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diff --git a/studio/static/doc/flask-docs/config.html b/studio/static/doc/flask-docs/config.html new file mode 100644 index 0000000..c569e8f --- /dev/null +++ b/studio/static/doc/flask-docs/config.html @@ -0,0 +1,505 @@ + +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> + + +<html xmlns="http://www.w3.org/1999/xhtml"> + <head> + <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> + + <title>Configuration Handling — Flask 0.8 documentation</title> + + <link rel="stylesheet" href="_static/flasky.css" type="text/css" /> + <link rel="stylesheet" href="_static/pygments.css" type="text/css" /> + + <script type="text/javascript"> + var DOCUMENTATION_OPTIONS = { + URL_ROOT: '', + VERSION: '0.8', + COLLAPSE_INDEX: false, + FILE_SUFFIX: '.html', + HAS_SOURCE: true + }; + </script> + <script type="text/javascript" src="_static/jquery.js"></script> + <script type="text/javascript" src="_static/underscore.js"></script> + <script type="text/javascript" src="_static/doctools.js"></script> + <link rel="top" title="Flask 0.8 documentation" href="index.html" /> + <link rel="next" title="Signals" href="signals.html" /> + <link rel="prev" title="Handling Application Errors" href="errorhandling.html" /> + + + <link rel="apple-touch-icon" href="_static/touch-icon.png" /> + + <link media="only screen and (max-device-width: 480px)" href="_static/small_flask.css" type= "text/css" rel="stylesheet" /> + + </head> + <body> + <div class="related"> + <h3>Navigation</h3> + <ul> + <li class="right" style="margin-right: 10px"> + <a href="genindex.html" title="General Index" + accesskey="I">index</a></li> + <li class="right" > + <a href="signals.html" title="Signals" + accesskey="N">next</a> |</li> + <li class="right" > + <a href="errorhandling.html" title="Handling Application Errors" + accesskey="P">previous</a> |</li> + <li><a href="index.html">Flask 0.8 documentation</a> »</li> + </ul> + </div> + + <div class="document"> + <div class="documentwrapper"> + <div class="bodywrapper"> + <div class="body"> + + <div class="section" id="configuration-handling"> +<span id="config"></span><h1>Configuration Handling<a class="headerlink" href="#configuration-handling" title="Permalink to this headline">¶</a></h1> +<p class="versionadded"> +<span class="versionmodified">New in version 0.3.</span></p> +<p>Applications need some kind of configuration. There are different settings +you might want to change depending on the application environment like +toggling the debug mode, setting the secret key, and other such +environment-specific things.</p> +<p>The way Flask is designed usually requires the configuration to be +available when the application starts up. You can hardcode the +configuration in the code, which for many small applications is not +actually that bad, but there are better ways.</p> +<p>Independent of how you load your config, there is a config object +available which holds the loaded configuration values: +The <a class="reference internal" href="api.html#flask.Flask.config" title="flask.Flask.config"><tt class="xref py py-attr docutils literal"><span class="pre">config</span></tt></a> attribute of the <a class="reference internal" href="api.html#flask.Flask" title="flask.Flask"><tt class="xref py py-class docutils literal"><span class="pre">Flask</span></tt></a> +object. This is the place where Flask itself puts certain configuration +values and also where extensions can put their configuration values. But +this is also where you can have your own configuration.</p> +<div class="section" id="configuration-basics"> +<h2>Configuration Basics<a class="headerlink" href="#configuration-basics" title="Permalink to this headline">¶</a></h2> +<p>The <a class="reference internal" href="api.html#flask.Flask.config" title="flask.Flask.config"><tt class="xref py py-attr docutils literal"><span class="pre">config</span></tt></a> is actually a subclass of a dictionary and +can be modified just like any dictionary:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">app</span> <span class="o">=</span> <span class="n">Flask</span><span class="p">(</span><span class="n">__name__</span><span class="p">)</span> +<span class="n">app</span><span class="o">.</span><span class="n">config</span><span class="p">[</span><span class="s">'DEBUG'</span><span class="p">]</span> <span class="o">=</span> <span class="bp">True</span> +</pre></div> +</div> +<p>Certain configuration values are also forwarded to the +<a class="reference internal" href="api.html#flask.Flask" title="flask.Flask"><tt class="xref py py-attr docutils literal"><span class="pre">Flask</span></tt></a> object so you can read and write them from there:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">app</span><span class="o">.