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<div class="section" id="module-horizon.workflows">
<span id="horizon-workflows"></span><h1>Horizon Workflows<a class="headerlink" href="#module-horizon.workflows" title="Permalink to this headline">¶</a></h1>
<p>One of the most challenging aspects of building a compelling user experience
is crafting complex multi-part workflows. Horizon’s <tt class="docutils literal"><span class="pre">workflows</span></tt> module
aims to bring that capability within everyday reach.</p>
<div class="section" id="workflows">
<h2>Workflows<a class="headerlink" href="#workflows" title="Permalink to this headline">¶</a></h2>
<dl class="class">
<dt id="horizon.workflows.Workflow">
<em class="property">class </em><tt class="descclassname">horizon.workflows.</tt><tt class="descname">Workflow</tt><big>(</big><em>request=None</em>, <em>context_seed=None</em>, <em>entry_point=None</em>, <em>*args</em>, <em>**kwargs</em><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow" title="Permalink to this definition">¶</a></dt>
<dd><p>A Workflow is a collection of Steps. It’s interface is very
straightforward, but it is responsible for handling some very
important tasks such as:</p>
<ul class="simple">
<li>Handling the injection, removal, and ordering of arbitrary steps.</li>
<li>Determining if the workflow can be completed by a given user at runtime
based on all available information.</li>
<li>Dispatching connections between steps to ensure that when context data
changes all the applicable callback functions are executed.</li>
<li>Verifying/validating the overall data integrity and subsequently
triggering the final method to complete the workflow.</li>
</ul>
<p>The <tt class="docutils literal"><span class="pre">Workflow</span></tt> class has the following attributes:</p>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.name">
<tt class="descname">name</tt><a class="headerlink" href="#horizon.workflows.Workflow.name" title="Permalink to this definition">¶</a></dt>
<dd><p>The verbose name for this workflow which will be displayed to the user.
Defaults to the class name.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.slug">
<tt class="descname">slug</tt><a class="headerlink" href="#horizon.workflows.Workflow.slug" title="Permalink to this definition">¶</a></dt>
<dd><p>The unique slug for this workflow. Required.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.steps">
<tt class="descname">steps</tt><a class="headerlink" href="#horizon.workflows.Workflow.steps" title="Permalink to this definition">¶</a></dt>
<dd><p>Read-only access to the final ordered set of step instances for
this workflow.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.default_steps">
<tt class="descname">default_steps</tt><a class="headerlink" href="#horizon.workflows.Workflow.default_steps" title="Permalink to this definition">¶</a></dt>
<dd><p>A list of <a class="reference internal" href="#horizon.workflows.Step" title="horizon.workflows.Step"><tt class="xref py py-class docutils literal"><span class="pre">Step</span></tt></a> classes which serve as the
starting point for this workflow’s ordered steps. Defaults to an empty
list (<tt class="docutils literal"><span class="pre">[]</span></tt>).</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.finalize_button_name">
<tt class="descname">finalize_button_name</tt><a class="headerlink" href="#horizon.workflows.Workflow.finalize_button_name" title="Permalink to this definition">¶</a></dt>
<dd><p>The name which will appear on the submit button for the workflow’s
form. Defaults to <tt class="docutils literal"><span class="pre">"Save"</span></tt>.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.success_message">
<tt class="descname">success_message</tt><a class="headerlink" href="#horizon.workflows.Workflow.success_message" title="Permalink to this definition">¶</a></dt>
<dd><p>A string which will be displayed to the user upon successful completion
of the workflow. Defaults to
<tt class="docutils literal"><span class="pre">"{{</span> <span class="pre">workflow.name</span> <span class="pre">}}</span> <span class="pre">completed</span> <span class="pre">successfully."</span></tt></p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.failure_message">
<tt class="descname">failure_message</tt><a class="headerlink" href="#horizon.workflows.Workflow.failure_message" title="Permalink to this definition">¶</a></dt>
<dd><p>A string which will be displayed to the user upon failure to complete
the workflow. Defaults to <tt class="docutils literal"><span class="pre">"{{</span> <span class="pre">workflow.name</span> <span class="pre">}}</span> <span class="pre">did</span> <span class="pre">not</span> <span class="pre">complete."</span></tt></p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.depends_on">
<tt class="descname">depends_on</tt><a class="headerlink" href="#horizon.workflows.Workflow.depends_on" title="Permalink to this definition">¶</a></dt>
<dd><p>A roll-up list of all the <tt class="docutils literal"><span class="pre">depends_on</span></tt> values compiled from the
workflow’s steps.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.contributions">
<tt class="descname">contributions</tt><a class="headerlink" href="#horizon.workflows.Workflow.contributions" title="Permalink to this definition">¶</a></dt>
<dd><p>A roll-up list of all the <tt class="docutils literal"><span class="pre">contributes</span></tt> values compiled from the
workflow’s steps.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.template_name">
<tt class="descname">template_name</tt><a class="headerlink" href="#horizon.workflows.Workflow.template_name" title="Permalink to this definition">¶</a></dt>
<dd><p>Path to the template which should be used to render this workflow.
