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I've been fiddling with the idea to add custom fields to my content objects for some time. Sometimes content items should consist of preset fields, header images that needs to adhere to a certain position, ie OVER the header, etc - with minimum need for client f*ckups.

The parameter system of J1.5 came to the rescue, and together with the ingenious override system, it's a match made in heaven.

Only one core hack is needed, and it's very easy to back up and transfer to the next upgrade


Core alterations:

File: administrator\components\com_content\models\article.xml - this is where the parameter fields gets made.

In the top of the advanced parameters block, add the following code:



This will yield the following fields inside the Advanced Parameters-tab when you edit content items:

(Norwegian language file)

- A text field parameter named "title_tag"
- A list where you can choose silly parameters, called "silly_options"
- A list that gets the .jpg files from the "images/stories/header-img" folder, called "article_image"
- A nice little spacer to make your custom fields more visible

Check out http://docs.joomla.org/Tutorial:Template_parameters#Standard_parameter_types_in_detail for a nice referral on the different parameter options available to us. Template params use the same system as content params.



Application examples:

Using beez as an example, open \templates\beez\html\com_content\article\default.php



This will check if the "article_image" property is set. If so, it adds a div with the image inside. This is really simple - in production I'd probably use some GD stuff to resize/crop the image. It's PHP, so your imagination is the limit.

The "silly_options" we made, could well be used to set a custom article template, be used as a article-class-suffix, etc. I'm sure you all see the possibilities.


Another simple core hack to use the "title_tag" parameter:

In this example, we cannot use the overrides - but it's a simple and portable alteration:

In \components\com_content\views\article\view.html.php, line 99, find:
$document->setTitle( $params->get( 'page_title' ) );

Replace it with:


It checks whether you've set the "title_tag" param, if so, uses it - and defaults to the ready-made one if not. Very simple, and a major step up from the 1.0 way.


I'm really eager to get some feedback on this. I feel it's a little step towards a more dynamic content class, which has been a wet dream of mine for some time. Ideally, I'd like to put my own params in their own tab, in their own db field, etc - but my coding skills are at best suited for reverse engineering. If somebody wants to pick it up and develop this further, I'll be very happy!

Hi Tobiasn

This is excellent and I think exactly what I need. I would like to assign a unique image to each article. Is it possible to assign it to a module position? I am a joomla newbie so I apologize in advance if the answer is obvious.

Thanks, Tina

Well, since it's effectively a part of the content item itself, it's not easy to assign it to a module position - it would be much easier to just place it inside the "default.php" override-file for com_content.

I guess you'e got an idea of overrides, if not - this is a nice introduction: http://docs.joomla.org/Understanding_Output_Overrides

I exemplified the case of the article image in the post above, using the beez template's override. The php and html stuff can be daunting at first, but the code I've used here is simple stuff. You can just copy the code over to your own project, but remember this:
- you need to decide on one folder where you will put the images
- there's no way of actually previewing the images automatically using this method - unless you want to dive into some serious coding
- you need to remember to include the full image path in the override

Good luck

Thanks for responding. I'll give it a try!

This is great stuff, I do have a question though. In the above example, with the created "silly Options" drop menu in the params. How would I go about coding something to show only if I chose a certain option. Say I choose the "Boja" option in my article setup and I want it to display some special text in the header of the article how would I code the default.php to say if "silly option/Boja" is selected, echo this?

Hey Brien, that's fairly easy, you check if the variable name contains the appropriate value .

Try this:

Say you want this applicable in every article's full view and you use the Beez template: you'll do this in \templates\beez\html\com_content\article\default.php

Thanks for the post, that is exactly what I was looking for, just didn't know how to write the == part. Thank you!!!

Is there a way to make a separate drop menu in the parameters section to put some personal parameters?

Yes, everything is there: http://docs.joomla.org/Tutorial:Template_parameters#Standard_parameter_types_in_detail

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Hi,

This is great, I was just looking for a way to do this.