</span><span class="n">debug</span> <span class="o">=</span> <span class="bp">True</span> +</pre></div> +</div> +<p>To update multiple keys at once you can use the <a class="reference external" href="http://docs.python.org/dev/library/stdtypes.html#dict.update" title="(in Python v3.3)"><tt class="xref py py-meth docutils literal"><span class="pre">dict.update()</span></tt></a> +method:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">app</span><span class="o">.</span><span class="n">config</span><span class="o">.</span><span class="n">update</span><span class="p">(</span> + <span class="n">DEBUG</span><span class="o">=</span><span class="bp">True</span><span class="p">,</span> + <span class="n">SECRET_KEY</span><span class="o">=</span><span class="s">'...'</span> +<span class="p">)</span> +</pre></div> +</div> +</div> +<div class="section" id="builtin-configuration-values"> +<h2>Builtin Configuration Values<a class="headerlink" href="#builtin-configuration-values" title="Permalink to this headline">¶</a></h2> +<p>The following configuration values are used internally by Flask:</p> +<table border="1" class="docutils"> +<colgroup> +<col width="45%" /> +<col width="55%" /> +</colgroup> +<tbody valign="top"> +<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">DEBUG</span></tt></td> +<td>enable/disable debug mode</td> +</tr> +<tr class="row-even"><td><tt class="docutils literal"><span class="pre">TESTING</span></tt></td> +<td>enable/disable testing mode</td> +</tr> +<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">PROPAGATE_EXCEPTIONS</span></tt></td> +<td>explicitly enable or disable the +propagation of exceptions. If not set or +explicitly set to <cite>None</cite> this is +implicitly true if either <cite>TESTING</cite> or +<cite>DEBUG</cite> is true.</td> +</tr> +<tr class="row-even"><td><tt class="docutils literal"><span class="pre">PRESERVE_CONTEXT_ON_EXCEPTION</span></tt></td> +<td>By default if the application is in +debug mode the request context is not +popped on exceptions to enable debuggers +to introspect the data. This can be +disabled by this key. You can also use +this setting to force-enable it for non +debug execution which might be useful to +debug production applications (but also +very risky).</td> +</tr> +<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">SECRET_KEY</span></tt></td> +<td>the secret key</td> +</tr> +<tr class="row-even"><td><tt class="docutils literal"><span class="pre">SESSION_COOKIE_NAME</span></tt></td> +<td>the name of the session cookie</td> +</tr> +<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">SESSION_COOKIE_DOMAIN</span></tt></td> +<td>the domain for the session cookie. If +this is not set, the cookie will be +valid for all subdomains of +<tt class="docutils literal"><span class="pre">SERVER_NAME</span></tt>.</td> +</tr> +<tr class="row-even"><td><tt class="docutils literal"><span class="pre">SESSION_COOKIE_PATH</span></tt></td> +<td>the path for the session cookie. If +this is not set the cookie will be valid +for all of <tt class="docutils literal"><span class="pre">APPLICATION_ROOT</span></tt> or if +that is not set for <tt class="docutils literal"><span class="pre">'/'</span></tt>.</td> +</tr> +<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">SESSION_COOKIE_HTTPONLY</span></tt></td> +<td>controls if the cookie should be set +with the httponly flag. Defaults to +<cite>True</cite>.</td> +</tr> +<tr class="row-even"><td><tt class="docutils literal"><span class="pre">SESSION_COOKIE_SECURE</span></tt></td> +<td>controls if the cookie should be set +with the secure flag. Defaults to +<cite>False</cite>.</td> +</tr> +<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">PERMANENT_SESSION_LIFETIME</span></tt></td> +<td>the lifetime of a permanent session as +<a class="reference external" href="http://docs.python.org/dev/library/datetime.html#datetime.timedelta" title="(in Python v3.3)"><tt class="xref py py-class docutils literal"><span class="pre">datetime.timedelta</span></tt></a> object. +Starting with Flask 0.8 this can also be +an integer representing seconds.