In general the default common template should be used. Default:
<tt class="docutils literal"><span class="pre">"horizon/common/_workflow.html"</span></tt>.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.entry_point">
<tt class="descname">entry_point</tt><a class="headerlink" href="#horizon.workflows.Workflow.entry_point" title="Permalink to this definition">¶</a></dt>
<dd><p>The slug of the step which should initially be active when the
workflow is rendered. This can be passed in upon initialization of
the workflow, or set anytime after initialization but before calling
either <tt class="docutils literal"><span class="pre">get_entry_point</span></tt> or <tt class="docutils literal"><span class="pre">render</span></tt>.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.redirect_param_name">
<tt class="descname">redirect_param_name</tt><a class="headerlink" href="#horizon.workflows.Workflow.redirect_param_name" title="Permalink to this definition">¶</a></dt>
<dd><p>The name of a parameter used for tracking the URL to redirect to upon
completion of the workflow. Defaults to <tt class="docutils literal"><span class="pre">"next"</span></tt>.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Workflow.object">
<tt class="descname">object</tt><a class="headerlink" href="#horizon.workflows.Workflow.object" title="Permalink to this definition">¶</a></dt>
<dd><p>The object (if any) which this workflow relates to. In the case of
a workflow which creates a new resource the object would be the created
resource after the relevant creation steps have been undertaken. In
the case of a workflow which updates a resource it would be the
resource being updated after it has been retrieved.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Workflow.add_error_to_step">
<tt class="descname">add_error_to_step</tt><big>(</big><em>message</em>, <em>slug</em><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.add_error_to_step" title="Permalink to this definition">¶</a></dt>
<dd><p>Adds an error to the workflow’s Step with the
specifed slug based on API issues. This is useful
when you wish for API errors to appear as errors on
the form rather than using the messages framework.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Workflow.finalize">
<tt class="descname">finalize</tt><big>(</big><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.finalize" title="Permalink to this definition">¶</a></dt>
<dd><p>Finalizes a workflow by running through all the actions in order
and calling their <tt class="docutils literal"><span class="pre">handle</span></tt> methods. Returns <tt class="docutils literal"><span class="pre">True</span></tt> on full success,
or <tt class="docutils literal"><span class="pre">False</span></tt> for a partial success, e.g. there were non-critical
errors. (If it failed completely the function wouldn’t return.)</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Workflow.format_status_message">
<tt class="descname">format_status_message</tt><big>(</big><em>message</em><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.format_status_message" title="Permalink to this definition">¶</a></dt>
<dd><p>Hook to allow customization of the message returned to the user
upon successful or unsuccessful completion of the workflow.</p>
<p>By default it simply inserts the workflow’s name into the message
string.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Workflow.get_absolute_url">
<tt class="descname">get_absolute_url</tt><big>(</big><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.get_absolute_url" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the canonical URL for this workflow.</p>
<p>This is used for the POST action attribute on the form element
wrapping the workflow.</p>
<p>For convenience it defaults to the value of
<tt class="docutils literal"><span class="pre">request.get_full_path()</span></tt> with any query string stripped off,
e.g. the path at which the workflow was requested.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Workflow.get_entry_point">
<tt class="descname">get_entry_point</tt><big>(</big><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.get_entry_point" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the slug of the step which the workflow should begin on.</p>
<p>This method takes into account both already-available data and errors
within the steps.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Workflow.get_step">
<tt class="descname">get_step</tt><big>(</big><em>slug</em><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.get_step" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the instantiated step matching the given slug.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Workflow.get_success_url">
