = name[lpdot:]
+                if not name:
+                    name = '__init__'
+            loaded_modules.append(name)
+
+        all_auto = RefreshFuncs.listAutoRefreshableProducts(self._p_jar)
+        for pid in all_auto:
+            # Ignore products that don't have a refresh.txt.
+            if self._readRefreshTxt(pid) is None:
+                all_auto.remove(pid)
+        auto_other = filter(lambda productId, myId=self.id:
+                            productId != myId, all_auto)
+
+        # Return rendered DTML.
+        return self._refresh_dtml(REQUEST,
+                                  id=self.id,
+                                  refresh_txt=refresh_txt,
+                                  error_type=error_type,
+                                  error_value=error_value,
+                                  error_tb=error_tb,
+                                  devel_mode=Globals.DevelopmentMode,
+                                  auto_refresh_enabled=auto,
+                                  auto_refresh_other=auto_other,
+                                  dependent_products=deps,
+                                  loaded_modules=loaded_modules,
+                                  manage_tabs_message=manage_tabs_message,
+                                  management_view='Refresh')
+
+    def manage_performRefresh(self, REQUEST=None):
+        '''
+        Attempts to perform a refresh operation.
+        '''
+        if self._readRefreshTxt() is None:
+            raise 'Unauthorized', 'refresh.txt not found'
+        message = None
+        if RefreshFuncs.performFullRefresh(self._p_jar, self.id):
+            from ZODB import Connection
+            Connection.updateCodeTimestamp() # Clears cache in next connection.
+            message = 'Product refreshed.'
+        else:
+            message = 'An exception occurred.'
+        if REQUEST is not None:
+            return self.manage_refresh(REQUEST, manage_tabs_message=message)
+
+    def manage_enableAutoRefresh(self, enable=0, REQUEST=None):
+        '''
+        Changes the auto refresh flag for this product.
+        '''
+        if self._readRefreshTxt() is None:
+            raise 'Unauthorized', 'refresh.txt not created'
+        RefreshFuncs.enableAutoRefresh(self._p_jar, self.id, enable)
+        if enable:
+            message = 'Enabled auto refresh.'
+        else:
+            message = 'Disabled auto refresh.'
+        if REQUEST is not None:
+            return self.manage_refresh(REQUEST, manage_tabs_message=message)
+
+    def manage_selectDependentProducts(self, selections=(), REQUEST=None):
+        '''
+        Selects which products to refresh simultaneously.
+        '''
+        if self._readRefreshTxt() is None:
+            raise 'Unauthorized', 'refresh.txt not created'
+        RefreshFuncs.setDependentProducts(self._p_jar, self.id, selections)
+        if REQUEST is not None:
+            return self.manage_refresh(REQUEST)
+
+
+
 class CompressedOutputFile:
     def __init__(self, rot):
         self._c=zlib.compressobj()
@@ -477,6 +601,17 @@ def initializeProduct(productp, name, home, app):
                 )
             break
 
+    # Ensure this product has a refresh tab.
+    found = 0
+    for option in product.manage_options:
+        if option.get('label') == 'Refresh':
+            found = 1
+            break
+    if not found:
+        product.manage_options = product.manage_options + (
+            {'label':'Refresh', 'action':'manage_refresh',
+             'help': ('OFSP','Product_Refresh.stx')},)
+
     if (os.environ.get('ZEO_CLIENT') and
         not os.environ.get('FORCE_PRODUCT_LOAD')):
         get_transaction().abort()