</td> +</tr> +<tr class="row-even"><td><tt class="docutils literal"><span class="pre">USE_X_SENDFILE</span></tt></td> +<td>enable/disable x-sendfile</td> +</tr> +<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">LOGGER_NAME</span></tt></td> +<td>the name of the logger</td> +</tr> +<tr class="row-even"><td><tt class="docutils literal"><span class="pre">SERVER_NAME</span></tt></td> +<td>the name and port number of the server. +Required for subdomain support (e.g.: +<tt class="docutils literal"><span class="pre">'myapp.dev:5000'</span></tt>) Note that +localhost does not support subdomains so +setting this to “localhost” does not +help.</td> +</tr> +<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">APPLICATION_ROOT</span></tt></td> +<td>If the application does not occupy +a whole domain or subdomain this can +be set to the path where the application +is configured to live. This is for +session cookie as path value. If +domains are used, this should be +<tt class="docutils literal"><span class="pre">None</span></tt>.</td> +</tr> +<tr class="row-even"><td><tt class="docutils literal"><span class="pre">MAX_CONTENT_LENGTH</span></tt></td> +<td>If set to a value in bytes, Flask will +reject incoming requests with a +content length greater than this by +returning a 413 status code.</td> +</tr> +<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">TRAP_HTTP_EXCEPTIONS</span></tt></td> +<td>If this is set to <tt class="docutils literal"><span class="pre">True</span></tt> Flask will +not execute the error handlers of HTTP +exceptions but instead treat the +exception like any other and bubble it +through the exception stack. This is +helpful for hairy debugging situations +where you have to find out where an HTTP +exception is coming from.</td> +</tr> +<tr class="row-even"><td><tt class="docutils literal"><span class="pre">TRAP_BAD_REQUEST_ERRORS</span></tt></td> +<td>Werkzeug’s internal data structures that +deal with request specific data will +raise special key errors that are also +bad request exceptions. Likewise many +operations can implicitly fail with a +BadRequest exception for consistency. +Since it’s nice for debugging to know +why exactly it failed this flag can be +used to debug those situations. If this +config is set to <tt class="docutils literal"><span class="pre">True</span></tt> you will get +a regular traceback instead.</td> +</tr> +</tbody> +</table> +<div class="admonition-more-on-server-name admonition "> +<p class="first admonition-title">More on <tt class="docutils literal"><span class="pre">SERVER_NAME</span></tt></p> +<p>The <tt class="docutils literal"><span class="pre">SERVER_NAME</span></tt> key is used for the subdomain support. Because +Flask cannot guess the subdomain part without the knowledge of the +actual server name, this is required if you want to work with +subdomains. This is also used for the session cookie.</p> +<p class="last">Please keep in mind that not only Flask has the problem of not knowing +what subdomains are, your web browser does as well. Most modern web +browsers will not allow cross-subdomain cookies to be set on a +server name without dots in it. So if your server name is +<tt class="docutils literal"><span class="pre">'localhost'</span></tt> you will not be able to set a cookie for +<tt class="docutils literal"><span class="pre">'localhost'</span></tt> and every subdomain of it. Please chose a different +server name in that case, like <tt class="docutils literal"><span class="pre">'myapplication.local'</span></tt> and add +this name + the subdomains you want to use into your host config +or setup a local <a class="reference external" href="https://www.isc.org/software/bind">bind</a>.</p> +</div> +<p class="versionadded"> +<span class="versionmodified">New in version 0.4: </span><tt class="docutils literal"><span class="pre">LOGGER_NAME</span></tt></p> +<p class="versionadded"> +<span class="versionmodified">New in version 0.5: </span><tt class="docutils literal"><span class="pre">SERVER_NAME</span></tt></p> +<p class="versionadded"> +<span class="versionmodified">New in version 0.6: </span><tt class="docutils literal"><span class="pre">MAX_CONTENT_LENGTH</span></tt></p> +<p class="versionadded"> +<span class="versionmodified">New in version 0.7: </span><tt class="docutils literal"><span class="pre">PROPAGATE_EXCEPTIONS</span></tt>, <tt class="docutils literal"><span class="pre">PRESERVE_CONTEXT_ON_EXCEPTION</span></tt></p> +<p class="versionadded"> +<span class="versionmodified">New in version 0.8: </span><tt class="docutils literal"><span class="pre">TRAP_BAD_REQUEST_ERRORS</span></tt>, <tt class="docutils literal"><span class="pre">TRAP_HTTP_EXCEPTIONS</span></tt>, +<tt class="docutils literal"><span