<tt class="descname">get_success_url</tt><big>(</big><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.get_success_url" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns a URL to redirect the user to upon completion. By default it
will attempt to parse a <tt class="docutils literal"><span class="pre">success_url</span></tt> attribute on the workflow,
which can take the form of a reversible URL pattern name, or a
standard HTTP URL.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Workflow.handle">
<tt class="descname">handle</tt><big>(</big><em>request</em>, <em>context</em><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.handle" title="Permalink to this definition">¶</a></dt>
<dd><p>Handles any final processing for this workflow. Should return a boolean
value indicating success.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Workflow.is_valid">
<tt class="descname">is_valid</tt><big>(</big><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.is_valid" title="Permalink to this definition">¶</a></dt>
<dd><p>Verified that all required data is present in the context and
calls the <tt class="docutils literal"><span class="pre">validate</span></tt> method to allow for finer-grained checks
on the context data.</p>
</dd></dl>
<dl class="classmethod">
<dt id="horizon.workflows.Workflow.register">
<em class="property">classmethod </em><tt class="descname">register</tt><big>(</big><em>step_class</em><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.register" title="Permalink to this definition">¶</a></dt>
<dd><p>Registers a <a class="reference internal" href="#horizon.workflows.Step" title="horizon.workflows.Step"><tt class="xref py py-class docutils literal"><span class="pre">Step</span></tt></a> with the workflow.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Workflow.render">
<tt class="descname">render</tt><big>(</big><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.render" title="Permalink to this definition">¶</a></dt>
<dd><p>Renders the workflow.</p>
</dd></dl>
<dl class="classmethod">
<dt id="horizon.workflows.Workflow.unregister">
<em class="property">classmethod </em><tt class="descname">unregister</tt><big>(</big><em>step_class</em><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.unregister" title="Permalink to this definition">¶</a></dt>
<dd><p>Unregisters a <a class="reference internal" href="#horizon.workflows.Step" title="horizon.workflows.Step"><tt class="xref py py-class docutils literal"><span class="pre">Step</span></tt></a> from the workflow.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Workflow.validate">
<tt class="descname">validate</tt><big>(</big><em>context</em><big>)</big><a class="headerlink" href="#horizon.workflows.Workflow.validate" title="Permalink to this definition">¶</a></dt>
<dd><p>Hook for custom context data validation. Should return a boolean
value or raise <a class="reference internal" href="exceptions.html#horizon.exceptions.WorkflowValidationError" title="horizon.exceptions.WorkflowValidationError"><tt class="xref py py-class docutils literal"><span class="pre">WorkflowValidationError</span></tt></a>.</p>
</dd></dl>
</dd></dl>
</div>
<div class="section" id="steps">
<h2>Steps<a class="headerlink" href="#steps" title="Permalink to this headline">¶</a></h2>
<dl class="class">
<dt id="horizon.workflows.Step">
<em class="property">class </em><tt class="descclassname">horizon.workflows.</tt><tt class="descname">Step</tt><big>(</big><em>workflow</em><big>)</big><a class="headerlink" href="#horizon.workflows.Step" title="Permalink to this definition">¶</a></dt>
<dd><p>A step is a wrapper around an action which defines it’s context in a
workflow. It knows about details such as:</p>
<ul class="simple">
<li>The workflow’s context data (data passed from step to step).</li>
<li>The data which must be present in the context to begin this step (the
step’s dependencies).</li>
<li>The keys which will be added to the context data upon completion of the
step.</li>
<li>The connections between this step’s fields and changes in the context
data (e.g. if that piece of data changes, what needs to be updated in
this step).</li>
</ul>
<p>A <tt class="docutils literal"><span class="pre">Step</span></tt> class has the following attributes:</p>
<dl class="attribute">
<dt id="horizon.workflows.Step.action">
<tt class="descname">action</tt><a class="headerlink" href="#horizon.workflows.Step.action" title="Permalink to this definition">¶</a></dt>
