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<div class="document" id="upgrading-code-from-older-versions-of-quixote">
<h1 class="title">Upgrading code from older versions of Quixote</h1>
<p>This document lists backward-incompatible changes in Quixote, and
explains how to update application code to work with the newer
version.</p>
<div class="section" id="changes-from-1-0-to-2-0">
<h1><a name="changes-from-1-0-to-2-0">Changes from 1.0 to 2.0</a></h1>
<p>Change any imports you have from quixote.form to be from quixote.form1.</p>
<p>Change any imports you have from quixote.form2 to be from quixote.form.</p>
<p>Replace calls to HTTPRequest.get_form_var() with calls to get_field().</p>
<p>Define a create_publisher() function to get the publisher you need
and figure out how you want to connect it to web server.
See files in demo and server for examples.  Note that publish1.py
contains a publisher that works more like the Quixote1 Publisher,
and does not require the changes listed below.</p>
<p>Make every namespace be an instance of quixote.directory.Directory.
Update namespaces that are modules (or in the init.py of a package) by
defining a new class in the module that inherits from Directory and
moving your _q_exports and _q_* functions onto the class.  Replace
&quot;request&quot; parameters with &quot;self&quot; parameters on the new methods.  If
you have a _q_resolve method, include Resolving in the bases of your
new class.</p>
<p>Remove request from calls to _q_ functions.  If request, session,
user, path, or redirect is used in these new methods, replace as
needed with calls to get_request(), get_session(), get_user(),
get_path(), and/or redirect(), imported from quixote.</p>
<p>In every namespace that formerly traversed into a module, import the
new Directory class from the module and create an instance of the
Directory in a variable whose name is the name of the module.</p>
<p>In every namespace with a _q_exports and a _q_index, either add &quot;&quot; to
_q_exports or make sure that _q_lookup handles &quot;&quot; by returning the result
of a call to _q_index.</p>
<p>If your code depends on the Publisher's namespace_stack attribute,
try using quixote.util.get_directory_path() instead.  If you need the
namespace stack after the traversal, override Directory._q_traverse()
to call get_directory_path() when the end of the path is reached, and
record the result somewhere for later reference.</p>
<p>If your code depends on _q_exception_handler, override the _q_traverse
on your root namespace or on your own Directory class to catch exceptions
and handle them the way you want.  If you just want a general customization
for exception responses, you can change or override 
Publisher.format_publish_error().</p>
<p>If your code depended on _q_access, include the AccessControlled with
the bases of your Directory classes as needed.</p>
<p>Provide imports as needed to htmltext, TemplateIO, get_field,
get_request, get_session, get_user, get_path, redirect, ?.  You may
find dulcinea/bin/unknown.py useful for identifying missing imports.</p>
<p>Quixote 1's secure_errors configuration variable is not present in Quixote 2.</p>
<p>Form.__init__ no longer has name or attrs keywords.  If your existing
code calls Form.__init__ with 'attrs=foo', you'll need to change it to
'<a href="#id1" name="id2"><span class="problematic" id="id2">**</span></a>foo'.  Form instances no longer have a name attribute.  If your code
looks for form.name, you can find it with form.attrs.get('name').
The Form.__init__ keyword parameter (and attribute) 'action_url' is now 
named 'action'.</p>
<div class="system-message" id="id1">
<p class="system-message-title">System Message: <a name="id1">WARNING/2</a> (<tt>upgrading.txt</tt>, line 65); <em><a href="#id2">backlink</a></em></p>
Inline strong start-string without end-string.</div>
<p>The SessionPublisher class is gone.  Use the Publisher class instead.
