New array from a foreach
7 posts by 4 authors in: Forums > CMS Builder
Last Post: August 13, 2010 (RSS)
By rjbathgate - August 11, 2010 - edited: August 11, 2010
Hello,
I have listviewer running on perPage. During the foreach stage, it runs a script to output a variable.
I want that variable available for the where of the listviewer - which is backwards/impossible.
So, need to do something like this:
load all records
foreach
{
run script and generate variable = xxxx
}
now load all records again but with variable xxx available
This is normally easy, but I need the use the SECOND set of records in the perPage.
So, I take from that I need do to this:
list all records
foreach
{
run script and generate variable = xxxx
add this record and new variable into array
}
now list this newly created array
foreach in this new array
{
}
perPage based on this new array
Dave in his expert wisdom has tackled a similar scenerio a few times for me before but I'm not sure if the above principle is right.
If it is, how do I create the new array and then call it for the subsequent foreach?
If it isn't the right way... any pointers?!
If none of this makes sense, sorry!
Cheers
I have listviewer running on perPage. During the foreach stage, it runs a script to output a variable.
I want that variable available for the where of the listviewer - which is backwards/impossible.
So, need to do something like this:
load all records
foreach
{
run script and generate variable = xxxx
}
now load all records again but with variable xxx available
This is normally easy, but I need the use the SECOND set of records in the perPage.
So, I take from that I need do to this:
list all records
foreach
{
run script and generate variable = xxxx
add this record and new variable into array
}
now list this newly created array
foreach in this new array
{
}
perPage based on this new array
Dave in his expert wisdom has tackled a similar scenerio a few times for me before but I'm not sure if the above principle is right.
If it is, how do I create the new array and then call it for the subsequent foreach?
If it isn't the right way... any pointers?!
If none of this makes sense, sorry!
Cheers
Re: [rjbathgate] New array from a foreach
By Perchpole - August 12, 2010
Hi, RJ -
This all sounds very familiar! I had a similar problem with a menu system...
In order to style the menu it was necessary to identify the first and last items in each drop-down. This should be easy enough - until you start filtering entries with if/{continue} arguments.
When this happens, first and last aren't always where you expect them to be!
The only thing you can do is pass each filtered menu item into another array with one foreach loop - and then display it with another foreach loop!
Does your head hurt yet?
:0)
Perchpole
This all sounds very familiar! I had a similar problem with a menu system...
In order to style the menu it was necessary to identify the first and last items in each drop-down. This should be easy enough - until you start filtering entries with if/{continue} arguments.
When this happens, first and last aren't always where you expect them to be!
The only thing you can do is pass each filtered menu item into another array with one foreach loop - and then display it with another foreach loop!
Does your head hurt yet?
:0)
Perchpole
Re: [rjbathgate] New array from a foreach
By Jason - August 12, 2010
Hi,
So you're going to run through your list of records once and create a new array, and then display the array you just created. Is that right?
If you could give me some more details on what would be in that second array, I can try to give you some examples on how that would work.
Thanks.
So you're going to run through your list of records once and create a new array, and then display the array you just created. Is that right?
If you could give me some more details on what would be in that second array, I can try to give you some examples on how that would work.
Thanks.
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Re: [Jason] New array from a foreach
Hi,
One (of a few) instances I need this is a follow up job to some of the custom work Ross/you are doing for me -- on the vehicle pricing!
When Ross has finished it will hopefully work like this:
All well and good.
I want to be able to do the following with $totalprice
a) allow the records to be sortable by price (high > low/low > high)
b) allow the search engine to have a max_ and min_ total price
For the above two, the array displayed needs to include the $totalprice as part of it... as far as I cna understand.
Using continue; within the foreach if the $totalPrice doesn't fit within max_ for example meses up Next/Previous links and also doesn't work with Sorting.
This is early in the morning for me, so the below might be stupid, but one thought:
In my head, making the new array of num and totalprice and then using that num to pull back the cmsb vehicle record seems logical.
And possibly possibly just by creating a new array and pushing records to it in each foreach? And then I'd just need to write a foreach based on that new array.
But is there a massive strain of calls to the database doing that?
And does that make no sense?
Cheers!
One (of a few) instances I need this is a follow up job to some of the custom work Ross/you are doing for me -- on the vehicle pricing!
When Ross has finished it will hopefully work like this:
list all vehicles, based on criteria of a standard search
foreach vehicle
{
Display vehicle info
Run a custom code (ross working on) to output variable $totalprice
Display $totalprice
}All well and good.
I want to be able to do the following with $totalprice
a) allow the records to be sortable by price (high > low/low > high)
b) allow the search engine to have a max_ and min_ total price
For the above two, the array displayed needs to include the $totalprice as part of it... as far as I cna understand.
Using continue; within the foreach if the $totalPrice doesn't fit within max_ for example meses up Next/Previous links and also doesn't work with Sorting.
This is early in the morning for me, so the below might be stupid, but one thought:
list all vehicles, based on criteria of a standard search
foreach vehicle
{
Run a custom code (ross working on) to output variable $totalprice
add into new array $newVehiclesArray the variables $totalprice and $vehiclenum
}
foreach in newVehiclesArray
{
look up vehicleRecord in CMS where num = $vehicleNum (allowing us to display all the standard CMSB data for this record)
display $totalprice
}In my head, making the new array of num and totalprice and then using that num to pull back the cmsb vehicle record seems logical.
