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diff --git a/app/static/doc/flask-docs/blueprints.html b/app/static/doc/flask-docs/blueprints.html new file mode 100644 index 0000000..271aa3d --- /dev/null +++ b/app/static/doc/flask-docs/blueprints.html @@ -0,0 +1,306 @@ + +<!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>Modular Applications with Blueprints — 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="Flask Extensions" href="extensions.html" /> + <link rel="prev" title="The Request Context" href="reqcontext.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="extensions.html" title="Flask Extensions" + accesskey="N">next</a> |</li> + <li class="right" > + <a href="reqcontext.html" title="The Request Context" + 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="modular-applications-with-blueprints"> +<span id="blueprints"></span><h1>Modular Applications with Blueprints<a class="headerlink" href="#modular-applications-with-blueprints" title="Permalink to this headline">¶</a></h1> +<p class="versionadded"> +<span class="versionmodified">New in version 0.7.</span></p> +<p>Flask uses a concept of <em>blueprints</em> for making application components and +supporting common patterns within an application or across applications. +Blueprints can greatly simplify how large applications work and provide a +central means for Flask extensions to register operations on applications. +A <tt class="xref py py-class docutils literal"><span class="pre">Blueprint</span></tt> object works similarly to a <tt class="xref py py-class docutils literal"><span class="pre">Flask</span></tt> +application object, but it is not actually an application. Rather it is a +<em>blueprint</em> of how to construct or extend an application.</p> +<div class="section" id="why-blueprints"> +<h2>Why Blueprints?<a class="headerlink" href="#why-blueprints" title="Permalink to this headline">¶</a></h2> +<p>Blueprints in Flask are intended for these cases:</p> +<ul class="simple"> +<li>Factor an application into a set of blueprints. This is ideal for +larger applications; a project could instantiate an application object, +initialize several extensions, and register a collection of blueprints.</li> +<li>Register a blueprint on an application at a URL prefix and/or subdomain. +Parameters in the URL prefix/subdomain become common view arguments +(with defaults) across all view functions in the blueprint.</li> +<li>Register a blueprint multiple times on an application with different URL +rules.</li> +<li>Provide template filters, static files, templates, and other utilities +through blueprints. A blueprint does not have to implement applications +or view functions.</li> +<li>Register a blueprint on an application for any of these cases when +initializing a Flask extension.</li> +</ul> +<p>A blueprint in Flask is not a pluggable app because it is not actually an +application – it’s a set of operations which can be registered on an +application, even multiple times. Why not have multiple application +objects? You can do that (see <a class="reference internal" href="patterns/appdispatch.html#app-dispatch"><em>Application Dispatching</em></a>), but your applications +will have separate configs and will be managed at the WSGI layer.</p> +<p>Blueprints instead provide separation at the Flask level, share +application config, and can change an application object as necessary with +being registered. The downside is that you cannot unregister a blueprint +once an application was created without having to destroy the whole +application object.</p> +</div> +<div class="section" id="the-concept-of-blueprints"> +<h2>The Concept of Blueprints<a class="headerlink" href="#the-concept-of-blueprints" title="Permalink to this headline">¶</a></h2> +<p>The basic concept of blueprints is that they record operations to execute +when registered on an application. Flask associates view functions with +blueprints when dispatching requests and generating URLs from one endpoint +to another.</p> +</div> +<div class="section" id="my-first-blueprint"> +<h2>My First Blueprint<a class="headerlink" href="#my-first-blueprint" title="Permalink to this headline">¶</a></h2> +<p>This is what a very basic blueprint looks like. In this case we want to +implement a blueprint that does simple rendering of static templates:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="kn">from</span> <span class="nn">flask</span> <span class="kn">import</span> <span class="n">Blueprint</span><span class="p">,</span> <span class="n">render_template</span><span class="p">,</span> <span class="n">abort</span> +<span class="kn">from</span> <span class="nn">jinja2</span> <span class="kn">import</span> <span class="n">TemplateNotFound</span> + +<span class="n">simple_page</span> <span class="o">=</span> <span class="n">Blueprint</span><span class="p">(</span><span class="s">'simple_page'</span><span class="p">,</span> <span class="n">__name__</span><span class="p">)</span> + +<span class="nd">@simple_page.route</span><span class="p">(</span><span class="s">'/'</span><span class="p">,</span> <span class="n">defaults</span><span class="o">=</span><span class="p">{</span><span class="s">'page'</span><span class="p">:</span> <span class="s">'index'</span><span class="p">})</span> +<span class="nd">@simple_page.route</span><span class="p">(</span><span class="s">'/<page>'</span><span class="p">)</span> +<span class="k">def</span> <span class="nf">show</span><span class="p">(</span><span class="n">page</span><span class="p">):</span> + <span class="k">try</span><span class="p">:</span> + <span class="k">return</span> <span class="n">render_template</span><span class="p">(</span><span class="s">'pages/</span><span