Aggregate plug-in for TinyButStrong
by Skrol29, 2006-07-25
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:

Requirements:
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:
$TBS->PlugIn(TBS_INSTALL,TBS_AGGREGATE);



Command syntax: (no command)

Miscellaneous:
The last aggregate calculations are stored into a property of the TBS instance. This property is named Aggregate and its type is Array. Example:
include_once('tbs_plugin_aggregate.php');
$TBS = new clsTinyButStrong;
$TBS->MergeBlock('b',$data);
$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)
Example:
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:
[b.product;block=tr;aggregate=sum:price]

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
Example:
[column1:sum;frm='0,000.00']

Note: Some 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 ''
•
•

Example:

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).