<dd><p>The <a class="reference internal" href="#horizon.workflows.Action" title="horizon.workflows.Action"><tt class="xref py py-class docutils literal"><span class="pre">Action</span></tt></a> class which this step wraps.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Step.depends_on">
<tt class="descname">depends_on</tt><a class="headerlink" href="#horizon.workflows.Step.depends_on" title="Permalink to this definition">¶</a></dt>
<dd><p>A list of context data keys which this step requires in order to
begin interaction.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Step.contributes">
<tt class="descname">contributes</tt><a class="headerlink" href="#horizon.workflows.Step.contributes" title="Permalink to this definition">¶</a></dt>
<dd><p>A list of keys which this step will contribute to the workflow’s
context data. Optional keys should still be listed, even if their
values may be set to <tt class="docutils literal"><span class="pre">None</span></tt>.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Step.connections">
<tt class="descname">connections</tt><a class="headerlink" href="#horizon.workflows.Step.connections" title="Permalink to this definition">¶</a></dt>
<dd><p>A dictionary which maps context data key names to lists of callbacks.
The callbacks may be functions, dotted python paths to functions
which may be imported, or dotted strings beginning with <tt class="docutils literal"><span class="pre">"self"</span></tt>
to indicate methods on the current <tt class="docutils literal"><span class="pre">Step</span></tt> instance.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Step.before">
<tt class="descname">before</tt><a class="headerlink" href="#horizon.workflows.Step.before" title="Permalink to this definition">¶</a></dt>
<dd><p>Another <tt class="docutils literal"><span class="pre">Step</span></tt> class. This optional attribute is used to provide
control over workflow ordering when steps are dynamically added to
workflows. The workflow mechanism will attempt to place the current
step before the step specified in the attribute.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Step.after">
<tt class="descname">after</tt><a class="headerlink" href="#horizon.workflows.Step.after" title="Permalink to this definition">¶</a></dt>
<dd><p>Another <tt class="docutils literal"><span class="pre">Step</span></tt> class. This attribute has the same purpose as
<a class="reference internal" href="#horizon.workflows.Step.before" title="horizon.workflows.Step.before"><tt class="xref py py-meth docutils literal"><span class="pre">before()</span></tt></a> except that it will instead
attempt to place the current step after the given step.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Step.help_text">
<tt class="descname">help_text</tt><a class="headerlink" href="#horizon.workflows.Step.help_text" title="Permalink to this definition">¶</a></dt>
<dd><p>A string of simple help text which will be prepended to the <tt class="docutils literal"><span class="pre">Action</span></tt>
class’ help text if desired.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Step.template_name">
<tt class="descname">template_name</tt><a class="headerlink" href="#horizon.workflows.Step.template_name" title="Permalink to this definition">¶</a></dt>
<dd><p>A path to a template which will be used to render this step. In
general the default common template should be used. Default:
<tt class="docutils literal"><span class="pre">"horizon/common/_workflow_step.html"</span></tt>.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Step.has_errors">
<tt class="descname">has_errors</tt><a class="headerlink" href="#horizon.workflows.Step.has_errors" title="Permalink to this definition">¶</a></dt>
<dd><p>A boolean value which indicates whether or not this step has any
errors on the action within it or in the scope of the workflow. This
attribute will only accurately reflect this status after validation
has occurred.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Step.slug">
<tt class="descname">slug</tt><a class="headerlink" href="#horizon.workflows.Step.slug" title="Permalink to this definition">¶</a></dt>
<dd><p>Inherited from the <tt class="docutils literal"><span class="pre">Action</span></tt> class.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Step.name">
<tt class="descname">name</tt><a class="headerlink" href="#horizon.workflows.Step.name" title="Permalink to this definition">¶</a></dt>
<dd><p>Inherited from the <tt class="docutils literal"><span class="pre">Action</span></tt> class.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Step.permissions">
