Migrate Wiki content: Extbase_und_Fluid_FAQ (#399)

* Migrate Wiki content: Extbase_und_Fluid_FAQ

http://wiki.typo3.org/Extbase_und_Fluid_FAQ
refs: TYPO3-Documentation/T3DocTeam#154

* Update Index.rst

* Updated section on dynamic array indexes

Documentation/Index.rst

@@ -87,13 +87,14 @@ Find out how to contact the Documentation Team in :ref:`Contact Us <h2document:c
 
    a-CodingGuidelines/Index
    b-ExtbaseReference/Index
+   c-FAQ/Index
    ViewHelper Reference    ➜  <https://docs.typo3.org/typo3cms/ViewHelperReference/>
 
 .. toctree::
    :hidden:
    :caption: ABOUT
 
-   GenIndex
+   genindex
    Sitemap/Index
    About
    Targets

Documentation/c-FAQ/Index.rst

@@ -0,0 +1,292 @@
+.. include:: /Includes.rst.txt
+.. _faq_extbase_fluid:
+
+=====================
+Extbase und Fluid FAQ
+=====================
+
+Extbase
+=======
+
+How can I change the actions of a plugin via TypoScript?
+--------------------------------------------------------
+
+To define which controller/action pairs belong to a plugin and which
+actions are not cacheable, you should always use
+:php:`ExtensionUtility::configurePlugin`. However, you can
+override the order of actions via TypoScript but you can't define
+non-cacheable actions or add new Controllers that way!
+
+How can I specify a storage Pid for my plugins?
+-----------------------------------------------
+
+You can specify a global storage Pid for all plugins of your extension
+in your TypoScript setup like this:
+
+.. code-block:: ts
+
+   plugin.tx_yourextension {
+       persistence {
+           storagePid = 123
+       }
+   }
+
+To set it only for one plugin, replace :ts:`tx_yourextension` by
+:ts:`tx_yourextension_yourplugin`. For modules it's the same syntax:
+
+.. code-block:: ts
+
+   module.tx_yourextension {
+       persistence {
+           storagePid = 123
+       }
+   }
+
+What is the "Extension Name"?
+-----------------------------
+
+These are the Extbase naming conventions:
+
+Extension key
+   blog_example (= $_EXTKEY)
+
+Extension name
+   BlogExample (used e.g. in class names)
+
+Plugin name
+   MyPlugin
+
+Plugin key
+   myplugin (lowercase, no underscores)
+
+Plugin signature
+   blog_example_myplugin (used in TypoScript, TCA)
+
+Plugin namespace
+   tx_blogexample_myplugin (used to namespace GET/POST vars)
+
+
+Fluid
+=====
+
+How can I comment out parts of my Fluid template?
+-------------------------------------------------
+
+As the Fluid syntax is basically XML, you can use CDATA tags to comment
+out parts of your template:
+
+.. code-block:: xml
+
+   <![CDATA[
+   This will be ignored by the Fluid parser
+   ]]>
+
+If you want to hide the contents from the browser, you can additionally
+encapsulate the part in HTML comments:
+
+
+.. code-block:: xml
+
+   <!--<![CDATA[
+   This will be ignored by the Fluid parser and by the browser
+   ]]>-->
+
+Note: This way the content will still be transfered to the browser! If
+you want to completely skip parts of your template, you can make use of
+the **f:comment** view helper. To disable parsing you best combine it
+with CDATA tags:
+
+
+.. code-block:: xml
+
+   <f:comment><![CDATA[
+   This will be ignored by the Fluid parser and won't appear in the source code of the rendered template
+   ]]></f:comment>
+
+How can I use JavaScript inside Fluid templates?
+------------------------------------------------
+
+Since Fluid & JavaScript are using JSON syntax, you should always wrap
+inline scripts with CDATA tags (see above). If you want to access Fluid
+variables from your scripts, you should instantiate them on top of your
+script block like:
+
+
+.. code-block:: xml
+
+   <script type="text/javascript">
+   var someSetting = "{settings.someSetting}";
+   /* <![CDATA[ */
+     alert(someSetting);
+   /* ]]> */
+   </script>
+
+But - if possible - it's even better to extract your scripts to external
+files!
+
+How can I get translated validation error messages?
+---------------------------------------------------
+
+There will be support for localized error labels at some point.
+Currently you can use the error code in order to output the error
+message in the current language. See `Translated validation error
+messages for Fluid <translated-validation-error-messages-for-fluid>`__.
+
+How can I render localized dates?
+---------------------------------
+
+Similar to the localized error messages, you can put date formats in
+your locallang files:
+
+
+.. code-block:: code
+
+      [...]
+          <label index="culture.date.formatLong">Y-m-d H:i</label>