class="si">%s</span><span class="s">.html'</span> <span class="o">%</span> <span class="n">page</span><span class="p">)</span> + <span class="k">except</span> <span class="n">TemplateNotFound</span><span class="p">:</span> + <span class="n">abort</span><span class="p">(</span><span class="mi">404</span><span class="p">)</span> +</pre></div> +</div> +<p>When you bind a function with the help of the <tt class="docutils literal"><span class="pre">@simple_page.route</span></tt> +decorator the blueprint will record the intention of registering the +function <cite>show</cite> on the application when it’s later registered. +Additionally it will prefix the endpoint of the function with the +name of the blueprint which was given to the <tt class="xref py py-class docutils literal"><span class="pre">Blueprint</span></tt> +constructor (in this case also <tt class="docutils literal"><span class="pre">simple_page</span></tt>).</p> +</div> +<div class="section" id="registering-blueprints"> +<h2>Registering Blueprints<a class="headerlink" href="#registering-blueprints" title="Permalink to this headline">¶</a></h2> +<p>So how do you register that blueprint? Like this:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="kn">from</span> <span class="nn">flask</span> <span class="kn">import</span> <span class="n">Flask</span> +<span class="kn">from</span> <span class="nn">yourapplication.simple_page</span> <span class="kn">import</span> <span class="n">simple_page</span> + +<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">register_blueprint</span><span class="p">(</span><span class="n">simple_page</span><span class="p">)</span> +</pre></div> +</div> +<p>If you check the rules registered on the application, you will find +these:</p> +<div class="highlight-python"><pre>[<Rule '/static/<filename>' (HEAD, OPTIONS, GET) -> static>, + <Rule '/<page>' (HEAD, OPTIONS, GET) -> simple_page.show>, + <Rule '/' (HEAD, OPTIONS, GET) -> simple_page.show>]</pre> +</div> +<p>The first one is obviously from the application ifself for the static +files. The other two are for the <cite>show</cite> function of the <tt class="docutils literal"><span class="pre">simple_page</span></tt> +blueprint. As you can see, they are also prefixed with the name of the +blueprint and separated by a dot (<tt class="docutils literal"><span class="pre">.</span></tt>).</p> +<p>Blueprints however can also be mounted at different locations:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">app</span><span class="o">.</span><span class="n">register_blueprint</span><span class="p">(</span><span class="n">simple_page</span><span class="p">,</span> <span class="n">url_prefix</span><span class="o">=</span><span class="s">'/pages'</span><span class="p">)</span> +</pre></div> +</div> +<p>And sure enough, these are the generated rules:</p> +<div class="highlight-python"><pre>[<Rule '/static/<filename>' (HEAD, OPTIONS, GET) -> static>, + <Rule '/pages/<page>' (HEAD, OPTIONS, GET) -> simple_page.show>, + <Rule '/pages/' (HEAD, OPTIONS, GET) -> simple_page.show>]</pre> +</div> +<p>On top of that you can register blueprints multiple times though not every +blueprint might respond properly to that. In fact it depends on how the +blueprint is implemented if it can be mounted more than once.</p> +</div> +<div class="section" id="blueprint-resources"> +<h2>Blueprint Resources<a class="headerlink" href="#blueprint-resources" title="Permalink to this headline">¶</a></h2> +<p>Blueprints can provide resources as well. Sometimes you might want to +introduce a blueprint only for the resources it provides.</p> +<div class="section" id="blueprint-resource-folder"> +<h3>Blueprint Resource Folder<a class="headerlink" href="#blueprint-resource-folder" title="Permalink to this headline">¶</a></h3> +<p>Like for regular applications, blueprints are considered to be contained +in a folder. While multiple blueprints can originate from the same folder, +it does not have to be the case and it’s usually not recommended.</p> +<p>The folder is inferred from the second argument to <tt class="xref py py-class docutils literal"><span class="pre">Blueprint</span></tt> which +is usually <cite>__name__</cite>. This argument specifies what logical Python +module or package corresponds to the blueprint. If it points to an actual +Python package that package (which is a folder on the filesystem) is the +resource folder. If it’s a module, the package the module is contained in +will be the resource folder. You can access the +<tt class="xref py py-attr docutils literal"><span class="pre">Blueprint.root_path</span></tt> property to see what the resource folder is:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="n">simple_page</span><span class="o">.</span><span class="n">root_path</span> +<span class="go">'/Users/username/TestProject/yourapplication'</span> +</pre></div> +</div> +<p>To quickly open sources from this folder you can use the +<tt class="xref py py-meth docutils literal"><span class="pre">open_resource()</span></tt> function:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="k">with</span> <span class="n">simple_page</span><span class="o">.