selector children of children

[bwakad]

I have this code which I need to rewrite to retrieve a list of children pages from the parent under location.

location

- parent01

- - child

- - child

- parent02

- - child

- - child

foreach($pages->get("/location/")->children() as $municipal) {

I need to collect the childs. Is there something for this? Because I tried siblings() but that did no good.

Or do I need to first make a foreach on the parent, and inside foreach for the children? - if so is that good practise?

[Soma]

Depends what you want to do. Seems not like it's not something really used or needed, collecting id's of children's children for whatever reason that is.

Since we have an hierarchical structure and the API children parent, siblings is build for traversing, it may won't scale well (speaking of possibly thousands of pages) iterating with foreach and "collecting" ids. Always it's like this: for having a couple pages it may ok but won't scale infinitely. So it all depends largely on the structure you have and what templates they have. Taking all this into consideration will lead to new possibilities with API.

Usually of how I would have this is that the child have their own template so you could use a $locationParent->find("template=subchild"), which would scale more but still maybe an issue if you go for very large sets of pages.

But if it's only for small set of pages it may ok to just foreach all children and foreach each children of the children.

So having to "collect id's" always rings a red alarm: "For what, and how many?". 

[bwakad]

In total there are 400 pages as childrens. I use this as list select on a search form to search by municipal.

Meanwhile I was looking further in it and also noticed I can use the following code, but it will only give me the list of children under the first parent.

foreach($pages->get("children=/location/")->children() as $municipal) {

Perhaps if it is to heavy - which I think it is - the municipal is a field, so I better use this next code, change it a little to search in fields. That way it possibly does not need to go through all entries:

// if there are keywords, look in the title and body fields for the words
if($input->get->keywords) {
    $value = $sanitizer->selectorValue($input->get->keywords);
    $selector .= "title|body%=$value, ";
    $summary["keywords"] = $sanitizer->entities($value);
    $input->whitelist('keywords', $value);
}

[Soma]

You can't do 

children->children() cause children is a PageArray and not a single page.

always page->children()

Not sure what $pages->get("children=/location/")->children() is supposed to do?

So you want to build a <select> dropdown on a front-end form with all 400 as options?

400 is already a lot but would be no problem foreach the children, even nested if needed. It's where it start to get slow and you notice it may take 1-2 seconds to generate, but the searching and loading with PW isn't the problem (at least with 400), it's rendering the list. So in this case rendering 400 options for a select it would be wise to output the resulting markup and caching it using MarkupCache. That allows you to cache certain parts only of a page for a certain time. That would speed up not "loading" the list everytime. After all you don't have a choice than to foreach all the pages at the end, no? 

Please always be more/very specific to what you need to achieve and we can help more focused instead of trying to find out first what you're doing before a valueable explanation can be done. That can be very frustrating and lead to nobody helping you anymore. Collecting id's is something different thatn building a select.

I'll go focus on more important things now.

[bwakad]

Well, thanks for the effort anyway.

ps. I thought I was clear on what I wanted to do - from the topic title and description in the first post - but maybe i'm thinking simple - and others think php

[Soma]

You're right, I'm just oversaturating a little. Post title doesn't say anything. Collecting children does a little more, but we do that all the time (I got two)

Well there's sometimes a lot more than just how to, it's the what and where and why that may make a difference.

[Soma]

So to respond to your first post again:

I need to collect the childs. Is there something for this? Because I tried siblings() but that did no good.

No there's not, but yes there is.

Or do I need to first make a foreach on the parent, and inside foreach for the children? - if so is that good practise?"

Yes. Yes.

[Soma]

And last some code when children would have their own template:

$allChildren = $pages->get("/locations/")->find("template=child_tpl");

or even checking for parent template

$allChildren = $pages->get("/locations/")->find("parent.template=parent_tpl");

or

$allChild = new PageArray();
foreach($pages->get("/locations/")->children() as $parent) {
   foreach($parent->children() as $child) $allChildren->add($child);
}

and there's even more variations depending on who writes it.

[bwakad]

ok, I did not blame you Thinking what you said about speed an all, I was using the below code and looked in the API selectors.

In my search form:

the search form has

    <p>
    <label for='search_keywords'>Keywords</label>
    <input type='text' name='keywords' id='search_keywords' value='<?php
        if($input->whitelist->keywords) echo $sanitizer->entities($input->whitelist->keywords); ?>' />
    </p>

then it's send to the search.php where this part give me an error:

if($input->get->keywords) {
    $value = $sanitizer->selectorValue($input->get->keywords);
    $selector .= "title|body|municipal%=$value, ";
    $summary["keywords"] = $sanitizer->entities($value);
    $input->whitelist('keywords', $value);
}

I understood that it searches all fields for the value. If I use:

$selector .= "title|body%=$value, ";

everything fine, no error, but no search on municipal either.

[diogo]

Actually, this works:

$pages->find("parent={$pages->get('/location/')->children()}");

[Soma]

Actually, this works well:

$pages->find("parent={$pages->get('/location/')->children()}");

That's also nice solution and something that usually works well for smaller amounts, just doesn't scale very good and high. 

It just takes a lot more power and memory in my tests back then with large sets of pages (+10'000), for larger than 10'000 I couldn't even execute it on without getting out of memory , while the a direct ("parent.template=parent_tpl") takes almost no time compared. 

[bwakad]

Well, I like to thank you all for thinking with me, but I have to say Soma was right. 400+ in a list on front end is not to good! But hey, at least I learned something...

I will go for the sidebar and retrieve items from current page if any, so when I have a view of province, I get a list of cities.

[diogo]

but I have to say Soma was right. 400+ in a list on front end is not to good!

You managed to confuse me with this. 400 in a list is not too much because you can always paginate it, so I had to look for the place where Soma had said that, and what he really says is that 400 in a dropdown is too much. Maybe I'm just being picky, but someone might read this and start avoiding having long list on their sites.

[Soma]

Hm, I've never said 400 is too much, just that it will take some time to load and you could use markup cache Ryan does the same I guess for the modules.processwire.com dropdown with all 250 modules (actually maybe just ProCache anyway)

[bwakad]

Sorry for the confusion ... to tell you the truth, since I started this topic, and solutions where diverse, I really had to think which answer I had to marked as Solved.

I was talking about a drop down list - 400+ should not be to much problem server side, but maybe it's also not very usefull for client side.

Thinking client side, I prefer having a dropdown (if applicable) and when using a tab (keyboard) you see the whole list, so I can use my up/down keys or alphabet key to choose... but that's just me. That's why I had to go with soma answer.

I'm learning from you all !

[diogo]

Hm, I've never said 400 is too much

Soma, that's what I'm saying. You never said it