Form Storage Mechanisms

A storage mechanism is defined by subclass I2CE_FormStorage_Mechanism which provides the methods to read, and possibly write, the data for any form with the given mechanism. If the data is stored in a database, it can sub-class I2CE_FormStorage_DB and provide read access to the data as a form by only defining one method, getRequiredFieldsQuery(). To make a storage mechanism writable, you only need to write a method which defines how to store a data field.

Once a storage mechanism is written, the data for that form can be queried via searches with limits.

The currently (or soon-to-be) available storage mechanisms are:

• entry: A vertical database storage mechanism which keeps a history of when and by who individual fields (data elements) were changed. This is the default storage mechanism, and the storage mechanism that was used in version prior to 3.2.
• flat: A horizontal database storage mechanism, where a row of a table corresponds to an instance of a form. The columns, or any SQL function, of the table are used to define the fields.
• multi_flat: A horizontal database storage mechanism similar to the flat storage mechanism but combining several identically structured tables. It is primarily intended for data collation.
• magicdata: A locale aware storage mechanism primarily intended for centrally maintained lists of data.
• CSV: A storage mechanism to read data from a CSV file
• Eval: A storage mechanism to populate and get records based on php function calls
• SDMX-HD: A storage mechanism to populate and get records based on SDMX-HD code lists.
• SDMX Cross Sectional: A storage mechanism to populate and get records based on SDMX Cross Sectional Data.

Storage mechanisms are easy to write, and some other possibilities for storage mechanisms which could be added are for:

• Data stored in XML files.
• Data stored in a CSV file.

Much base functionality is provided in I2CE_FormStorage_Mechanism, although these methods may be overwritten to improve speed.

Aggregating Storage Mechansims

You may be in a situation in which you need to aggregate from several different instances of iHRIS Manage (or Qualify). You can mark a specific a storage mechanism, $storage_mechanism, as being aggregating by setting:

/modules/forms/storage_options/$storage_mechanism/componentized

to 1. Then each form $form that uses that storage mechanism, will be componetized.

At the moment, only the Multi-Flat storage mechanism is an aggregating storage mechanism.

Once the form-storage module is enabled, an instance of I2CE_Form has the method isComponentized() to check if a form is componentized. You can also check via I2CE_FormStorage::isComponentized($form)