Changes between Initial Version and Version 1 of HowTos/HowToUseGenericDatabaseMessages/UsingmodelglueGenericRead

Timestamp:

04/15/09 19:43:28 (17 years ago)

Author:

trac (IP: 127.0.0.1)

Comment:

--

HowTos/HowToUseGenericDatabaseMessages/UsingmodelglueGenericRead

@@ +1 @@
+= Using modelglue.!GenericRead =
+
+When this message is broadcast, the !DataController will attempt to read a specific record from a given table.
+
+This message is configured by using the following <argument> tags:
+
+  1. Object (Required) - The name of the table from which to read.
+  1. !RecordName (Optional) - The name of the viewstate value to set the resultant record into. Defaults to Object & "Record".
+  1. Criteria (Optional) - A list of viewstate values to use as filters. Any value listed whose name matches a column in the target table will be used as a filter in the query's WHERE clause. This will most often be set to a list of the table's primary keys. If left empty, a new record will be created.
+
+== Examples ==
+
+=== A Basic Generic Read ===
+
+To perform a basic read on a Contact table, the following <message> tag could be added to an <event-handler>:
+
+{{{
+<message name="modelglue.GenericRead">
+
+<argument name="object" value="Contact" />
+
+</message>
+}}}
+
+A View could then <cfdump> the record by performing the following code:
+
+{{{
+<cfdump var="#viewstate.getValue("ContactRecord") />
+}}}
+
+Note: Because no criteria were specified, this would return a new, empty record.
+
+=== Customizing the Viewstate value name ===
+
+To perform a basic read on a Contact table and set it into a specific value in the Viewstate, the following <message> tag could be added to an <event-handler>:
+
+{{{
+<message name="modelglue.GenericRead">
+
+<argument name="object" value="Contact" />
+
+<argument name="recordName" value="myContact" />
+
+</message>
+}}}
+
+A View could then <cfdump> the record by performing the following code:
+
+{{{
+<cfdump var="#viewstate.getValue("myContact") />
+}}}
+
+Note: Because no criteria were specified, this would return a new, empty record.
+
+=== Reading a Specific Record ===
+
+To perform a basic read of a Contact record that would filter on the viewstate's current !ContactId value, the following <message> tag could be added to an <event-handler>:
+
+{{{
+<message name="modelglue.GenericRead">
+
+<argument name="object" value="Contact" />
+
+<argument name="criteria" value="ContactId" />
+
+</message>
+}}}
+
+Assuming an event-handler name of "contact.read", visiting the event handler with the following URL would result in reading a contact with a !ContactId value of 42.
+
+index.cfm?event=contact.read&contactId=42