lib/python/App/dtml/refresh.dtml

+<dtml-comment>
+  Arguments for this method:
+   id, refresh_txt, error_type, error_value, error_tb, devel_mode,
+   auto_refresh_enabled, auto_refresh_other, dependent_products,
+   loaded_modules
+</dtml-comment>
+<dtml-let form_title="'Refresh product: ' + id">
+<dtml-if manage_page_header>
+ <dtml-var manage_page_header>
+<dtml-else>
+ <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
+ <html lang="en">
+ <head>
+ <title>&dtml-form_title;</title>
+ </head>
+ <body bgcolor="#FFFFFF" link="#000099" vlink="#555555">
+ <h3>&dtml-form_title;</h3>
+</dtml-if>
+</dtml-let>
+<dtml-var manage_tabs>
+
+<dtml-if expr="refresh_txt == _.None">
+ <p>The refresh function, designed to ease the development of Zope
+ products, is not currently enabled for this product.
+ To make it available, put a file named "refresh.txt" in the &dtml-id;
+ product directory.  Please note that not all products are
+ compatible with the refresh function.</p>
+<dtml-else>
+
+ <dtml-if error_type>
+  <p><b>An exception occurred during the last refresh.</b><br />
+   Exception type: <b>&dtml-error_type;</b> <br />
+   Exception value: <b>&dtml-error_value;</b>
+  </p>
+  <pre>&dtml-error_tb;</pre>
+  <hr />
+ </dtml-if>
+
+ <form action="&dtml-absolute_url;" method="POST">
+  <table border="0">
+   <tr>
+    <td valign="top">
+
+     <dtml-if expr="_.string.strip(refresh_txt)">
+      <p>
+       <b>Important information about refreshing this product:</b><br />
+       <dtml-var refresh_txt fmt="structured-text">
+      </p>
+     </dtml-if>
+
+     <div align="center"><input type="submit"
+         name="manage_performRefresh:method" value="Refresh this product" />
+     </div>
+
+     <p>
+      <dtml-if auto_refresh_enabled>
+       <dtml-if devel_mode>
+       Auto refresh is enabled.  Zope will repeatedly scan for
+       changes to the Python modules that make up this product and
+       execute a refresh when needed.
+       <dtml-else>
+       Although auto refresh is enabled, Zope is not in development
+       mode so auto refresh is not available.  Use the "-D" argument
+       when starting Zope to enable development mode.
+       </dtml-if>
+      <dtml-else>
+       Auto refresh is disabled.  Enable auto refresh
+       to cause Zope to frequently scan this product for changes.
+       Note that auto refresh can slow down Zope considerably
+       if enabled for more than a few products.
+      </dtml-if>
+      <br />
+      <dtml-let checked="auto_refresh_enabled and 'checked' or ' '">
+       <input type="checkbox" name="enable" value="1" &dtml-checked; />
+       Auto refresh mode &nbsp;
+       <input type="submit" name="manage_enableAutoRefresh:method"
+              value="Change" />
+      </dtml-let>
+     </p>
+
+     <dtml-if auto_refresh_other>
+      <p>Select dependent auto-refreshable products to be refreshed
+      simultaneously.<br />
+      <dtml-in auto_refresh_other sort>
+       <dtml-let checked="(_['sequence-item'] in dependent_products) and
+         'checked' or ' '">
+        <input type="checkbox" name="selections:list"
+         value="&dtml-sequence-item;" &dtml-checked; />
+        <a href="../&dtml-sequence-item;/manage_refresh"
+         >&dtml-sequence-item;</a><br />
+       </dtml-let>
+      </dtml-in>
+      <input type="submit" name="manage_selectDependentProducts:method"
+       value="Change" />
+      </p>
+     </dtml-if>
+
+    </td>
+    <td valign="top" class="row-hilite">
+
+     <p><b>Refreshable product modules:</b></p>
+     <ul>
+      <dtml-in loaded_modules sort>
+       <li>&dtml-sequence-item;</li>
+      </dtml-in>
+     </ul>
+
+    </td>
+   </tr>
+  </table>
+ </form>
+</dtml-if>
+
+<dtml-if manage_page_footer>
+  <dtml-var manage_page_footer>
+<dtml-else>
+  </body></html>
+</dtml-if>

lib/python/OFS/Application.py

@@ -85,8 +85,8 @@
 __doc__='''Application support
 
 
-$Id: Application.py,v 1.143 2001/04/07 16:37:07 jim Exp $'''
-__version__='$Revision: 1.143 $'[11:-2]
+$Id: Application.py,v 1.144 2001/05/17 18:35:09 shane Exp $'''
+__version__='$Revision: 1.144 $'[11:-2]
 
 import Globals,Folder,os,sys,App.Product, App.ProductRegistry, misc_
 import time, traceback, os, string, Products
@@ -495,16 +495,8 @@ def initialize(app):
                 get_transaction().abort()
 
 
-def import_products(_st=type('')):
+def import_products():
     # Try to import each product, checking for and catching errors.
-    path_join=os.path.join
-    isdir=os.path.isdir
-    exists=os.path.exists
-    DictType=type({})
-    global_dict=globals()
-    silly=('__doc__',)
-    modules=sys.modules
-    have_module=modules.has_key
     done={}
 
     for product_dir in Products.__path__:
@@ -516,12 +508,26 @@ def import_products(_st=type('')):
 
             if done.has_key(product_name): continue
             done[product_name]=1
+            import_product(product_dir, product_name)
+
 