<tt class="descname">permissions</tt><a class="headerlink" href="#horizon.workflows.Step.permissions" title="Permalink to this definition">¶</a></dt>
<dd><p>Inherited from the <tt class="docutils literal"><span class="pre">Action</span></tt> class.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Step.add_error">
<tt class="descname">add_error</tt><big>(</big><em>message</em><big>)</big><a class="headerlink" href="#horizon.workflows.Step.add_error" title="Permalink to this definition">¶</a></dt>
<dd><p>Adds an error to the Step based on API issues.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Step.contribute">
<tt class="descname">contribute</tt><big>(</big><em>data</em>, <em>context</em><big>)</big><a class="headerlink" href="#horizon.workflows.Step.contribute" title="Permalink to this definition">¶</a></dt>
<dd><p>Adds the data listed in <tt class="docutils literal"><span class="pre">contributes</span></tt> to the workflow’s shared
context. By default, the context is simply updated with all the data
returned by the action.</p>
<p>Note that even if the value of one of the <tt class="docutils literal"><span class="pre">contributes</span></tt> keys is
not present (e.g. optional) the key should still be added to the
context with a value of <tt class="docutils literal"><span class="pre">None</span></tt>.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Step.get_help_text">
<tt class="descname">get_help_text</tt><big>(</big><big>)</big><a class="headerlink" href="#horizon.workflows.Step.get_help_text" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the help text for this step.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Step.get_id">
<tt class="descname">get_id</tt><big>(</big><big>)</big><a class="headerlink" href="#horizon.workflows.Step.get_id" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the ID for this step. Suitable for use in HTML markup.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Step.prepare_action_context">
<tt class="descname">prepare_action_context</tt><big>(</big><em>request</em>, <em>context</em><big>)</big><a class="headerlink" href="#horizon.workflows.Step.prepare_action_context" title="Permalink to this definition">¶</a></dt>
<dd><p>Allows for customization of how the workflow context is passed to the
action; this is the reverse of what “contribute” does to make the
action outputs sane for the workflow. Changes to the context are not
saved globally here. They are localized to the action.</p>
<p>Simply returns the unaltered context by default.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Step.render">
<tt class="descname">render</tt><big>(</big><big>)</big><a class="headerlink" href="#horizon.workflows.Step.render" title="Permalink to this definition">¶</a></dt>
<dd><p>Renders the step.</p>
</dd></dl>
</dd></dl>
</div>
<div class="section" id="actions">
<h2>Actions<a class="headerlink" href="#actions" title="Permalink to this headline">¶</a></h2>
<dl class="class">
<dt id="horizon.workflows.Action">
<em class="property">class </em><tt class="descclassname">horizon.workflows.</tt><tt class="descname">Action</tt><big>(</big><em>request</em>, <em>context</em>, <em>*args</em>, <em>**kwargs</em><big>)</big><a class="headerlink" href="#horizon.workflows.Action" title="Permalink to this definition">¶</a></dt>
<dd><p>An <tt class="docutils literal"><span class="pre">Action</span></tt> represents an atomic logical interaction you can have with
the system. This is easier to understand with a conceptual example: in the
context of a “launch instance” workflow, actions would include “naming
the instance”, “selecting an image”, and ultimately “launching the
instance”.</p>
<p>Because <tt class="docutils literal"><span class="pre">Actions</span></tt> are always interactive, they always provide form
controls, and thus inherit from Django’s <tt class="docutils literal"><span class="pre">Form</span></tt> class. However, they
have some additional intelligence added to them:</p>
<ul class="simple">
<li><tt class="docutils literal"><span class="pre">Actions</span></tt> are aware of the permissions required to complete them.</li>
<li><tt class="docutils literal"><span class="pre">Actions</span></tt> have a meta-level concept of “help text” which is meant to be
displayed in such a way as to give context to the action regardless of
where the action is presented in a site or workflow.</li>
<li><tt class="docutils literal"><span class="pre">Actions</span></tt> understand how to handle their inputs and produce outputs,
much like <tt class="xref py py-class docutils literal"><span class="pre">SelfHandlingForm</span></tt> does now.</li>
</ul>
