abdus

Extending Template-Field contexts to increase field reuse

Recommended Posts

Based on this forum post, I wanted to find a more elegant solution for changing a field's settings per template. Hooking the page editor after it generates the form works and may still be needed for more complex modifications. But using field & template context, it's easier to modify the field settings and it greatly reduces the need for creating an almost identical field just to adjust a few things.

In my blog post, I've written on how to extend contextual options to allow any fieldtype / inputfield settings to be changed depending on the template. Hope you find it useful, and if you have any questions or comments, feel free to post them here.

https://abdus.co/blog/doing-more-with-fewer-fields-in-processwire/

  • Like 14

Share this post


Link to post
Share on other sites

very interesting article and very well put together.

i'm wondering why for example the maxfiles setting for images fields is not activated by default for template context. any ideas on this?

  • Like 1

Share this post


Link to post
Share on other sites

From @ryan in this blog post

Quote

But thus far, it has been limited to predefined properties: field label, description, visibility, column width, and required state. I've been reluctant to go further than that, because I think there's a fine line between what's useful and what's problematic here. Taken too far, you could easily end up with a confusing mess. Ultimately, the best ones to determine what's useful for field/template context and what's not, are the developers of Fieldtypes and Inputfields. 

 

  • Like 1

Share this post


Link to post
Share on other sites

yeah, he is the developer of the images fieldtype... so the question is why he thinks it would be bad to handle allowed extensions and maxfile settings in a template context?!

Share this post


Link to post
Share on other sites
1 minute ago, bernhard said:

yeah, he is the developer of the images fieldtype... so the question is why he thinks it would be bad to handle allowed extensions and maxfile settings in a template context?!

Personal preference, I should think, but he also gave us (well, those of us skilled enough to take advantage) the tools to change that behaviour. ^-^

  • Like 1

Share this post


Link to post
Share on other sites

Hi @abdus,

Do you know if it's possible to use this technique to add config fields such as minWidth and maxWidth to the template context for InputfieldImage? My first attempt isn't working:

// Add more image config fields to template context
$this->addHookMethod('InputfieldImage::getConfigAllowContext', function (HookEvent $e) {
    $allowables = ['minWidth', 'minHeight', 'maxWidth', 'maxHeight'];
    $e->return = array_merge($e->return, $allowables);
});

I have a feeling that the reason this doesn't work is because those config fields are inside a fieldset. Adding the whole fieldset would be fine, but the problem is that the fieldset doesn't have a name to add to getConfigAllowContext().

Any ideas?

-----

EDIT: have sussed it out. I used another hook to give names to those fieldsets.

// Give names to image config fieldsets
$wire->addHookAfter('InputfieldImage::getConfigInputfields', function(HookEvent $event) {
    /* @var InputfieldWrapper $wrapper */
    $wrapper = $event->return;
    $f = $wrapper->getChildByName('maxWidth');
    $fieldset = $f->parent;
    $fieldset->name = 'maxDimensions';
    $f = $wrapper->getChildByName('minWidth');
    $fieldset = $f->parent;
    $fieldset->name = 'minDimensions';
});

// Add more image config fields to template context
$this->addHookMethod('InputfieldImage::getConfigAllowContext', function (HookEvent $e) {
    $allowables = ['maxDimensions', 'minDimensions'];
    $e->return = array_merge($e->return, $allowables);
});

 

