Aggregate plug-in for TinyButStrong
by Skrol29, 2009-04-07
version 1.0.0

This plug-in can provide several types of aggregate calculations when a block is merged. It can do Sum, Min, Max, Average, Count, Accumulated values and Changed values.
Note: The current version cannot deal with header or footer sections, calculations are made over all records of the block, without rupture (this will perhaps be given by a next version).

PHP side:

Include the file 'tbs_plugin_aggregate.php'.
This plug-in requires TBS version 3.1 or higher.

Installation mode:
Automatic when included before the creation of the TBS variable.

If you include the plug-in file after the creation of the TBS variable, you should force the installation by using the following command:

Command syntax: (no command)

The last aggregate calculations are stored into a property of the TBS instance. This property is named Aggregate and its type is Array. Example:
$TBS = new clsTinyButStrong;
$sum = $TBS->Aggregate['price:sum'];

Template side:

1st step: Define calculations

Use parameter aggregate to declare all computed columns you'd like to use. The name of a computed column is columnX:operationX where columnX is the name of the original column used for the calculation, and operationX is the keyword of the operation (see the list below)
If you want to calculate the sum over column1, then add parameter "aggregate=column1:sum".
If you want to calculate several operations, then add "aggregate=column1:sum,column2:sum,..."

Note: Parameter aggregate is a block parameter, you have to place it in the same TBS tag as the one containing "block=...". Example:

Tip: If you have many computed columns and your tag become very long, you can use parameter comm to embed the TBS tag into a HTML comment. See parameter comm in the manual for more information.

2nd step: Display computed values

The computed columns are added in the dataset. You can display them like any other columns

Note: Some computed columns are available during the merge (like Acc and Chg), you can display their values by placing a TBS field inside the block. Some other columns are available only after the merge (like Sum, Min, Max,...), you can display their values by placing a TBS field only outside the block, otherwise a TBS error will raise. (see le list below).

Operation Description
Placement of the TBS tag
inside the block
outside the block
sum Sum of non null values  
avg Average of non null values  
min Min of non null values  
max Maximum of non null values  
count Number of records with a non null value  
acc Accumulated values
chg Values if changed, otherwise display ''


Product Price
[b.product;aggregate=price:sum] [b.price]
Total: [b.price:sum]

The field [b.price:sum] is on a computed column, this one must be placed outside the block (outise the <tr> here).

If you are merging several blocks with one MergeBlock(), then parameter aggregate will work correctly only with the first block's name. So you have to define all operations first the first block only. This should not be a problem since all data are available for all the merged blocks.
In this example, [b1.product;aggregate=price:sum] will work, but [b2.product;aggregate=price:sum] won't work.