• *expression_fold_constants Function
• *property_filter Function
• *substitute Function
• *summary_default_group_get Function
• a5_argumentsreplace Function
• a5_definearguments Function
• A5_EVAL_EXPRESSION Function
• a5_evalvalueexpr Function
• a5_expression_library Function
• a5_function_finder Function
• a5_gen_filter_component Function
• a5_get_expression_longnames Function
• a5_make_search_expn Function
• a5_parse_top_x_filter Function
• a5_prompt_special_filter Function
• a5_simpleargumentdefinition Function
• a5_unflatten_query Function
• a5_validate_xbasic_expression Function
• BETWEEN_CHAR Function
• BETWEEN_DATE Function
• BETWEEN_NUM Function
• BETWEEN_RECORD Function
• combine_filters Function
• eval_variables_valid Function
• EVALUATE_TEMPLATE Function
• EVALUATE_TEMPLATE_PRIVATE Function
• expression_demote_unique_keys Function
• expression_encode Function
• expression_reduce_filter Function
• filter_library_by_tags Function
• getfieldsinexpression Function
• IF Function
• SELECTLIST Function
• template_to_expression Function

A5_EVAL_EXPRESSION Function

Syntax

Arguments

expression

An Xbasic expression.

vars

*

Description

Used in code generated by the Script Genie. If expression starts with = then it evaluates it as an expression in the context of the current form.

Discussion

The A5_EVAL_EXPRESSION() function evaluates an expression in the context of the current form or browse window. Used extensively in the code generated by the Script Genie. In the Script Genie, in many of the places where you can specify a constant value, (such as the title of a dialog box), you can also specify an expression by simply preceding the value that you specify with an = sign.

Example

For example, "Show Selections" is a constant value, while =dlg_title signifies that the value should be obtained by evaluating the expression dlg_title. If dlg_title is a field on the current form, then a5_eval_expression("=dlg_title") returns the value in the dlg_title field. On the other hand a5_eval_expression("Alpha Anywhere") returns the constant value "Alpha Anywhere". The following example shows how to open an image (or any other file type, such as a PDF file) with its Windows associated application. The image's path and name are stored in an ordinary character field named " fileloc ". Put this code under the OnPush event of a button.

DIM filename as C
 filename = a5_eval_expression("=Fileloc") 
 if file.exists(filename) then 
 sys_open(filename) 
 else 
 ui_msg_box("Error Opening File", "File '" + filename + "' does not exist.", ui_stop_symbol) 
 end if

Limitations

Desktop applications only.

See Also

• Expression Evaluation Functions