+          <label index="culture.date.formatShort">Y-m-d</label>
+      [...]
+
+And then just refer to them in your fluid template: <HTML> {post.date ->
+f:format.date(format: '{f:translate(key:
+\\'culture.date.formatShort\')}')} </HTML>
+
+If you want to use names for months, you can do so like this: locallang:
+
+
+.. code-block:: code
+
+   ::
+
+      [...]
+          <label index="culture.monthNames.1">january</label>
+          <label index="culture.monthNames.2">february</label>
+      [...]
+
+Fluid:
+
+
+.. code-block:: xml
+
+   {post.date -> f:format.date(format: 'd.')}
+
+.. code-block:: xml
+
+   <f:translate key="culture.monthNames.{post.date -> f:format.date(format: 'n')}" />
+
+
+Can ViewHelpers be nested?
+--------------------------
+
+Yes:
+
+
+.. code-block:: xml
+
+   <f:format.date format="{f:translate(key: 'culture.date.formatShort')}">{post.date}</f:format.date>
+
+If you use the inline notation for the outer and the inner view helper,
+you'll have to take care of the correct escaping:
+
+
+.. code-block:: xml
+
+   {post.date -> f:format.date(format: '{f:translate(key: \'culture.date.formatShort\')}')}
+
+You can also use view helpers in array parameters:
+
+
+.. code-block:: xml
+
+   <f:translate key="someKey" arguments="{0: 'foo', 1: '{f:count(subject: items)}'}" />
+
+Another nested Example
+
+.. code-block:: xml
+
+   <f:translate key="text" htmlEscape="false" arguments="{0: '{f:translate(key: \'here\') -> f:link.action(action: \'show\')}'}" />
+
+
+
+.. code-block:: xml
+   :caption: File: locallang.xml
+
+   <label index="here">this link</label>
+   <label index="text">You can use %1$s to register.</label>
+
+The output will be a linked text: You can use **this link** to register.
+
+These are the escaping rules for quotes:
+
+-  Single quotes (') must be escaped with a single backslash, if
+   surrounded by a higher level single quote of the outer ViewHelper
+-  Single quotes within an escaped quote must be escaped, the number of
+   backslashes is @n*2 + 1@, with @n@ the number of backslashes of the
+   previous quotation
+
+How can I use dynamic array indexes?
+------------------------------------
+
+An array can be accessed dynamically by recursively inserting its index:
+
+.. code-block:: xml
+
+   <!-- Recursive variable resolving -->
+   <f:variable name="array" value="{0: 'foo', 1: 'bar'}" />
+   <f:variable name="index" value="1" />
+   Variable "index" contains the array position we need.
+   Dynamic array index #{index}: {array.{index}} <!-- bar -->
+   
+It is even possible to call variables dynamically that way:
+
+.. code-block:: xml
+   <f:variable name="typeOne" value="This is type 1" />
+   <f:variable name="typeTwo" value="This is type 2" />
+   <f:variable name="selectedType" value="Two" />
+   Variable "selectedType" is a string that's part of a variable name.
+   Dynamic named variable: {type{selectedType}} <!-- This is type 2 -->
+   
+See `Fluid supports variable access with dynamic names/parts of name 
+<https://twitter.com/NamelessCoder/status/937995733873184768>`__
+
+How can I use Fluid in my Email templates?
+------------------------------------------
+
+See `Send mail with FluidEmail <t3coreapi:send-mail-with-fluidemail>`__
+
+Can I compare strings with the if view helper?
+----------------------------------------------
+
+Starting from TYPO3 6.1 this is possible as expected and you can use
+constant strings in if view helper as follows:
+
+.. code-block:: xml
+
+   <f:if condition="{item.status} == 'active'"> Output something </f:if>
+
+
+Can I use the translate ViewHelper with FLUIDTEMPLATE
+-----------------------------------------------------
+
+By default the translate ViewHelper loads labels from the locallang file
+inside *Resources/Private/Language/* of the \*current extension*.
+FLUIDTEMPLATE uses the Standalone View of Fluid that is by default not
+bound to an extension. But you can specify the path to your locallang
+file as ViewHelper argument:
+
+.. code-block:: xml
+
+   <f:translate key="LLL:fileadmin/some/path/locallang.xlf:your.key" />
+
+Alternatively, if you put your locallang files inside an extension (the
+recommended way) you can tell the FLUIDTEMPLATE to use that extension by
+default:
+
+.. code-block:: ts
+
+   10 = FLUIDTEMPLATE
+   10.file = some/file
+   10.extbase.controllerExtensionName = YourExtension
+
+Now, using :xml:`<f:translate key="someKey" />` will resolve to translations
+from :file:`EXT:your_extension/Resources/Private/Language/locallang.xlf`.
+