The values are stored in the DB in jos_content.attribs.
The only problem is that the parameters do not have their individual columns.
So it makes it hard to query the database and get a list of all the articles where Grejer = Shaka, for example..

tobiasn - that's great and thanks for posting it. I'm doing this at the moment and have managed to create the article parameter quite easily, which appears in the form when creating a new article. It isn't, however, saved. How do I see to it that it's saved in the db?

hey tobaisn!

great post!

is there any way to call article parameters from a module...say, related items? i'm trying to customize related items so that it will also show the article's image.

thanks!

Hi Tobiasn,

Great tutorial .... Can it also do the following ?

The content belongs NOT ONLY to section & categories. But also to 'Product'. So to add a new content, I need to make a new drop down of 'Product' item, besides dropdown of section & category.

Questions :
- Must I add a new field in content table to hold the 'Product' item ? If yes, which table must I change ?
- Which other files must be edited to catch the value and store it to database ?

Any information will be helpful .... many thanks.
Best Regards,
- Jack -

this is awesome! thanks tobiasn!

im trying to modify this link reference in a module:


with something that would pick up a custom field from the article parameters - my question is how would i reference that custom field?

ie what could i replace <?php echo $item->link; ?> with?

thank you!

edit:

my process so far:

- added to article.xml


my question:

- how do i reference what is added to this field in a module so that it replaces the following link reference:

i am also finding it is not saved - does anyone know how to keep the field saved?

thank you!

EDIT: It is being saved now when i add it to the 'advanced parameters', and not just the 'article parameters'.

still dont know how to reference the field in a module - can anyone help?

thanks!

This looks like a useful hack - so, it's basically like adding a custom field to the article which can be displayed in the frontend?

Is there any way to use this hack in the frontend article submission form so that users can enter the custom field data?

There's a lot of people looking to add custom fields to the main joomla article content. I've been experimenting with this solution, but its very buggy:
viewtopic.php?f=428&t=352285

@rw1: I did some customization too, the difference is that I created these parameters under basic parameters and they are being saved (not sure if they're being saved to the db, but I'm able to retrieve them by just referencing them).


Referencing custom parameters is fairly easy. Let's say you've created parameter called dummy_text and you just want to echo the parameter, so to do it would be:


I hope this helps you guys.


Happy coding!
Caio

So it's possible to give values to these parameters via the content creation gui is it?

Do you mean when you're posting a new content (or editing an existing one) on the frontend? If this is it, I'm not sure if you can, but I don't see why you can't.

I didn't went that far creating custom parameters, all I did was custom parameters for the com_content on the backend to customize the layout for the "Category List Layout" (I've added the option to hide the '#' column, modified the date shown from creation to 'start publishing' date and added a time column which shows the 'starting publishing' time.

Now I'm playing with the original banners module to give the user (anyone who has backend access) an option to change the banners main folder (which is hard coded inside the mod_banners.php file) to any folder wanted. Later, I'll extend that and the user (that same one who has backend access. lol ) will be able to point separately for each file type (i.e. IMG > media/banners/images, SWF > media/banners/flash)



Happy coding,

Caio

Yes, i want the user to be able to enter a custom parameter into exactly the same form they use to create the content

@cehjohnson

I'll play with that later, because I also have the need to create a custom field, but I think this will be a bit harder because it will need to deal with the db.

Would be great if you could keep me informed thanks!

@cehjohnson:

I'll post here any progress I make, but I have to apologize, this will have to wait. I'm in the middle of a big (reeeally big!!!) task here at work.

Thx for your appreciation.



Happy coding,

Caio

Don't worry ;-) Best of luck :-)

Damn, it seems I can't get it to work...am I the only one?

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Will buckle down and get this hack sorted. Custom fields have always been double dutch to me, this seems a little easier to work through so thanks

nice...will give it a try soon..

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why not working for you? its not that easy to achieve but you should get there soon. stick to the guide.

Please describe what's happening...

Just to clarify things a little bit...


Creating custom parameters is indeed easy if you have some programming logics knowledge. Once you figure out the concept it's very easy to implement, but there are some custom parameters that might be harder to implement because it will require more then just echoing or you probably will break something (i.e. your template).


Happy Joomla!ing

Caio