Also, the 'session_mgr' keyword has been renamed to 'session_manager'.</p>
</div>
<div class="section" id="changes-from-0-6-1-to-1-0">
<h1><a name="changes-from-0-6-1-to-1-0">Changes from 0.6.1 to 1.0</a></h1>
<div class="section" id="sessions">
<h2><a name="sessions">Sessions</a></h2>
<p>A leading underscore was removed from the <tt class="literal"><span class="pre">Session</span></tt> attributes
<tt class="literal"><span class="pre">__remote_address</span></tt>, <tt class="literal"><span class="pre">__creation_time</span></tt>, and <tt class="literal"><span class="pre">__access_time</span></tt>.  If
you have pickled <tt class="literal"><span class="pre">Session</span></tt> objects you will need to upgrade them
somehow.  Our preferred method is to write a script that unpickles each
object, renames the attributes and then re-pickles it.</p>
</div>
</div>
<div class="section" id="changes-from-0-6-to-0-6-1">
<h1><a name="changes-from-0-6-to-0-6-1">Changes from 0.6 to 0.6.1</a></h1>
<div class="section" id="q-exception-handler-now-called-if-exception-while-traversing">
<h2><a name="q-exception-handler-now-called-if-exception-while-traversing"><tt class="literal"><span class="pre">_q_exception_handler</span></tt> now called if exception while traversing</a></h2>
<p><tt class="literal"><span class="pre">_q_exception_handler</span></tt> hooks will now be called if an exception is
raised during the traversal process.  Quixote 0.6 had a bug that caused
<tt class="literal"><span class="pre">_q_exception_handler</span></tt> hooks to only be called if an exception was
raised after the traversal completed.</p>
</div>
</div>
<div class="section" id="changes-from-0-5-to-0-6">
<h1><a name="changes-from-0-5-to-0-6">Changes from 0.5 to 0.6</a></h1>
<div class="section" id="q-getname-renamed-to-q-lookup">
<h2><a name="q-getname-renamed-to-q-lookup"><tt class="literal"><span class="pre">_q_getname</span></tt> renamed to <tt class="literal"><span class="pre">_q_lookup</span></tt></a></h2>
<p>The <tt class="literal"><span class="pre">_q_getname</span></tt> special function was renamed to <tt class="literal"><span class="pre">_q_lookup</span></tt>,
because that name gives a clearer impression of the function's
purpose.  In 0.6, <tt class="literal"><span class="pre">_q_getname</span></tt> still works but will trigger a
warning.</p>
</div>
<div class="section" id="form-framework-changes">
<h2><a name="form-framework-changes">Form Framework Changes</a></h2>
<p>The <tt class="literal"><span class="pre">quixote.form.form</span></tt> module was changed from a .ptl file to a .py
file.  You should delete or move the existing <tt class="literal"><span class="pre">quixote/</span></tt> directory
in <tt class="literal"><span class="pre">site-packages</span></tt> before running <tt class="literal"><span class="pre">setup.py</span></tt>, or at least delete
the old <tt class="literal"><span class="pre">form.ptl</span></tt> and <tt class="literal"><span class="pre">form.ptlc</span></tt> files.</p>
<p>The widget and form classes in the <tt class="literal"><span class="pre">quixote.form</span></tt> package now return
<tt class="literal"><span class="pre">htmltext</span></tt> instances.  Applications that use forms and widgets will
likely have to be changed to use the <tt class="literal"><span class="pre">[html]</span></tt> template type to avoid
over-escaping of HTML special characters.</p>
<p>Also, the constructor arguments to <tt class="literal"><span class="pre">SelectWidget</span></tt> and its subclasses have
changed.  This only affects applications that use the form framework
located in the <tt class="literal"><span class="pre">quixote.form</span></tt> package.</p>
<p>In Quixote 0.5, the <tt class="literal"><span class="pre">SelectWidget</span></tt> constructor had this signature:</p>
<pre class="literal-block">
def __init__ (self, name, value=None,
              allowed_values=None,
              descriptions=None,
              size=None,
              sort=0):
</pre>
<p><tt class="literal"><span class="pre">allowed_values</span></tt> was the list of objects that the user could choose,
and <tt class="literal"><span class="pre">descriptions</span></tt> was a list of strings that would actually be
shown to the user in the generated HTML.</p>
<p>In Quixote 0.6, the signature has changed slightly:</p>
<pre class="literal-block">
def __init__ (self, name, value=None,
              allowed_values=None,
              descriptions=None,
              options=None,
              size=None,
              sort=0):
</pre>
<p>The <tt class="literal"><span class="pre">quote</span></tt> argument is gone, and the <tt class="literal"><span class="pre">options</span></tt> argument has been 
added.  If an <tt class="literal"><span class="pre">options</span></tt> argument is provided, <tt class="literal"><span class="pre">allowed_values</span></tt> 
and <tt class="literal"><span class="pre">descriptions</span></tt> must not be supplied.</p>
<p>The <tt class="literal"><span class="pre">options</span></tt> argument, if present, must be a list of tuples with
1,2, or 3 elements, of the form <tt class="literal"><span class="pre">(value:any,</span> <span class="pre">description:any,</span>
<span class="pre">key:string)</span></tt>.</p>
<blockquote>
<ul class="simple">
<li><tt class="literal"><span class="pre">value</span></tt> is the object that will be returned if the user chooses 
this item, and must always be supplied.</li>
<li><tt class="literal"><span class="pre">description</span></tt> is a string or htmltext instance which will be
shown to the user in the generated HTML.  It will be passed
through the htmlescape() functions, so for an ordinary string
special characters such as '&amp;' will be converted to '&amp;amp;'.