</span><span class="n">open_resource</span><span class="p">(</span><span class="s">'static/style.css'</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span> + <span class="n">code</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 class="section" id="static-files"> +<h3>Static Files<a class="headerlink" href="#static-files" title="Permalink to this headline">¶</a></h3> +<p>A blueprint can expose a folder with static files by providing a path to a +folder on the filesystem via the <cite>static_folder</cite> keyword argument. It can +either be an absolute path or one relative to the folder of the +blueprint:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">admin</span> <span class="o">=</span> <span class="n">Blueprint</span><span class="p">(</span><span class="s">'admin'</span><span class="p">,</span> <span class="n">__name__</span><span class="p">,</span> <span class="n">static_folder</span><span class="o">=</span><span class="s">'static'</span><span class="p">)</span> +</pre></div> +</div> +<p>By default the rightmost part of the path is where it is exposed on the +web. Because the folder is called <tt class="docutils literal"><span class="pre">static</span></tt> here it will be available at +the location of the blueprint + <tt class="docutils literal"><span class="pre">/static</span></tt>. Say the blueprint is +registered for <tt class="docutils literal"><span class="pre">/admin</span></tt> the static folder will be at <tt class="docutils literal"><span class="pre">/admin/static</span></tt>.</p> +<p>The endpoint is named <cite>blueprint_name.static</cite> so you can generate URLs to +it like you would do to the static folder of the application:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">url_for</span><span class="p">(</span><span class="s">'admin.static'</span><span class="p">,</span> <span class="n">filename</span><span class="o">=</span><span class="s">'style.css'</span><span class="p">)</span> +</pre></div> +</div> +</div> +<div class="section" id="templates"> +<h3>Templates<a class="headerlink" href="#templates" title="Permalink to this headline">¶</a></h3> +<p>If you want the blueprint to expose templates you can do that by providing +the <cite>template_folder</cite> parameter to the <tt class="xref py py-class docutils literal"><span class="pre">Blueprint</span></tt> constructor:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">admin</span> <span class="o">=</span> <span class="n">Blueprint</span><span class="p">(</span><span class="s">'admin'</span><span class="p">,</span> <span class="n">__name__</span><span class="p">,</span> <span class="n">template_folder</span><span class="o">=</span><span class="s">'templates'</span><span class="p">)</span> +</pre></div> +</div> +<p>As for static files, the path can be absolute or relative to the blueprint +resource folder. The template folder is added to the searchpath of +templates but with a lower priority than the actual application’s template +folder. That way you can easily override templates that a blueprint +provides in the actual application.</p> +<p>So if you have a blueprint in the folder <tt class="docutils literal"><span class="pre">yourapplication/admin</span></tt> and you +want to render the template <tt class="docutils literal"><span class="pre">'admin/index.html'</span></tt> and you have provided +<tt class="docutils literal"><span class="pre">templates</span></tt> as a <cite>template_folder</cite> you will have to create a file like +this: <tt class="docutils literal"><span class="pre">yourapplication/admin/templates/admin/index.html</span></tt>.</p> +</div> +</div> +<div class="section" id="building-urls"> +<h2>Building URLs<a class="headerlink" href="#building-urls" title="Permalink to this headline">¶</a></h2> +<p>If you want to link from one page to another you can use the +<tt class="xref py py-func docutils literal"><span class="pre">url_for()</span></tt> function just like you normally would do just that you +prefix the URL endpoint with the name of the blueprint and a dot (<tt class="docutils literal"><span class="pre">.</span></tt>):</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">url_for</span><span class="p">(</span><span class="s">'admin.index'</span><span class="p">)</span> +</pre></div> +</div> +<p>Additionally if you are in a view function of a blueprint or a rendered +template and you want to link to another endpoint of the same blueprint, +you can use relative redirects by prefixing the endpoint with a dot only:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">url_for</span><span class="p">(</span><span class="s">'.index'</span><span class="p">)</span> +</pre></div> +</div> +<p>This will link to <tt class="docutils literal"><span class="pre">admin.index</span></tt> for instance in case the current request +was dispatched to any other admin blueprint endpoint.</p> +</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="#">Modular Applications with Blueprints</a><ul> +<li><a class="reference internal" href="#why-blueprints">Why Blueprints?</a></li> +<li><a class="reference internal" href="#the-concept-of-blueprints">The Concept of Blueprints</a></li> +<li><a class="reference internal" href="#my-first-blueprint">My First Blueprint</a></li> +<li><a class="reference internal" href="#registering-blueprints">Registering Blueprints</a></li> +<li><a class="reference internal" href="#blueprint-resources">Blueprint Resources</a><ul> +<li><a class="reference internal" href="#blueprint-resource-folder">Blueprint Resource Folder</a></li> +<li><a class="reference internal" href="#static-files">Static Files</a></li> +<li><a class="reference internal" href="#templates">Templates</a></li> +</ul> +</li> +<li><a class="reference internal" href="#building-urls">Building URLs</a></li> +</ul> +</li> +</ul> +<h3>Related Topics</h3> +<ul> + <li><a href="index.html">Documentation overview</a><ul> + <li>Previous: <a href="reqcontext.html" title="previous chapter">The Request Context</a></li> + <li>Next: <a href="extensions.html" title="next chapter">Flask Extensions</a></li> + </ul></li> +</ul> + <h3>This Page</h3> + <ul class="this-page-menu"> + <li><a href="_sources/blueprints.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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