+def import_product(product_dir, product_name, raise_exc=0, log_exc=1):
+    path_join=os.path.join
+    isdir=os.path.isdir
+    exists=os.path.exists
+    _st=type('')
+    global_dict=globals()
+    silly=('__doc__',)
+    modules=sys.modules
+    have_module=modules.has_key
+
+    if 1:  # Preserve indentation for diff :-)
+        try:
             package_dir=path_join(product_dir, product_name)
-            if not isdir(package_dir): continue
+            if not isdir(package_dir): return
             if not exists(path_join(package_dir, '__init__.py')):
                 if not exists(path_join(package_dir, '__init__.pyc')):
-                    continue
+                    return
 
             pname="Products.%s" % product_name
             try:
@@ -532,35 +538,27 @@ def import_products(_st=type('')):
                             if type(v) is _st and have_module(v): v=modules[v]
                             modules[k]=v
             except:
-                LOG('Zope',ERROR,'Couldn\'t import %s' % pname,
-                    error=sys.exc_info())
+                exc = sys.exc_info()
+                if log_exc:
+                    LOG('Zope', ERROR, 'Could not import %s' % pname,
+                        error=exc)
                 f=StringIO()
                 traceback.print_exc(100,f)
                 f=f.getvalue()
                 try: modules[pname].__import_error__=f
                 except: pass
+                if raise_exc:
+                    raise exc[0], exc[1], exc[2]
+        finally:
+            exc = None
 
 
 def install_products(app):
     # Install a list of products into the basic folder class, so
     # that all folders know about top-level objects, aka products
 
-    path_join=os.path.join
-    isdir=os.path.isdir
-    exists=os.path.exists
-    DictType=type({})
-
-    from Folder import Folder
-    folder_permissions={}
-    for p in Folder.__ac_permissions__:
-        permission, names = p[:2]
-        folder_permissions[permission]=names
-
+    folder_permissions = get_folder_permissions()
     meta_types=[]
-
-    global_dict=globals()
-    silly=('__doc__',)
-
     done={}
 
     get_transaction().note('Prior to product installs')
@@ -579,13 +577,38 @@ def install_products(app):
             if done.has_key(product_name):
                 continue
             done[product_name]=1
+            install_product(app, product_dir, product_name, meta_types,
+                            folder_permissions)
+
+    Products.meta_types=Products.meta_types+tuple(meta_types)
+    Globals.default__class_init__(Folder.Folder)
+
+
+def get_folder_permissions():
+    folder_permissions={}
+    for p in Folder.Folder.__ac_permissions__:
+        permission, names = p[:2]
+        folder_permissions[permission]=names
+    return folder_permissions
+
+
+def install_product(app, product_dir, product_name, meta_types,
+                    folder_permissions, raise_exc=0, log_exc=1):
+
+    path_join=os.path.join
+    isdir=os.path.isdir
+    exists=os.path.exists
+    DictType=type({})
+    global_dict=globals()
+    silly=('__doc__',)
 
+    if 1:  # Preserve indentation for diff :-)
             package_dir=path_join(product_dir, product_name)
             __traceback_info__=product_name
-            if not isdir(package_dir): continue
+            if not isdir(package_dir): return
             if not exists(path_join(package_dir, '__init__.py')):
                 if not exists(path_join(package_dir, '__init__.pyc')):
-                    continue
+                    return
             try:
                 product=__import__("Products.%s" % product_name,
                                    global_dict, global_dict, silly)
@@ -661,8 +684,8 @@ def install_products(app):
                     for permission, names in new_permissions:
                         folder_permissions[permission]=names
                     new_permissions.sort()
-                    Folder.__dict__['__ac_permissions__']=tuple(
-                        list(Folder.__ac_permissions__)+new_permissions)
+                    Folder.Folder.__dict__['__ac_permissions__']=tuple(
+                        list(Folder.Folder.__ac_permissions__)+new_permissions)
 
                 if (os.environ.get('ZEO_CLIENT') and
                     not os.environ.get('FORCE_PRODUCT_LOAD')):
@@ -674,13 +697,58 @@ def install_products(app):
                     get_transaction().commit()
 
             except:
+                if log_exc:
                     LOG('Zope',ERROR,'Couldn\'t install %s' % product_name,
                         error=sys.exc_info())
                 get_transaction().abort()
+                if raise_exc:
+                    raise
+
+
+def reinstall_product(app, product_name):
+    folder_permissions = get_folder_permissions()
+    meta_types=[]
+
+    get_transaction().note('Prior to product reinstall')
+    get_transaction().commit()
+
+    for product_dir in Products.__path__:
+        product_names=os.listdir(product_dir)
+        product_names.sort()
+        if product_name in product_names:
+            removeProductMetaTypes(product_name)
+            install_product(app, product_dir, product_name, meta_types,
+                            folder_permissions, raise_exc=1, log_exc=0)
 
