Introduction to Fluid

Example Fluid snippet

This is how a simple Fluid snippet could look like:

<h4>This is your headline</h4>
<p>
    <f:if condition="{myExpression}">
        <f:then>
            {somevariable}
        </f:then>
        <f:else>
            {someothervariable}
        </f:else>
    </f:if>
</p>

The resulting HTML may look like this:

<h4>This is your headline</h4>
<p>This is the content of variable "somevariable"</p>

The above Fluid snippet contains:

ViewHelpers:

The XML elements that start with f: like <f:if> etc. are standard ViewHelpers. It is also possible to define custom ViewHelpers, for example <foo:bar foo="bar">. A corresponding file ViewHelpers/BarViewHelper.php with the methods initializeArguments and render contains the HTML generation logic. ViewHelpers are Fluid components which make a function call to PHP from inside of a template. TYPO3 adds some more ViewHelpers for TYPO3 specific functionality.

ViewHelpers can do simple processing such as remove spaces with the Spaceless ViewHelper <f:spaceless> ViewHelper or create a link as is done in the TYPO3 Fluid Viewhelper Link.page ViewHelper <f:link.page>.

Expressions, variables:

Fluid uses placeholders to fill content in specified areas in the template where the result is rendered when the template is evaluated. Content within braces (for example {somevariable}) can contain variables or expressions.

Conditions:

The conditions are supplied here by the If ViewHelper <f:if> ViewHelper.

Directory structure

In your extension, the following directory structure should be used for Fluid files:

This directory structure is the convention used by TYPO3. When using Fluid outside of TYPO3 you can use any folder structure you like.

If you are using Extbase controller actions in combination with Fluid, Extbase defines how files and directories should be named within these directories. Extbase uses sub directories located within the "Templates" directory to group templates by controller name and the filename of templates to correspond to a certain action on that controller.

If you don't use Extbase you can still use this convention, but it is not a requirement to use this structure to group templates into logical groups, such as "Page" and "Content" to group different types of templates.

In Fluid, the location of these paths is defined with \TYPO3Fluid\Fluid\Core\Rendering\RenderingContext->setTemplatePaths().

TYPO3 provides the possibility to set the paths using TypoScript.

<div class="header">
    <f:render section="Header" />
</div>
<div class="main">
    <f:render section="Main" />
</div>

<f:layout name="Default" />

<f:section name="Header">
    <!-- add header here ! -->
</f:section>

<f:section name="Main">
    <!-- add main content here ! -->
</f:section>

<b>Tags</b>:
<ul>
    <f:for each="{tags}" as="tag">
        <li>{tag}</li>
    </f:for>
</ul>

<f:render partial="Tags" arguments="{tags: post.tags}" />

Example: Using Fluid to create a theme

This example was taken from the example extension for TYPO3 site package tutorial and reduced to a very basic example.

The site package tutorial walks you through the creation of a site package (theme) using Fluid. In our simplified example, the overall structure of a page is defined by a layout "Default". We show an example of a three column layout. Further templates can be added later, using the same layout.

Set the Fluid paths with TypoScript using FLUIDTEMPLATE

lib.dynamicContent = COA
lib.dynamicContent {
  10 = LOAD_REGISTER
  10.colPos.cObject = TEXT
  10.colPos.cObject {
    field = colPos
    ifEmpty.cObject = TEXT
    ifEmpty.cObject {
      value.current = 1
      ifEmpty = 0
    }
  }
  20 = CONTENT
  20 {
    table = tt_content
    select {
      orderBy = sorting
      where = colPos={register:colPos}
      where.insertData = 1
    }
  }
  90 = RESTORE_REGISTER
}

page = PAGE
page {
  // Part 1: Fluid template section
  10 = FLUIDTEMPLATE
  10 {
    templateName = Default
    templateRootPaths {
      0 = EXT:site_package/Resources/Private/Templates/Page/
    }
    partialRootPaths {
      0 = EXT:site_package/Resources/Private/Partials/Page/
    }
    layoutRootPaths {
      0 = EXT:site_package/Resources/Private/Layouts/Page/
    }
  }
}

<f:render section="Header" />
<f:render section="Main" />
<f:render section="Footer" />

<f:layout name="Default"/>

<f:section name="Header">
    <!-- add header here ! -->
</f:section>

<f:section name="Main">
    <f:render partial="Jumbotron"/>
    <div class="container">
        <div class="row">
            <div class="col-md-4">
                <f:cObject typoscriptObjectPath="lib.dynamicContent"
                           data="{colPos: '1'}"/>
            </div>
            <div class="col-md-4">
                <f:cObject typoscriptObjectPath="lib.dynamicContent"
                           data="{colPos: '0'}"/>
            </div>
            <div class="col-md-4">
                <f:cObject typoscriptObjectPath="lib.dynamicContent"
                           data="{colPos: '2'}"/>
            </div>
        </div>
    </div>
</f:section>

<f:section name="Footer">
    <!-- add footer here ! -->
</f:section>

• The template uses the layout "Default". It must then define all sections that the layout requires: "Header", "Main" and "Footer".
• In the section "Main", a partial "Jumbotron" is used.
• The template makes use of column positions (colPos). The content elements for each section on the page will be rendered into the correct div. Find out more about this in Backend layout.
• Again, we are using Object Accessors to access data (e.g. {colPos: '2'}) that has been generated elsewhere.

<div class="jumbotron">
    <div class="container">
        <h1 class="display-3">Hello, world!</h1>
        <p> some text </p>
    </div>
</div>