[FEATURE] <f:contains> ViewHelper

[staatzstreich]

This patch adds a new <f:contains> ViewHelper to Fluid, which allows
to check if a provided string or array contains a specified value.
Depending on the input, this mimicks PHP's in_array() or str_contains().

The initial version of this patch is intended to be backported to Fluid 4.
In a follow-up, the code and argument types can be improved for Fluid 5.

Resolves: #1125

[mbrodala]

I wonder if we should consider extending conditions instead, e.g. using Symfony EL:

{myString contains "foo"}

Then we'd not need to add a viewhelper for each and every bit of functionality.

[s2b]

@mbrodala I agree that we should improve conditions overall. However, in the short term it's probably wise to add ViewHelpers for the most common use cases nonetheless. Also, the following syntax is already possible:

<f:if condition="{f:contains(value: 'foo', array: myArray)} && ...">

[s2b]

The more I think about it, the more I struggle with the VH API. I'm open to other suggestions, but these come to mind:

• Allow both array and string as one argument and differentiate in the VH based on the type
• Split into two: f:contains for strings and f:in for arrays

What do you think?

[brotkrueml]

• Split into two: f:contains for strings and f:in for arrays

IMHO there should be two dedicated view helpers as you suggested to handle the different types. Additionally, for an f:in view helper (better f:inArray as the purpose is clearer) we should think about the possibility for checking the type (like in_array in PHP with the "strict" argument):

<f:inArray value="some-value" array="{someArray}" strict="{true}">

With "strict" be false by default (like in PHP). Strictness might be difficult when setting a value directly in Fluid:

<f:inArray value="42" array="{someArray}" strict="{true}">

Here the value is a string while the array values might be ints. But that would work:

<f:inArray value="{someValue}" array="{someArray}" strict="{true}">

if {someValue} is passed to Fluid and is really an int.

[s2b]

Thank you for your input here! We discussed this again and we came to the conclusion that we will have one <f:contains> ViewHelper, although slightly differently than it's implemented here:

{myArray -> f:contains(value: 'foo')}
{f:contains(subject: myArray, value: 'foo')}
{myString -> f:contains(value: 'foo')}
{f:contains(subject: myString, value: 'foo')}

So the subject will support both string and array (+ array-like objects). I get the arguments for type strictness, but in my opinion, convenience and consistent naming is more important in a template engine.

I'll adjust the implementation accordingly in the next few days.

[s2b]

I've adjusted the ViewHelper and documentation. WDYT?