class="pre">APPLICATION_ROOT</span></tt>, <tt class="docutils literal"><span class="pre">SESSION_COOKIE_DOMAIN</span></tt>, +<tt class="docutils literal"><span class="pre">SESSION_COOKIE_PATH</span></tt>, <tt class="docutils literal"><span class="pre">SESSION_COOKIE_HTTPONLY</span></tt>, +<tt class="docutils literal"><span class="pre">SESSION_COOKIE_SECURE</span></tt></p> +</div> +<div class="section" id="configuring-from-files"> +<h2>Configuring from Files<a class="headerlink" href="#configuring-from-files" title="Permalink to this headline">¶</a></h2> +<p>Configuration becomes more useful if you can store it in a separate file, +ideally located outside the actual application package. This makes +packaging and distributing your application possible via various package +handling tools (<a class="reference internal" href="patterns/distribute.html#distribute-deployment"><em>Deploying with Distribute</em></a>) and finally modifying the +configuration file afterwards.</p> +<p>So a common pattern is this:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">app</span> <span class="o">=</span> <span class="n">Flask</span><span class="p">(</span><span class="n">__name__</span><span class="p">)</span> +<span class="n">app</span><span class="o">.</span><span class="n">config</span><span class="o">.</span><span class="n">from_object</span><span class="p">(</span><span class="s">'yourapplication.default_settings'</span><span class="p">)</span> +<span class="n">app</span><span class="o">.</span><span class="n">config</span><span class="o">.</span><span class="n">from_envvar</span><span class="p">(</span><span class="s">'YOURAPPLICATION_SETTINGS'</span><span class="p">)</span> +</pre></div> +</div> +<p>This first loads the configuration from the +<cite>yourapplication.default_settings</cite> module and then overrides the values +with the contents of the file the <span class="target" id="index-0"></span><tt class="xref std std-envvar docutils literal"><span class="pre">YOURAPPLICATION_SETTINGS</span></tt> +environment variable points to. This environment variable can be set on +Linux or OS X with the export command in the shell before starting the +server:</p> +<div class="highlight-python"><pre>$ export YOURAPPLICATION_SETTINGS=/path/to/settings.cfg +$ python run-app.py + * Running on http://127.0.0.1:5000/ + * Restarting with reloader...</pre> +</div> +<p>On Windows systems use the <cite>set</cite> builtin instead:</p> +<div class="highlight-python"><pre>>set YOURAPPLICATION_SETTINGS=\path\to\settings.cfg</pre> +</div> +<p>The configuration files themselves are actual Python files. Only values +in uppercase are actually stored in the config object later on. So make +sure to use uppercase letters for your config keys.</p> +<p>Here is an example of a configuration file:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="c"># Example configuration</span> +<span class="n">DEBUG</span> <span class="o">=</span> <span class="bp">False</span> +<span class="n">SECRET_KEY</span> <span class="o">=</span> <span class="s">'?</span><span class="se">\xbf</span><span class="s">,</span><span class="se">\xb4\x8d\xa3</span><span class="s">"<</span><span class="se">\x9c\xb0</span><span class="s">@</span><span class="se">\x0f</span><span class="s">5</span><span class="se">\xab</span><span class="s">,w</span><span class="se">\xee\x8d</span><span class="s">$0</span><span class="se">\x13\x8b</span><span class="s">83'</span> +</pre></div> +</div> +<p>Make sure to load the configuration very early on, so that extensions have +the ability to access the configuration when starting up. There are other +methods on the config object as well to load from individual files. For a +complete reference, read the <a class="reference internal" href="api.html#flask.Config" title="flask.Config"><tt class="xref py py-class docutils literal"><span class="pre">Config</span></tt></a> object’s +documentation.</p> +</div> +<div class="section" id="configuration-best-practices"> +<h2>Configuration Best Practices<a class="headerlink" href="#configuration-best-practices" title="Permalink to this headline">¶</a></h2> +<p>The downside with the approach mentioned earlier is that it makes testing +a little harder. There is no single 100% solution for this problem in +general, but there are a couple of things you can keep in mind to improve +that experience:</p> +<ol class="arabic simple"> +<li>create your application in a function and register blueprints on it. +That way you can create multiple instances of your application with +different configurations attached which makes unittesting a lot +easier. You can use this to pass in configuration as needed.