Read (Screen function): Difference between revisions
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{{Template:Screen:Read subtitle}} | {{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. | |||
==Syntax== | ==Syntax== | ||
{{Template:Screen:Read syntax}} | {{Template:Screen:Read syntax}} | ||
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<table class="syntaxTable"> | <table class="syntaxTable"> | ||
<tr><th>%key</th> | <tr><th>%key</th> | ||
<td>A declared | <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> | ||
<tr><th> | |||
<td>A reference to an instance of a Screen object.</td></tr> | <tr><th>screen</th> | ||
<td>A reference to an instance of a <var>Screen</var> object.</td></tr> | |||
</table> | </table> | ||
==Usage notes== | ==Usage notes== | ||
<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> | |||
==Examples== | |||
For an example using the <var>Read</var> method, see [[Screen object sample code|"Screen object sample code"]]. | |||
==See also== | ==See also== | ||
{{Template:Screen:Read footer}} | {{Template:Screen:Read footer}} | ||
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 toFalse.
Examples
For an example using the Read method, see "Screen object sample code".