     Products.meta_types=Products.meta_types+tuple(meta_types)
+    Globals.default__class_init__(Folder.Folder)
+
 
-    Globals.default__class_init__(Folder)
+def reimport_product(product_name):
+    for product_dir in Products.__path__:
+        product_names=os.listdir(product_dir)
+        product_names.sort()
+        if product_name in product_names:
+            import_product(product_dir, product_name,
+                           raise_exc=1, log_exc=0)
+            break
+
+
+def removeProductMetaTypes(pid):
+    '''
+    Unregisters the meta types registered by a product.
+    '''
+    meta_types = Products.meta_types
+    new_mts = []
+    changed = 0
+    for meta_type in meta_types:
+        if meta_type.get('product', None) == pid:
+            # Remove this meta type.
+            changed = 1
+        else:
+            new_mts.append(meta_type)
+    if changed:
+        Products.meta_types = tuple(new_mts)
 
 
 def pgetattr(product, name, default=install_products, __init__=0):

lib/python/Products/OFSP/help/Product_Refresh.stx

+Product - Refresh: Reload a filesystem-based Python product.
+  
+  Description
+
+    This view allows you to reload filesystem-based product code
+    without restarting Zope.  This function is useful during
+    development of products.
+
+    To enable your product to be refreshed, it is required that you
+    put a file called 'refresh.txt' in your product directory.
+    It can optionally contain a warning for others who might use
+    the refresh function.
+
+    (Producting refreshing is not perfect.  Some products, especially
+    "hotfix" style products which patch Zope, should not be refreshed.
+    That's why 'refresh.txt' is required.  Most products are safe to
+    refresh, however.)
+
+    There are two modes of operation.  You can visit your product's
+    'Refresh' tab and manually push the refresh button.  Or you can
+    turn on "auto-refresh" mode, which causes Zope to periodically
+    scan the modification time of the Python files that make up your
+    product and execute a refresh operation in the background.
+
+    **NOTE**: Don't enable auto-refresh for too many products at once.
+    Scanning file modification times can take a lot of time per
+    request.
+
+    You can also select dependent refreshable products.  If you have
+    a product that subclasses from a product you're working on,
+    you'll want to enable refresh for both products and add the
+    product that subclasses as a dependent of the product you're
+    modifying.  This enables subclasses to be updated.
+
+  Controls
+
+    'Refresh this product' -- The manual refresh button.
+
+    'Auto refresh mode' -- Check the checkbox to enable auto-refresh.
+
+    'Dependent auto-refreshable products' -- A list of other products
+    which are auto-refreshable.
+
+  How it works
+
+    To execute a refresh, Zope looks in the sys.modules dictionary
+    for modules with names that start with the prefix for your product.
+    It tries to scan for dependencies between the modules that make
+    up your product then uses Python's reload() function for each
+    module in order.  Then it sets a flag that will cause ZODB to dump
+    its cache on the next connection so that changes to persistent
+    classes will take effect.
+
+    To implement auto-refresh, Zope stores a PersistentMapping called
+    RefreshData on the database root object (below the Application
+    object).  The contents of the PersistentMapping are examined at the
+    moment a database connection is opened by ZApplication.  The
+    PersistentMapping contains a list of which products have auto-refresh
+    enabled.  For each product with auto-refresh enabled, Zope compares
+    the file mod times with the last recorded times and executes a
+    refresh if there are any changes.
+

lib/python/Zope/__init__.py

@@ -142,13 +142,18 @@ app=bobo_application=ZODB.ZApplication.ZApplicationWrapper(
 # Initialize products:
 c=app()
 OFS.Application.initialize(c)
+
+if Globals.DevelopmentMode:
+    # Set up auto-refresh.
+    from App.RefreshFuncs import setupAutoRefresh
+    setupAutoRefresh(c._p_jar)
+
 c._p_jar.close()
 del c
 
 # "Log off" as system user
 AccessControl.SecurityManagement.noSecurityManager()
 
-
 # This is sneaky, but we don't want to play with Main:
 sys.modules['Main']=sys.modules['Zope']