htmltext instances will be left as they are.</li>
<li>If supplied, <tt class="literal"><span class="pre">key</span></tt> will be used in the value attribute 
of the option element (<tt class="literal"><span class="pre">&lt;option</span> <span class="pre">value=&quot;...&quot;&gt;</span></tt>).  
If not supplied, keys will be generated; <tt class="literal"><span class="pre">value</span></tt> is checked for a 
<tt class="literal"><span class="pre">_p_oid</span></tt> attribute and if present, that string is used; 
otherwise the description is used.</li>
</ul>
</blockquote>
<p>In the common case, most applications won't have to change anything,
though the ordering of selection items may change due to the
difference in how keys are generated.</p>
</div>
<div class="section" id="file-upload-changes">
<h2><a name="file-upload-changes">File Upload Changes</a></h2>
<p>Quixote 0.6 introduces new support for HTTP upload requests.  Any HTTP
request with a Content-Type of &quot;multipart/form-data&quot; -- which is
generally only used for uploads -- is now represented by
HTTPUploadRequest, a subclass of HTTPRequest, and the uploaded files
themselves are represented by Upload objects.</p>
<p>Whenever an HTTP request has a Content-Type of &quot;multipart/form-data&quot;,
an instance of HTTPUploadRequest is created instead of HTTPRequest.
Some of the fields in the request are presumably uploaded files and
might be quite large, so HTTPUploadRequest will read all of the fields
supplied in the request body and write them out to temporary files;
the temporary files are written in the directory specified by the
UPLOAD_DIR configuration variable.</p>
<p>Once the temporary files have been written, the HTTPUploadRequest
object is passed to a function or PTL template, just like an ordinary
request.  The difference between HTTPRequest and HTTPUploadRequest 
is that all of the form variables are represented as Upload objects.
Upload objects have three attributes:</p>
<dl>
<dt><tt class="literal"><span class="pre">orig_filename</span></tt></dt>
<dd>the filename supplied by the browser.</dd>
<dt><tt class="literal"><span class="pre">base_filename</span></tt></dt>
<dd>a stripped-down version of orig_filename with unsafe characters removed.
This could be used when writing uploaded data to a permanent location.</dd>
<dt><tt class="literal"><span class="pre">tmp_filename</span></tt></dt>
<dd>the path of the temporary file containing the uploaded data for this field.</dd>
</dl>
<p>Consult upload.txt for more information about handling file uploads.</p>
</div>
<div class="section" id="refactored-publisher-class">
<h2><a name="refactored-publisher-class">Refactored <cite>Publisher</cite> Class</a></h2>
<p>Various methods in the <cite>Publisher</cite> class were rearranged.  If your
application subclasses Publisher, you may need to change your code
accordingly.</p>
<blockquote>
<ul>
<li><p class="first"><tt class="literal"><span class="pre">parse_request()</span></tt> no longer creates the HTTPRequest object; 
instead a new method, <tt class="literal"><span class="pre">create_request()</span></tt>,  handles this, 
and can be overridden as required.</p>
<p>As a result, the method signature has changed from 
<tt class="literal"><span class="pre">parse_request(stdin,</span> <span class="pre">env)</span></tt> to <tt class="literal"><span class="pre">parse_request(request)</span></tt>.</p>
</li>
<li><p class="first">The <tt class="literal"><span class="pre">Publisher.publish()</span></tt> method now catches exceptions raised 
by <tt class="literal"><span class="pre">parse_request()</span></tt>.</p>
</li>
</ul>
</blockquote>
</div>
</div>
<div class="section" id="changes-from-0-4-to-0-5">
<h1><a name="changes-from-0-4-to-0-5">Changes from 0.4 to 0.5</a></h1>
<div class="section" id="session-management-changes">
<h2><a name="session-management-changes">Session Management Changes</a></h2>
<p>The Quixote session management interface underwent lots of change and
cleanup with Quixote 0.5.  It was previously undocumented (apart from
docstrings in the code), so we thought that this was a good opportunity
to clean up the interface.  Nevertheless, those brave souls who got
session management working just by reading the code are in for a bit of
suffering; this brief note should help clarify things.  The definitive
documentation for session management is session-mgmt.txt -- you should
start there.</p>
<div class="section" id="attribute-renamings-and-pickled-objects">
<h3><a name="attribute-renamings-and-pickled-objects">Attribute renamings and pickled objects</a></h3>
<p>Most attributes of the standard Session class were made private in order
to reduce collisions with subclasses.  The downside is that pickled
Session objects will break.  You might want to (temporarily) modify
session.py and add this method to Session:</p>
<pre class="literal-block">
def __setstate__ (self, dict):