  • Like 7

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By MoritzLost
      This will be more of a quick tip, and maybe obvious to many of you, but it's a technique I found very useful when building display options. By display options I mean fields that control how parts of the page are displayed on the frontend, for example background colors, sizing, spacing and alignment of certain elements. I'll also touch on how to make those options intuitive and comfortable to use for clients.
      It basically involves setting up option values that can be used directly in CSS classes or as HTML elements and mapping those to CSS styling (which can be quickly generated in a couple of lines using a pre-processor such as SASS). Another important aspect is to keep the option values seperate from their corresponding labels; the former can be technical, the latter should be semantically meaningful. The field type that lends itself to this this seperation of concerns is the Selectable Options field, the following examples mostly use this field type. Note that this module is part of the ProcessWire core, but not installed by default.
      The following examples all come from real projects I built (though some are slightly modified to better demonstrate the principle).
      #1: Headline levels & semantics
      For a project that had many pages with long texts, I used a Repeater field to represent sections of text. Each section has a headline. Those sections may have a hierarchical order, so I used a Selectable Option field to allow setting the headline level for each section (you can guess where this is going). The definition of the options looks something like this (those are all in the format value|label, with each line representing one option, see the blogpost above for details):
      h2|Section headline h3|Sub-section headline Of course, the PHP code that generates the corresponding HTML can use those values :
      // "sections" is the repeater field foreach ($page->sections as $section) { // create an h2 / h3 tag depending on the selected option (called headline_level here) echo "<{$section->headline_level->value}>{$section->headline}</{$section->headline_level->value}>"; echo $section->body; } That's a pretty obvious example, but there are two important takeaways:
      I only used two options. Just because there are six levels of headlines in HTML, doesn't mean those are all relevant to the client. The less options there are, the easier it is to understand them, so only the options that are relevant should be provided. In this case, the client had provided detailed, structured documents containing his articles, so I could determine how many levels of hierarchy were actually needed. I also started at h2, since there should be only one h1 per page, so that became it's own field separate from the repeater. The two options have a label that is semantically relevant to the client. It's much easier for a client who doesn't know anything about HTML to understand the options "Section headline" and "Sub-section headline" than "h2" and "h3". Sure, it can be cleared up in the field description, but this way it goes from something that's quickly explained to something that needs no explanation at all. #2: Image width and SASS
      In the same project, there was also an image section; in our layout, some images spanned the entire width of the text body, others only half of it. So again, I created an options field:
      50|Half width 100|Full width In this case, I expected the client to request different sizes at some point, so I wanted it to be extensible. Of course, the values could be used to generate inline styles, but that's not a very clean solution (since inline styled break the cascade, and it's not semantic as HTML should be). Instead, I used it to create a class (admittedly, this isn't strictly semantic as well):
      <img src="..." class="w-<?= $section->image_width->value ?>"> With pure CSS, the amount of code needed to write out those class definitions will increase linearly with the number of options. In SASS however, you only need a couple of lines:
      @each $width in (50, 100) { .w-#{$width}{ max-width: percentage($width/100); } } This way, if you ever need to add other options like 25% or 75%, you only need to add those numbers to the list in parenthesis and you're done. You can even put the definition of the list in a variable that's defined in a central variables.scss file. Something like this also exists in Bootstrap 4 as a utility, by the way.
      It also becomes easier to modifiy those all at once. For example, if you decide all images should be full-width on mobile, you only need to add that once, no need to throw around !important's or modify multiple CSS definitions (this is also where the inline styles approach would break down) :
      # _variables.scss $image-widths: (25, 50, 75, 100); $breakpoint-mobile: 576px; # _images.scss @import "variables"; @each $width in $image-widths { .w-#{$width}{ max-width: percentage($width/100); @media (max-width: $breakpoint-mobile) { max-width: 100%; } } } One important gotcha: It might be tempting to just use an integer field with allowed values between 10 - 100. In fact, the amount of SASS code would be identical with a @for-directive to loop throuh the numbers. But that's exactly what makes point-and-click page builders so terrible for clients: too many options. No client wants to manually set numerical values for size, position and margins for each and every element (looking at you, Visual Composer). In fact, having too many options makes it much harder to create a consistent layout. So in those cases, less is more.
      #3: Multiple options in one field
