add usage description of moose critics

moose-wiki/Users/moose-ide/moose-critics.md

@@ -7,13 +7,83 @@ subtitle: 'Create your own critics on model'
 toc: true
 ---
 
-WIP
+Moose Critics is a tool of MooseIDE that allows one to define a suite of rules to verify on software systems' models.
+It can be compared to a tool to create rules such as the one provided by [SonarQube](https://www.sonarsource.com/products/sonarqube/).
 
-## Open the Moose Critics Browser
+We first present how to use the UI to manipulate the tool. Then we present how to use it programmatically.
 
-## Create and Apply Rules
+## With the User Interface
 
-## Export and Import Rules
+The easiest way to manipulate the Critics Browser is to use its UI.
+
+### Open the Moose Critics Browser
+
+You can open the browser in the Menu under `Moose > Moose Critic Browser`.
+
+The browser is divided into three main panels.
+From left to right: the entities you are checking, the rules and context you want to check, and the computed violations.
+
+The entities panels (left) grouped the entities by their type.
+You can inspect any entity (or a group of entities) by double-clicking on its entry.
+
+> If you do not see entities, you might not have loaded any model and propagate entities.
+> Please consider reading MooseIDE documentation first.
+
+You can now create Rules and context for your rules
+
+### Create and Apply Rules
+
+Rules in MooseCritics are divided into two components: Context, and Condition.
+A context is a collection of entities to specify the scope of our analysis. Using this, we are only executing our rules on the relevant entities for them.
+This step is crucial for performance reasons.
+Once we have a context, we add conditions to it, to verify the validity of every entity belonging to this context.
+
+Let’s start building a few of those, to appreciate how easy and versatile this system can be!
+
+#### Create a context
+
+To create your first context, right-click on `Root context` and select `Add context` entry.
+It displays a panel in which you can specify the name of the context, an input, and the text summary (*a.k.a.,* description) of the context.
+
+The input block takes as input all the entities of the parent context (`root context` provides all the entities) and should return a collection of entities.
+
+For example, a context that would select all the methods would be filled with the following input block:
+
+```st
+[ :collection | collection select: [ :entity | entity isMethod ] ]
+```
+
+#### Create a rule
+
+Once you have created your context, you can create rules.
+To create your first rule, right-click on a context and select `Add condition` entry.
+As for context, rules are composed of a name, an input block, and a description.
+It also includes a severity level.
+
+This time, the input block will take as a parameter each element of the collection of entities provided by the parent context.
+The block should return a boolean: `true` when the entity violated the rule, otherwise, it returns `false`.
+
+For example, to retrieve the dead methods, we would fill it like this:
+
+```st
+[ :entity | entity isDeadMethod ]
+```
+
+### Run the critics
+
+Once the browser is configured, it is possible to execute the rules suite.
+To do so, simply press the `Run` button at the bottom right of the window.
+The right side panel will be filled with the entities that violated the rules.
+
+### Export and Import Rules
+
+When closing the window, the critic's suite will be removed from the system.
+However, it is possible to save it for future usage.
+
+To do so, we use the Ston format (similar to JSON but with support for complex object export).
+To export the result, you only have to click on the `Export rules` button and select the destination folder.
+
+The import is made the same way using the `Import rules` button.
 
 ## Use it programmatically