</li> +<li>Do not write code that needs the configuration at import time. If you +limit yourself to request-only accesses to the configuration you can +reconfigure the object later on as needed.</li> +</ol> +</div> +<div class="section" id="development-production"> +<h2>Development / Production<a class="headerlink" href="#development-production" title="Permalink to this headline">¶</a></h2> +<p>Most applications need more than one configuration. There should be at +least separate configurations for the production server and the one used +during development. The easiest way to handle this is to use a default +configuration that is always loaded and part of the version control, and a +separate configuration that overrides the values as necessary as mentioned +in the example above:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">app</span> <span class="o">=</span> <span class="n">Flask</span><span class="p">(</span><span class="n">__name__</span><span class="p">)</span> +<span class="n">app</span><span class="o">.</span><span class="n">config</span><span class="o">.</span><span class="n">from_object</span><span class="p">(</span><span class="s">'yourapplication.default_settings'</span><span class="p">)</span> +<span class="n">app</span><span class="o">.</span><span class="n">config</span><span class="o">.</span><span class="n">from_envvar</span><span class="p">(</span><span class="s">'YOURAPPLICATION_SETTINGS'</span><span class="p">)</span> +</pre></div> +</div> +<p>Then you just have to add a separate <cite>config.py</cite> file and export +<tt class="docutils literal"><span class="pre">YOURAPPLICATION_SETTINGS=/path/to/config.py</span></tt> and you are done. However +there are alternative ways as well. For example you could use imports or +subclassing.</p> +<p>What is very popular in the Django world is to make the import explicit in +the config file by adding an <tt class="docutils literal"><span class="pre">from</span> <span class="pre">yourapplication.default_settings</span> +<span class="pre">import</span> <span class="pre">*</span></tt> to the top of the file and then overriding the changes by hand. +You could also inspect an environment variable like +<tt class="docutils literal"><span class="pre">YOURAPPLICATION_MODE</span></tt> and set that to <cite>production</cite>, <cite>development</cite> etc +and import different hardcoded files based on that.</p> +<p>An interesting pattern is also to use classes and inheritance for +configuration:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="k">class</span> <span class="nc">Config</span><span class="p">(</span><span class="nb">object</span><span class="p">):</span> + <span class="n">DEBUG</span> <span class="o">=</span> <span class="bp">False</span> + <span class="n">TESTING</span> <span class="o">=</span> <span class="bp">False</span> + <span class="n">DATABASE_URI</span> <span class="o">=</span> <span class="s">'sqlite://:memory:'</span> + +<span class="k">class</span> <span class="nc">ProductionConfig</span><span class="p">(</span><span class="n">Config</span><span class="p">):</span> + <span class="n">DATABASE_URI</span> <span class="o">=</span> <span class="s">'mysql://user@localhost/foo'</span> + +<span class="k">class</span> <span class="nc">DevelopmentConfig</span><span class="p">(</span><span class="n">Config</span><span class="p">):</span> + <span class="n">DEBUG</span> <span class="o">=</span> <span class="bp">True</span> + +<span class="k">class</span> <span class="nc">TestingConfig</span><span class="p">(</span><span class="n">Config</span><span class="p">):</span> + <span class="n">TESTING</span> <span class="o">=</span> <span class="bp">True</span> +</pre></div> +</div> +<p>To enable such a config you just have to call into +<a class="reference internal" href="api.html#flask.Config.from_object" title="flask.Config.from_object"><tt class="xref py py-meth docutils literal"><span class="pre">from_object()</span></tt></a>:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">app</span><span class="o">.</span><span class="n">config</span><span class="o">.</span><span class="n">from_object</span><span class="p">(</span><span class="s">'configmodule.ProductionConfig'</span><span class="p">)</span> +</pre></div> +</div> +<p>There are many different ways and it’s up to you how you want to manage +your configuration files. However here a list of good recommendations:</p> +<ul class="simple"> +<li>keep a default configuration in version control. Either populate the +config with this default configuration or import it in your own +configuration files before overriding values.