Read (Screen function): Difference between revisions

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{{Template:Screen:Read subtitle}}
{{Template:Screen:Read subtitle}}
The <var>Read</var> <var>[[Notation_conventions_for_methods#Callable_methods|callable]]</var> 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>ScreenField</var> objects.
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==
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<table class="syntaxTable">
<table class="syntaxTable">
<tr><th>%key</th>
<tr><th>%key</th>
<td>A declared <var>[[Screen classes#ActionKey_enumeration|ActionKey]]</var> enumeration 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>
<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>screen</th>
<tr><th>screen</th>
<td>A reference to an instance of a <var>Screen</var> object.</td></tr>
<td>A reference to an instance of a <var>Screen</var> object.</td></tr>

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