<p><tt class="docutils literal"><span class="pre">Action</span></tt> classes may define the following attributes in a <tt class="docutils literal"><span class="pre">Meta</span></tt>
class within them:</p>
<dl class="attribute">
<dt id="horizon.workflows.Action.name">
<tt class="descname">name</tt><a class="headerlink" href="#horizon.workflows.Action.name" title="Permalink to this definition">¶</a></dt>
<dd><p>The verbose name for this action. Defaults to the name of the class.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Action.slug">
<tt class="descname">slug</tt><a class="headerlink" href="#horizon.workflows.Action.slug" title="Permalink to this definition">¶</a></dt>
<dd><p>A semi-unique slug for this action. Defaults to the “slugified” name
of the class.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Action.permissions">
<tt class="descname">permissions</tt><a class="headerlink" href="#horizon.workflows.Action.permissions" title="Permalink to this definition">¶</a></dt>
<dd><p>A list of permission names which this action requires in order to be
completed. Defaults to an empty list (<tt class="docutils literal"><span class="pre">[]</span></tt>).</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Action.help_text">
<tt class="descname">help_text</tt><a class="headerlink" href="#horizon.workflows.Action.help_text" title="Permalink to this definition">¶</a></dt>
<dd><p>A string of simple help text to be displayed alongside the Action’s
fields.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.Action.help_text_template">
<tt class="descname">help_text_template</tt><a class="headerlink" href="#horizon.workflows.Action.help_text_template" title="Permalink to this definition">¶</a></dt>
<dd><p>A path to a template which contains more complex help text to be
displayed alongside the Action’s fields. In conjunction with
<a class="reference internal" href="#horizon.workflows.Action.get_help_text" title="horizon.workflows.Action.get_help_text"><tt class="xref py py-meth docutils literal"><span class="pre">get_help_text()</span></tt></a> method you can
customize your help text template to display practically anything.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Action.add_error">
<tt class="descname">add_error</tt><big>(</big><em>message</em><big>)</big><a class="headerlink" href="#horizon.workflows.Action.add_error" title="Permalink to this definition">¶</a></dt>
<dd><p>Adds an error to the Action’s Step based on API issues.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Action.get_help_text">
<tt class="descname">get_help_text</tt><big>(</big><em>extra_context=None</em><big>)</big><a class="headerlink" href="#horizon.workflows.Action.get_help_text" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the help text for this step.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.Action.handle">
<tt class="descname">handle</tt><big>(</big><em>request</em>, <em>context</em><big>)</big><a class="headerlink" href="#horizon.workflows.Action.handle" title="Permalink to this definition">¶</a></dt>
<dd><p>Handles any requisite processing for this action. The method should
return either <tt class="docutils literal"><span class="pre">None</span></tt> or a dictionary of data to be passed to
<a class="reference internal" href="#horizon.workflows.Step.contribute" title="horizon.workflows.Step.contribute"><tt class="xref py py-meth docutils literal"><span class="pre">contribute()</span></tt></a>.</p>
<p>Returns <tt class="docutils literal"><span class="pre">None</span></tt> by default, effectively making it a no-op.</p>
</dd></dl>
</dd></dl>
</div>
<div class="section" id="workflowview">
<h2>WorkflowView<a class="headerlink" href="#workflowview" title="Permalink to this headline">¶</a></h2>
<dl class="class">
<dt id="horizon.workflows.WorkflowView">
<em class="property">class </em><tt class="descclassname">horizon.workflows.</tt><tt class="descname">WorkflowView</tt><a class="headerlink" href="#horizon.workflows.WorkflowView" title="Permalink to this definition">¶</a></dt>
<dd><p>A generic class-based view which handles the intricacies of workflow
processing with minimal user configuration.</p>
<dl class="attribute">
<dt id="horizon.workflows.WorkflowView.workflow_class">
<tt class="descname">workflow_class</tt><a class="headerlink" href="#horizon.workflows.WorkflowView.workflow_class" title="Permalink to this definition">¶</a></dt>
<dd><p>The <a class="reference internal" href="#horizon.workflows.Workflow" title="horizon.workflows.Workflow"><tt class="xref py py-class docutils literal"><span class="pre">Workflow</span></tt></a> class which this view handles.
