Skip to main content

Notice: this Wiki will be going read only early in 2024 and edits will no longer be possible. Please see: https://gitlab.eclipse.org/eclipsefdn/helpdesk/-/wikis/Wiki-shutdown-plan for the plan.

Jump to: navigation, search

Difference between revisions of "Scout/Concepts/LookupCall"

(Members)
(Replaced content with "{{ScoutPage|cat=Shared}} Moved to new Scout documentation at http://eclipsescout.github.io/6.0/technical-guide.html#lookup-call")
Line 1: Line 1:
 
{{ScoutPage|cat=Shared}}
 
{{ScoutPage|cat=Shared}}
  
Lookup calls are mainly used by {{ScoutLink|Concepts|SmartField|SmartFields}} and {{ScoutLink|Concepts|SmartColumn|SmartColumns}} to look up single or multiple {{ScoutLink|Concepts|LookupRow|LookupRows}}.
+
Moved to new Scout documentation at http://eclipsescout.github.io/6.0/technical-guide.html#lookup-call
 
+
* Class: {{ScoutJavadoc|LookupCall|C}}
+
 
+
== Description ==
+
 
+
The Lookup call mechanism is used to lookup up a set of key-text pairs. Whereas the ''key'' can be of any Java type the ''text'' must be of the type String. Each entry in this set is called LookupRow. In addition to the ''key'' and the ''text'' a LookupRow can also define and icon, font, colors and a tooltiptext.
+
 
+
This schema explains the role of a LookupCall in a SmartField:
+
 
+
[[Image:Schema LookupCall.png]]
+
 
+
=== Input ===
+
Lookup calls provide different method to compute the set of {{ScoutLink|Concepts|LookupRow|LookupRows}} :
+
 
+
* <code>getDataByKey()</code>: Retrieves a single lookup row for a specific key value. Used by SmartFields and SmatColumns to get the display text for a given key value.
+
* <code>getDataByText()</code>: Retrieve multiple lookup rows which match a certain String. Used by SmartFields when the user starts to enter some text in the field.
+
* <code>getDataByAll()</code>: Retrieves all available lookup rows. Used by SmartFields when the user clicks on the browse icon.
+
* <code>getDataByRec()</code>: This can only be used for hierarchical lookup calls. It retrieves all available sub-tree lookup rows for a given parent.
+
 
+
=== Members ===
+
The Lookup call contains attributes (accessible with getter and setter) that can be used to compute the list of lookups rows. Out of the box you have:
+
 
+
* key: contains the key value when the lookup is queried by key.
+
* text: contains the text input in case of a text lookup (typically this is the text entered by the user smart field).
+
* all: contains the browse hint in case of a lookup by all (typically when a user click on the button to see all proposal in a smart field).
+
* rec: contains the key of the parent entry, in when the children of a node are loaded.
+
* master: contains the value of the master field (if a master field is associated to the field using the lookup call).
+
 
+
It is possible to add you own additional attributes, for example validityFrom, validityTo as date parameter. Just add them as field with getter and setter:
+
 
+
<source lang="java">
+
public class LanguageLookupCall extends LookupCall {
+
  //other stuff like serialVersionUID, Lookup Service definition...
+
 
+
  private Date m_validityFrom;
+
  private Date m_validityTo;
+
 
+
  @Override
+
  protected Class<? extends ILookupService> getConfiguredService() {
+
    return ILanguageLookupService.class;
+
  }
+
 
+
  public Date getValidityFrom() {
+
    return m_validityFrom;
+
  }
+
 
+
  public void setValidityFrom(Date validityFrom) {
+
    this.m_validityFrom = validityFrom;
+
  }
+
 
+
  public Date getValidityTo() {
+
    return m_validityTo;
+
  }
+
 
+
  public void setValidityTo(Date validityTo) {
+
    this.m_validityTo = validityTo;
+
  }
+
}
+
</source>
+
 
+
In this case, you might want to set your properties bevor the lookupcall query is sent. This can be done with the {{ScoutEvent|PrepareLookup}} event of the SmartField or the ListBox:
+
 
