Dependencies for $page->prev & $page->next methods?

[Mikel]

While building our recent project I discovered that I could not adress the siblings of a page with the mentioned methods. Neither do the methods getNext() or getPrev() work. Are there some hidden dependencies I am not aware of? Did not find anything in the docs...

To be precise:

    $g = $pages->find("template=glossary_detail");
    $prev = "<a href='{$page->prev($g)->url}'>prev</a> ";
    $next = "<a href='{$page->next($g)->url}'>next</a> ";

Should work, shouldn't it?

[tpr]

Have you tried adding any kind of "sort" to your query? ($g)

[Pete]

$g is an array of pages in your example that doesn't seem related to a particular page, so how does it know what next and prev are?

Next and prev usually relate to the page being viewed, so $page->next() and $page->prev() should be all you need.

[Mikel]

Yes, just added sort=title to the selector, but the method still returns NULL.

The funny thing is, the same code works on all other projects so far. Thats why I am wondering about dependencies ...

[Mikel]

$g is an array of pages in your example that doesn't seem related to a particular page, so how does it know what next and prev are?

Next and prev usually relate to the page being viewed, so $page->next() and $page->prev() should be all you need.

Hi, Pete,

I tried your code right after this:

$prev = ($page->prev->id) ? '<a href="'.$page->prev->url.'">'.$page->prev->title.'</a>' : '';
$next = ($page->next->id) ? '<a href="'.$page->next->url.'">'.$page->next->title.'</a>' : '';

Unfortunately neither is working...

[diogo]

Does it work if you do this instead?

$prev = "<a href='" . $page->prev($g)->url . "'>prev</a> ";

[Mikel]

Does it work if you do this instead?

$prev = "<a href='" . $page->prev($g)->url . "'>prev</a> ";

Unfortunately not :-(

But, as I stated before, the methods work fine in other projects, so I want to find the (to me) hidden dependency of these methods.

When I output the pageArray $g everything looks fine...

[diogo]

What do you get with: 

print_r($page->next($g))

?

[Soma]

It's all correct and works. So what is different to your other projects? Are pages published? Are they viewable? Is the page really in the PageArray, but when $page->next doesn't even work you seem to have a problem somewhere. No idea sorry.

[Mikel]

What do you get with: 

print_r($page->next($g))

?

I get this:

NullPage Object ( 
  [template:protected] => 
  [templatePrevious:Page:private] => 
  [parent:protected] => 
  [parentPrevious:Page:private] => 
  [namePrevious:Page:private] => 
  [statusPrevious:Page:private] => 
  [output:Page:private] => 
  [filesManager:Page:private] => 
  [fieldDataQueue:protected] => Array ( ) 
  [isNew:protected] => 1 
  [isLoaded:protected] => 1 
  [outputFormatting:protected] => 
  [instanceID:protected] => 0 
  [pageNum:protected] => 1 
  [config:protected] => 
  [quietMode:protected] => 
  [createdUser:protected] => 
  [modifiedUser:protected] => 
  [settings:protected] => Array ( 
     [id] => 0 
​ ​ ​   [name] => 
     [status] => 1 
     [numChildren] => 0 
     [sort] => -1 
     [sortfield] => sort 
     [modified_users_id] => 0 
     [created_users_id] => 0 
     [created] => 0 
     [modified] => 0 ) 
     [data:protected] => Array ( ) 
     [useFuel:protected] => 
     [className:Wire:private] => 
     [classNameOptions:Wire:private] => Array ( ) 
     [localHooks:protected] => Array ( ) 
     [trackChanges:Wire:private] => 0 
     [changes:Wire:private] => Array ( ) 
     [_notices:protected] => Array ( 
       [errors] => 
       [warnings] => 
       [messages] => 
    ) 
) 

[Mikel]

It's all correct and works. So what is different to your other projects? Are pages published? Are they viewable? Is the page really in the PageArray, but when $page->next doesn't even work you seem to have a problem somewhere. No idea sorry.

Hi, Soma,

thats what I'm trying to find out since a couple of hours...

pages are published - check

pages are viewable - check

page is in the pageArray because

print($g->each('<p>{title}</p>'));  

generates the correct output of all pages - check

[Mikel]

Hello everybody,

I finally made it up:

The project, still in development, is using Adrians nice module "Protected Mode". This module, if set to protected mode, seems to prevent the next() and prev() methods  from working correct. 

problem solved.

PS: After going through the "Protected Mode" module I wonder HOW this module can interfere with the next() and pre() methods... 

PPS: Now it gets really interesting: IT IS NOT "Protected Mode" module causing the next() & prev() methods to return NULL || nullPage object.

the dependency I detected meanwhile is if the current user is logged in or not:

anonymous user (aka "guest") --> everything works fine

logged in user --> methods return NULL

I will keep working on this one...

[adrian]

@Mikel and everyone else,

Sorry for the hassles - this has obviously been a pain for you and taken up other folk's time as well. 

I am trying to duplicate here, but can't and also can't figure out how it could be an issue - if you are logged in, the first line inside the module's init() returns before any it does anything else.

I'd love to be able to see a test installation where the problem is happening? Any chance you might be able to set up something on lightning.pw or elsewhere?

[diogo]

Adrian, read Mikel's correction above.

Mikel, next time you want to say something this important, do it in a new post so people know about the change

[Mikel]

@Mikel and everyone else,

Sorry for the hassles - this has obviously been a pain for you and taken up other folk's time as well. 

I am trying to duplicate here, but can't and also can't figure out how it could be an issue - if you are logged in, the first line inside the module's init() returns before any it does anything else.

I'd love to be able to see a test installation where the problem is happening? Any chance you might be able to set up something on lightning.pw or elsewhere?

Hi, Adrian,

sorry for this! Next time I will do this in a new post. 

mea maxima culpa! 

[mr-fan]

@Mikel

seems i've in the same trouble like you - did you get the problem solved?

[mr-fan]

Crosslink with solution in other threat.....just for connecting things right.

https://processwire.com/talk/topic/10731-how-to-debug-page-prev-page-next-no-output-given/#entry101066

regards mr-fan

[Mikel]

@Mikel

seems i've in the same trouble like you - did you get the problem solved?

No, we decided to drop everything relying on the prev() and next() methods until this gets fixed. If PW is able to return the sibling PageArray, it should to be able to traverse it, should't it? 

[Mikel]

After upgrading the ProcessWire installation to 2.7.2 the methods next() and prev() work like they should.