Required.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.WorkflowView.template_name">
<tt class="descname">template_name</tt><a class="headerlink" href="#horizon.workflows.WorkflowView.template_name" title="Permalink to this definition">¶</a></dt>
<dd><p>The template to use when rendering this view via standard HTTP
requests. Required.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.WorkflowView.ajax_template_name">
<tt class="descname">ajax_template_name</tt><a class="headerlink" href="#horizon.workflows.WorkflowView.ajax_template_name" title="Permalink to this definition">¶</a></dt>
<dd><p>The template to use when rendering the workflow for AJAX requests.
In general the default common template should be used. Defaults to
<tt class="docutils literal"><span class="pre">"horizon/common/_workflow.html"</span></tt>.</p>
</dd></dl>
<dl class="attribute">
<dt id="horizon.workflows.WorkflowView.context_object_name">
<tt class="descname">context_object_name</tt><a class="headerlink" href="#horizon.workflows.WorkflowView.context_object_name" title="Permalink to this definition">¶</a></dt>
<dd><p>The key which should be used for the workflow object in the template
context. Defaults to <tt class="docutils literal"><span class="pre">"workflow"</span></tt>.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.WorkflowView.get">
<tt class="descname">get</tt><big>(</big><em>request</em>, <em>*args</em>, <em>**kwargs</em><big>)</big><a class="headerlink" href="#horizon.workflows.WorkflowView.get" title="Permalink to this definition">¶</a></dt>
<dd><p>Handler for HTTP GET requests.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.WorkflowView.get_context_data">
<tt class="descname">get_context_data</tt><big>(</big><em>**kwargs</em><big>)</big><a class="headerlink" href="#horizon.workflows.WorkflowView.get_context_data" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the template context, including the workflow class.</p>
<p>This method should be overridden in subclasses to provide additional
context data to the template.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.WorkflowView.get_initial">
<tt class="descname">get_initial</tt><big>(</big><big>)</big><a class="headerlink" href="#horizon.workflows.WorkflowView.get_initial" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns initial data for the workflow. Defaults to using the GET
parameters to allow pre-seeding of the workflow context values.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.WorkflowView.get_template_names">
<tt class="descname">get_template_names</tt><big>(</big><big>)</big><a class="headerlink" href="#horizon.workflows.WorkflowView.get_template_names" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the template name to use for this request.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.WorkflowView.get_workflow">
<tt class="descname">get_workflow</tt><big>(</big><big>)</big><a class="headerlink" href="#horizon.workflows.WorkflowView.get_workflow" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the instanciated workflow class.</p>
</dd></dl>
<dl class="method">
<dt id="horizon.workflows.WorkflowView.post">
<tt class="descname">post</tt><big>(</big><em>request</em>, <em>*args</em>, <em>**kwargs</em><big>)</big><a class="headerlink" href="#horizon.workflows.WorkflowView.post" title="Permalink to this definition">¶</a></dt>
<dd><p>Handler for HTTP POST requests.</p>
</dd></dl>
</dd></dl>
</div>
</div>
</div>
</div>
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<h3><a href="../index.html">Table Of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#">Horizon Workflows</a><ul>
<li><a class="reference internal" href="#workflows">Workflows</a></li>
<li><a class="reference internal" href="#steps">Steps</a></li>
<li><a class="reference internal" href="#actions">Actions</a></li>
<li><a class="reference internal" href="#workflowview">WorkflowView</a></li>
</ul>
</li>
</ul>
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