Read (Screen function): Difference between revisions

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This callable function does the actual write of the screen to the "terminal," and it invokes a Model 204 wait while the user responds to the displayed screen. It then reads from the terminal the subsequent user response and updates the values of any modified ScreenField objects.
{{Template:Screen:Read subtitle}}
The <var>Read</var> [[Notation_conventions_for_methods#Callable_methods|callable]] function does the actual write of the screen to the "terminal," and it invokes a <var class="product">Model 204</var> wait while the user responds to the displayed screen. It then reads from the terminal the subsequent user response and updates the values of any modified <var>[[Screen classes|ScreenField]]</var> objects.


  [%key =] %screen:Read
==Syntax==
{{Template:Screen:Read syntax}}
===Syntax terms===
<table class="syntaxTable">
<tr><th>%key</th>
<td>A declared <var>[[Screen classes#ActionKey_enumeration|ActionKey enumeration]]</var> set to the identifier of the key that activated the reading of the screen.  Valid values (case unimportant) are <var>Enter</var> and <var>pf1</var>, <var>pf2</var>, and so on through <var>pf24</var>. </td></tr>


; <font size='3'>Read syntax</font>
<tr><th>screen</th>
<td>A reference to an instance of a <var>Screen</var> object.</td></tr>
</table>


; %key
==Usage notes==
: A declared actionKey enumeration set to the identifier of the key that activated the reading of the screen. Valid values (case unimportant) are Enter and pf1, pf2, and so on through pf24.
<ul><li>The <var>[[Modified_(ScreenField_property)|Modified]]</var> property is reset for all non-protected <var>ScreenFields</var> after the <var>Read</var> method is invoked.  If a particular <var>ScreenField</var> value has been modified by the user, the <var>Modified</var> property for that field is set to <code>True</code>. Otherwise, the <var>Modified</var> property is set to <code>False</code>.
</ul>


; %screen
==Examples==
: A reference to an instance of a Screen object.
For an example using the <var>Read</var> method, see [[Screen object sample code|"Screen object sample code"]].


; <font size='3'>Usage Notes</font>
==See also==
 
{{Template:Screen:Read footer}}
The Modified property is reset for all non-protected
ScreenFields after the Read method is invoked. If a particular ScreenField value
has been modified by the user, the Modified property for that field is set to True.
Otherwise, the Modified property is set to False.
 
For an example using the Read method, see [[Screen Object Sample Code]].

Latest revision as of 22:59, 16 November 2012

Write screen to display and return response (Screen class)

The Read callable function does the actual write of the screen to the "terminal," and it invokes a Model 204 wait while the user responds to the displayed screen. It then reads from the terminal the subsequent user response and updates the values of any modified ScreenField objects.

Syntax

[%key =] screen:Read Throws ScreenReadError

Syntax terms

%key A declared ActionKey enumeration set to the identifier of the key that activated the reading of the screen. Valid values (case unimportant) are Enter and pf1, pf2, and so on through pf24.
screen A reference to an instance of a Screen object.

Usage notes

  • The Modified property is reset for all non-protected ScreenFields after the Read method is invoked. If a particular ScreenField value has been modified by the user, the Modified property for that field is set to True. Otherwise, the Modified property is set to False.

Examples

For an example using the Read method, see "Screen object sample code".

See also