      Another example for repeatable page sections, this time for a two-column layout. The design included multiple variants regarding column-span and alignment. Using a 12-column grid, we needed a 6-6 split, a centered 5-5 split, a left-aligned 6-4 split and a right-aligned 4-6 split. I didn't want to litter the repeater items with options, so I decided to put both settings in one field (called something like Column layout) :
      center_6_6|6 / 6 (Centered) center_5_5|5 / 5 (Centered) left_6_4|6 / 4 (Left-aligned) right_4_6|4 / 6 (Right-aligned) As long as the value format is consistent, the individual options can be quickly extracted and applied in PHP:
      [$alignment, $width['left'], $width['right']] = explode('_', $section->column_layout->value); echo '<section class="row justify-content-' . $alignment . '">'; foreach (['left', 'right'] as $side) { echo '<div class="col-lg-' . $width[$side] . '">'; echo $section->get("body_{$side}"); echo '</div>'; } echo '</section>'; If you don't recognize the syntax in the first line, it's symmetric array destructuring, introduced in PHP 7.1. For older versions you can use list() instead. This example uses Bootstrap 4 grid classes and flexbox utility classes for alignment. The corresponding CSS can be quickly generated in SASS as well, check the Bootstrap source code for a pointer.
      Again, I'm limiting the options to what is actually needed, while keeping it extensible. With this format, I can easily add other column layouts without having to touch the code at all.
      #4: Sorting page elements
      A final example. In this case I was working on a template for reference projects that had three main content sections in the frontend: A project description, an image gallery and embedded videos (each using their own set of fields). The client requested an option to change the order in which those sections appeared on the page. Had I known this earlier, I maybe would have gone for a Repeater Matrix approach once again, but that would have required restructuring all the fields (and the corresponding code), so instead I used a Selectable Option field (labelled "Display order"). My approach is similar to the one from the last example:
      body_gallery_embeds|Description - Gallery - Videos body_embeds_gallery|Description - Videos - Gallery gallery_body_embeds|Gallery - Description - Videos gallery_embeds_body|Gallery - Videos - Description embeds_body_gallery|Videos - Description - Gallery embeds_gallery_body|Videos - Gallery - Description Since there are six possibilities to sort three items, this is the expected number of options. So I decided to include them all, even though some are probably never going to be used. I also tried to use a predictable order for the options (i.e. the options come in pairs, depending on what element is first). And here is the code used on the frontend:
      // render the template files for each section and store the result in an associative array $contents = [ 'body' => wireRenderFile('partials/_section-body.php', $page), 'gallery' => wireRenderFile('partials/_section-gallery.php', $page), 'embeds' => wireRenderFile('partials/_section-embeds.php', $page), ]; // e.g. 'gallery_body_embeds' => ['gallery', 'body', 'embeds']; $order = explode('_', $page->display_order->value); // echo the contents in the order defined by the option value foreach ($order as $item) { echo $contents[$item]; } You can see how it will be easy to add an additional section and integrate it into the existing solution. Though a fourth item would result in 4! = 24 possibilities to sort them, so at that point I'd talk to my client about which layouts they actually need 🙂
      Conclusion
      I always try to keep my code and the interfaces I create with ProcessWire extensible and intuitive. Those are a couple of solutions I came up with for projects at work. They are certainly not the only approach, and there is nothing super special about those examples, but I found that putting a little more effort into defining options with meaningful labels and using option values that I can use directly in my templates makes the result less verbose and more maintainable. Some or most of this tutorial may be immediately obvious to you, but if you made it this far, hopefully you got something out of it 🙂
      Feel free to share your own methods to create display options, or how you would've approached those problems differently. Thanks for reading!
    • By Marcel
      Hey all,
      I want to customize the mywebsite/processwire/profile page. It's almost all good but I want to get rid of the sections 'Admin Theme' and 'Language' so that the user can just set a new password. (see image)
      Do I have to modify the admin template or how can I do that? Because when I go tree>Admin>Profile there are no fields to add or remove.
      Or where can I find the php file?
      I would appreciate your help.

    • By JanPavelka
      Hi guys, I'm new here.
      I created custom field impressum_text in Processwire and now I need display this field in my theme. How can I please display this custom field in my theme (in file _main.php)?
      Can you help me, please?
      Thank you!
       

    • By dweeda
      How do I migrate a template with all its fields and values to a new site? Is their an export/import process?
    • By rareyush
      I am using module "FormTemplateProcessor" to get data in a pages but they all are unpublished and when I am trying to display them with relevent pages it not working
       
      page1 p1 p2 p3 page2 (FormTemplateProcessor) up1 (unpublished page and have p1 id on field knows as "ID") up2 (unpublished page and have p3 id on field knows as "ID") up3 (unpublished page and have p2 id on field knows as "ID") now here
      up1, ip2, up3 can be created by p1, p2 or p3 and I am saving respectively I'm saving their id in field which is being used by up1,up2,up3, etc template.
       
      now I want to show the data from unpublished pages which belongs to p1, p2 and p3 respectively
       
       
      anyone has experienced this or knows something which can help me out ?