</li> +<li>use an environment variable to switch between the configurations. +This can be done from outside the Python interpreter and makes +development and deployment much easier because you can quickly and +easily switch between different configs without having to touch the +code at all. If you are working often on different projects you can +even create your own script for sourcing that activates a virtualenv +and exports the development configuration for you.</li> +<li>Use a tool like <a class="reference external" href="http://fabfile.org/">fabric</a> in production to push code and +configurations separately to the production server(s). For some +details about how to do that, head over to the +<a class="reference internal" href="patterns/fabric.html#fabric-deployment"><em>Deploying with Fabric</em></a> pattern.</li> +</ul> +</div> +<div class="section" id="instance-folders"> +<span id="id1"></span><h2>Instance Folders<a class="headerlink" href="#instance-folders" title="Permalink to this headline">¶</a></h2> +<p class="versionadded"> +<span class="versionmodified">New in version 0.8.</span></p> +<p>Flask 0.8 introduces instance folders. Flask for a long time made it +possible to refer to paths relative to the application’s folder directly +(via <tt class="xref py py-attr docutils literal"><span class="pre">Flask.root_path</span></tt>). This was also how many developers loaded +configurations stored next to the application. Unfortunately however this +only works well if applications are not packages in which case the root +path refers to the contents of the package.</p> +<p>With Flask 0.8 a new attribute was introduced: +<tt class="xref py py-attr docutils literal"><span class="pre">Flask.instance_path</span></tt>. It refers to a new concept called the +“instance folder”. The instance folder is designed to not be under +version control and be deployment specific. It’s the perfect place to +drop things that either change at runtime or configuration files.</p> +<p>You can either explicitly provide the path of the instance folder when +creating the Flask application or you can let Flask autodetect the +instance folder. For explicit configuration use the <cite>instance_path</cite> +parameter:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">app</span> <span class="o">=</span> <span class="n">Flask</span><span class="p">(</span><span class="n">__name__</span><span class="p">,</span> <span class="n">instance_path</span><span class="o">=</span><span class="s">'/path/to/instance/folder'</span><span class="p">)</span> +</pre></div> +</div> +<p>Please keep in mind that this path <em>must</em> be absolute when provided.</p> +<p>If the <cite>instance_path</cite> parameter is not provided the following default +locations are used:</p> +<ul> +<li><p class="first">Uninstalled module:</p> +<div class="highlight-python"><pre>/myapp.py +/instance</pre> +</div> +</li> +<li><p class="first">Uninstalled package:</p> +<div class="highlight-python"><pre>/myapp + /__init__.py +/instance</pre> +</div> +</li> +<li><p class="first">Installed module or package:</p> +<div class="highlight-python"><pre>$PREFIX/lib/python2.X/site-packages/myapp +$PREFIX/var/myapp-instance</pre> +</div> +<p><tt class="docutils literal"><span class="pre">$PREFIX</span></tt> is the prefix of your Python installation. This can be +<tt class="docutils literal"><span class="pre">/usr</span></tt> or the path to your virtualenv. You can print the value of +<tt class="docutils literal"><span class="pre">sys.prefix</span></tt> to see what the prefix is set to.</p> +</li> +</ul> +<p>Since the config object provided loading of configuration files from +relative filenames we made it possible to change the loading via filenames +to be relative to the instance path if wanted. The behavior of relative +paths in config files can be flipped between “relative to the application +root” (the default) to “relative to instance folder” via the +<cite>instance_relative_config</cite> switch to the application constructor:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">app</span> <span class="o">=</span> <span class="n">Flask</span><span class="p">(</span><span class="n">__name__</span><span class="p">,</span> <span class="n">instance_relative_config</span><span class="o">=</span><span class="bp">True</span><span class="p">)</span> +</pre></div> +</div> +<p>Here is a full example of how to configure Flask to preload the config +from a module and then override the config from a file in the config +folder if it exists:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">app</span> <span class="o">=</span> <span class="n">Flask</span><span class="p">(</span><span class="n">__name__</span><span class="p">,</span> <span class="n">instance_relative_config</span><span class="o">=</span><span class="bp">True</span><span class="p">)</span> +<span class="n">app</span><span class="o">.