    # Update for attribute renamings made in rev. 1.51.2.3
    # (between Quixote 0.4.7 and 0.5).
    self.__dict__.update(dict)
    if hasattr(self, 'remote_address'):
        self.__remote_address = self.remote_address
        del self.remote_address
    if hasattr(self, 'creation_time'):
        self.__creation_time = self.creation_time
        del self.creation_time
    if hasattr(self, 'access_time'):
        self.__access_time = self.access_time
        del self.access_time
    if hasattr(self, 'form_tokens'):
        self._form_tokens = self.form_tokens
        del self.form_tokens
</pre>
<p>However, if your sessions were pickled via ZODB, this may not work.  (It
didn't work for us.)  In that case, you'll have to add something like
this to your class that inherits from both ZODB's Persistent and
Quixote's Session:</p>
<pre class="literal-block">
def __setstate__ (self, dict):
    # Blechhh!  This doesn't work if I put it in Quixote's
    # session.py, so I have to second-guess how Python
    # treats &quot;__&quot; attribute names.
    self.__dict__.update(dict)
    if hasattr(self, 'remote_address'):
        self._Session__remote_address = self.remote_address
        del self.remote_address
    if hasattr(self, 'creation_time'):
        self._Session__creation_time = self.creation_time
        del self.creation_time
    if hasattr(self, 'access_time'):
        self._Session__access_time = self.access_time
        del self.access_time
    if hasattr(self, 'form_tokens'):
        self._form_tokens = self.form_tokens
        del self.form_tokens
</pre>
<p>It's not pretty, but it worked for us.</p>
</div>
<div class="section" id="cookie-domains-and-paths">
<h3><a name="cookie-domains-and-paths">Cookie domains and paths</a></h3>
<p>The session cookie config variables -- <tt class="literal"><span class="pre">COOKIE_NAME</span></tt>,
<tt class="literal"><span class="pre">COOKIE_DOMAIN</span></tt>, and <tt class="literal"><span class="pre">COOKIE_PATH</span></tt> -- have been renamed to
<tt class="literal"><span class="pre">SESSION_COOKIE_*</span></tt> for clarity.</p>
<p>If you previously set the config variable <tt class="literal"><span class="pre">COOKIE_DOMAIN</span></tt> to the name
of your server, this is most likely no longer necessary -- it's now fine
to leave <tt class="literal"><span class="pre">SESSION_COOKIE_DOMAIN</span></tt> unset (ie. <tt class="literal"><span class="pre">None</span></tt>), which
ultimately means browsers will only include the session cookie in
requests to the same server that sent it to them in the first place.</p>
<p>If you previously set <tt class="literal"><span class="pre">COOKIE_PATH</span></tt>, then you should probably preserve
your setting as <tt class="literal"><span class="pre">SESSION_COOKIE_PATH</span></tt>.  The default of <tt class="literal"><span class="pre">None</span></tt> means
that browsers will only send session cookies with requests for URIs
under the URI that originally resulted in the session cookie being sent.
See session-mgmt.txt and RFCs 2109 and 2965.</p>
<p>If you previously set <tt class="literal"><span class="pre">COOKIE_NAME</span></tt>, change it to
<tt class="literal"><span class="pre">SESSION_COOKIE_NAME</span></tt>.</p>
</div>
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python-quixote-doc 2.7~b2-1 / usr / share / doc / python-quixote-doc / upgrading.html