+
<source lang="java">
+
@Override
+
protected void execPrepareLookup(LookupCall call) throws ProcessingException {
+
  LanguageLookupCall c = (LanguageLookupCall) call;
+
  c.setValidityFrom(DateUtility.parse("2012-02-26", "yyyy-mm-dd"));
+
  c.setValidityTo(DateUtility.parse("2013-02-27", "yyyy-mm-dd"));
+
}
+
</source>
+
 
+
If you follow this pattern, you will consume the values in the server, by casting the call:
+
 
+
<source lang="java">
+
@Override
+
public LookupRow[] getDataByAll(LookupCall call) throws ProcessingException {
+
  LanguageLookupCall c = (LanguageLookupCall) call;
+
  Date validityFrom = c.getValidityFrom();
+
  Date validityTo = c.getValidityTo();
+
 
+
  //compute result: corresponding lookup rows (depending on validityFrom and validityTo).
+
  return result;
+
}
+
</source>
+
 
+
== Type of lookup calls ==
+
===With a Lookup Service===
+
Delegation to the {{ScoutLink|Concepts|Lookup Service|Lookup Service}} on server side.
+
 
+
They are not necessarily restricted to a fix number of records. Instead they should be favoured if the set of records is rather large.
+
 
+
===Directy===
+
Principe of the {{ScoutLink|Concepts|LocalLookupCall|Local Lookup Calls}}
+
{{note|TODO|Explain and mention the execCreateLookupRows method}}
+
 
+
An example of this approach is when a SmartField or a SmartColumn is configured to be use with a {{ScoutLink|Concepts|CodeType|CodeType}}. A {{ScoutJavadoc|CodeLookupCall|C}} is instantiated for the CodeType. It creates the LookupRows corresponding to the {{ScoutLink|Concepts|Code|codes}}  in the CodeType.
+
 
+
== Overview ==
+
[[Image:LookupCall.png]]
+
 
+
== Properties ==
+
''Defined with {{ScoutLink|Concepts|GetConfigured Methods|getConfiguredXxxxxx()}} methods''.
+
 
+
* {{ScoutProp|Service}}: Defines which service is used to retrieve lookup rows
+
* {{ScoutProp|MasterRequired}}: Defines whether a master value must be set in order to query for multiple lookup rows
+
 
+
== Code example ==
+
=== Using a LookupCall in a SmartField ===
+
<source lang="java">
+
public class ColorSmartField extends AbstractSmartField<String> {
+
  // other configuration of properties.
+
  @Override
+
  protected Class<? extends LookupCall<?>> getConfiguredLookupCall(){
+
    return ColorLookupCall.class;
+
  }
+
}
+
</source>
+
 
+
=== Accessing a LookupRow directly ===
+
It is possible to access a LookupRow direclty. In this example the input is a key (<code>thisKey</code>) and the method <code>getDataByKey()</code> is used.
+
Before accessing the text, we ensure that a LookupRow has been retrived.
+
 
+
<source lang="java">
+
//Execute the LookupCall (using DataByKey)
+
LookupCall call = new MyLookupCall();
+
call.setKey(thisKey);
+
LookupRow[] rows=call.getDataByKey();
+
   
+
//Get the text (with a null check)
+
String text = null;
+
if(rows != null && rows.length > 0) {
+
  text = rows[0].getText();
+
}
+
</source>
+
 
+
== See Also ==
+
* {{ScoutLink|Concepts|LookupRow|Lookup Row}}
+
* {{ScoutLink|Concepts|Lookup Service|Lookup Service}}
+
* {{ScoutLink|Concepts|LocalLookupCall|Local Lookup Calls}}
+
* {{ScoutLink|Concepts|Shared Plug-In|Shared Plug-In}}
+

Revision as of 11:04, 29 June 2016

The Scout documentation has been moved to https://eclipsescout.github.io/.

Moved to new Scout documentation at http://eclipsescout.github.io/6.0/technical-guide.html#lookup-call

Back to the top