</span><span class="n">config</span><span class="o">.</span><span class="n">from_object</span><span class="p">(</span><span class="s">'yourapplication.default_settings'</span><span class="p">)</span> +<span class="n">app</span><span class="o">.</span><span class="n">config</span><span class="o">.</span><span class="n">from_pyfile</span><span class="p">(</span><span class="s">'application.cfg'</span><span class="p">,</span> <span class="n">silent</span><span class="o">=</span><span class="bp">True</span><span class="p">)</span> +</pre></div> +</div> +<p>The path to the instance folder can be found via the +<tt class="xref py py-attr docutils literal"><span class="pre">Flask.instance_path</span></tt>. Flask also provides a shortcut to open a +file from the instance folder with <tt class="xref py py-meth docutils literal"><span class="pre">Flask.open_instance_resource()</span></tt>.</p> +<p>Example usage for both:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">filename</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">app</span><span class="o">.</span><span class="n">instance_root</span><span class="p">,</span> <span class="s">'application.cfg'</span><span class="p">)</span> +<span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="n">filename</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span> + <span class="n">config</span> <span class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">()</span> + +<span class="c"># or via open_instance_resource:</span> +<span class="k">with</span> <span class="n">app</span><span class="o">.</span><span class="n">open_instance_resource</span><span class="p">(</span><span class="s">'application.cfg'</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span> + <span class="n">config</span> <span class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">()</span> +</pre></div> +</div> +</div> +</div> + + + </div> + </div> + </div> + <div class="sphinxsidebar"> + <div class="sphinxsidebarwrapper"><p class="logo"><a href="index.html"> + <img class="logo" src="_static/flask.png" alt="Logo"/> +</a></p> + <h3><a href="index.html">Table Of Contents</a></h3> + <ul> +<li><a class="reference internal" href="#">Configuration Handling</a><ul> +<li><a class="reference internal" href="#configuration-basics">Configuration Basics</a></li> +<li><a class="reference internal" href="#builtin-configuration-values">Builtin Configuration Values</a></li> +<li><a class="reference internal" href="#configuring-from-files">Configuring from Files</a></li> +<li><a class="reference internal" href="#configuration-best-practices">Configuration Best Practices</a></li> +<li><a class="reference internal" href="#development-production">Development / Production</a></li> +<li><a class="reference internal" href="#instance-folders">Instance Folders</a></li> +</ul> +</li> +</ul> +<h3>Related Topics</h3> +<ul> + <li><a href="index.html">Documentation overview</a><ul> + <li>Previous: <a href="errorhandling.html" title="previous chapter">Handling Application Errors</a></li> + <li>Next: <a href="signals.html" title="next chapter">Signals</a></li> + </ul></li> +</ul> + <h3>This Page</h3> + <ul class="this-page-menu"> + <li><a href="_sources/config.txt" + rel="nofollow">Show Source</a></li> + </ul> +<div id="searchbox" style="display: none"> + <h3>Quick search</h3> + <form class="search" action="search.html" method="get"> + <input type="text" name="q" /> + <input type="submit" value="Go" /> + <input type="hidden" name="check_keywords" value="yes" /> + <input type="hidden" name="area" value="default" /> + </form> + <p class="searchtip" style="font-size: 90%"> + Enter search terms or a module, class or function name. + </p> +</div> +<script type="text/javascript">$('#searchbox').show(0);</script> + </div> + </div> + <div class="clearer"></div> + </div> + <div class="footer"> + © Copyright 2010, Armin Ronacher. + Created using <a href="http://sphinx.pocoo.org/">Sphinx</a>. + </div> + </body> +</html>
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