And possibly possibly just by creating a new array and pushing records to it in each foreach? And then I'd just need to write a foreach based on that new array.
But is there a massive strain of calls to the database doing that?
And does that make no sense?
Cheers!
Re: [rjbathgate] New array from a foreach
By Chris - August 12, 2010
Hi rjbathgate,
That's the main concern with your approach, yes: on every search page, you'd need to load all the records from the database.
Depending on the complexity of the totalprice calculation, it may be possible to get MySQL to calculate it for you during the SELECT, allowing you to use it to paginate and sort.
Another option would be a custom plugin which automatically updates a totalprice field whenever a record in that section is saved.
I'd need to see the specifics on how totalprice is calculated to figure out what approaches would make sense.
I hope this helps! Please let me know if you have any questions.
P.S. Rather than pushing the $totalprice and $vehiclenum into your new array, it would probably be better to push the $totalprice and the entire $record into the array -- then you won't need to look anything up by num!
That's the main concern with your approach, yes: on every search page, you'd need to load all the records from the database.
Depending on the complexity of the totalprice calculation, it may be possible to get MySQL to calculate it for you during the SELECT, allowing you to use it to paginate and sort.
Another option would be a custom plugin which automatically updates a totalprice field whenever a record in that section is saved.
I'd need to see the specifics on how totalprice is calculated to figure out what approaches would make sense.
I hope this helps! Please let me know if you have any questions.
P.S. Rather than pushing the $totalprice and $vehiclenum into your new array, it would probably be better to push the $totalprice and the entire $record into the array -- then you won't need to look anything up by num!
All the best,
Chris
Chris
Re: [chris] New array from a foreach
Hey Chris,
Cheers for the reply.
You mention "on every search page, you'd need to load all the records from the database." --- I'd still be applying the normal search engine criteria so surely it's not different to running it normally?
I'd just be loading the given results, twice... ? And since it's perPage limited, it's only going to be say 20 results max = 40 = not too many...
I think.
I think the totalprice calculation is too complex during the SELECT - it involves relationships between 3 other tables...
And I think the updating totalprice field when a record is saved isn't applicable as it's for a constant quotation system - not wanting to add/save anything to the records as there will be potentially multiple quotes going on at one time.
So, if i take my option (if it's not too many database calls), do you have any sample code whcih lets me create the new array during the original foreach, and then run a new foreach based on this array?
Thanks!
Cheers for the reply.
You mention "on every search page, you'd need to load all the records from the database." --- I'd still be applying the normal search engine criteria so surely it's not different to running it normally?
I'd just be loading the given results, twice... ? And since it's perPage limited, it's only going to be say 20 results max = 40 = not too many...
I think.
I think the totalprice calculation is too complex during the SELECT - it involves relationships between 3 other tables...
And I think the updating totalprice field when a record is saved isn't applicable as it's for a constant quotation system - not wanting to add/save anything to the records as there will be potentially multiple quotes going on at one time.
So, if i take my option (if it's not too many database calls), do you have any sample code whcih lets me create the new array during the original foreach, and then run a new foreach based on this array?
Thanks!
Re: [rjbathgate] New array from a foreach
By Chris - August 13, 2010
Hi rjbathgate,
You're right in that other search criteria, if present, will trim down the number of records you need to get, but pagination needs to be redone.
Consider this: if you wanted to display the second page of results of people with a phone number which is a prime number, which pages of the phone book would you need to look at?
Since one of your criteria is dependent on examining the result set, the simplest solution is to return the entire result set and then paginate in PHP.
SQL tends to be pretty good at this kind of thing. ;)
Sure:
Does that help? Please let me know if you have any questions.
You're right in that other search criteria, if present, will trim down the number of records you need to get, but pagination needs to be redone.
Consider this: if you wanted to display the second page of results of people with a phone number which is a prime number, which pages of the phone book would you need to look at?
Since one of your criteria is dependent on examining the result set, the simplest solution is to return the entire result set and then paginate in PHP.
I think the totalprice calculation is too complex during the SELECT - it involves relationships between 3 other tables...
SQL tends to be pretty good at this kind of thing. ;)
So, if i take my option (if it's not too many database calls), do you have any sample code whcih lets me create the new array during the original foreach, and then run a new foreach based on this array?
Sure:
<?php
list($phone_bookRecords, $phone_bookMetaData) = getRecords(array(
'tableName' => 'phone_book',
));
// build a new array from some of the records
$newArray = array();
foreach ($phone_bookRecords as $record) {
$isPrime = is_prime($record['phone_number']); // example: function not provided
if ($isPrime) {
$newElement = array($record, $isPrime); // example: storing extra information with the record
array_push($newArray, $newElement);
}
}
// crop out the requested page of results
$perPage = 10;
$pageNum = @$_REQUEST['page'];
if (!$pageNum) { $pageNum = 1; }
$newArrayCurrentPage = array_slice($newArray, ($pageNum - 1) * $perPage, $perPage);
?>
<ul>
<?php foreach ($newArrayCurrentPage as $row): ?>
<li>
<?php list($record, $isPrime) = $row; ?>
<?php echo $record['name'] ?>
<?php echo $record['phone_number'] ?>
<?php echo $isPrime ?>
</li>
<?php endforeach ?>
</ul>Does that help? Please let me know if you have any questions.
All the best,
Chris
Chris