topic How to Write Conditional Change Expressions？ in Discussions

How to Write Conditional Change Expressions？

lehaofeng — Fri, 18 Aug 2023 04:32:22 GMT

//case1
x={"a01","b02","c003"};
dt << select where(:name=="a01"|:name=="b02"|:name=="c003");

//case2
x={"a01","b02","c003","e03"};
dt << select where(:name=="a01"|:name=="b02"|:name=="c003"|:name=="e03");

//case3
x={"a01"};
dt << select where(:name=="a01")

I have a question: as in the three cases of the code below, I now have a list x that changes, so the code for the selection condition also changes, how can I write a piece of code with an expression that takes care of all the x's that change.

Re: How to Write Conditional Change Expressions？

jthi — Fri, 18 Aug 2023 04:57:27 GMT

You could use Contains() instead of Or()

Names Default To Here(1);

x = {"a01", "b02", "c003"};

dt << select where(:name == "a01" | :name == "b02" | :name == "c003");
// to
dt << select where(Contains(x, :name));

Re: How to Write Conditional Change Expressions？

lehaofeng — Fri, 18 Aug 2023 05:06:24 GMT

Thank you, but the filter where in the tablebox only works like this.For example： tablebox << filter where(contains(x,colname), will report an error

Re: How to Write Conditional Change Expressions？

jthi — Fri, 18 Aug 2023 05:36:28 GMT

Few questions:

Where are you getting the x list?
What are you trying to filter?
What is triggering the action to filter?

Re: How to Write Conditional Change Expressions？

lehaofeng — Fri, 18 Aug 2023 05:42:02 GMT

1. x from a listbox
2. the value of a column in the tablebox
3. through the listbox selected elements, automatically change the tablebox table content, because the table there is a row with a buttonbox, so still want to achieve through filterwhere

Re: How to Write Conditional Change Expressions？

jthi — Fri, 18 Aug 2023 06:03:09 GMT

You might have to evaluate the variable

Names Default To Here(1);
New Window("Mountains",
	tb = Table Box(
		String Col Box("Mountain", {"K2", "Delphi", "Kilimanjaro", "Grand Teton"}),
		Number Col Box("Elevation (meters)", {8611, 681, 5895, 4199}),
		Plot Col Box("", {8611, 681, 5895, 4199})
	)
);
wait(1);
l = {"K2", "Delphi"};
Eval(EvalExpr(
	tb << Filter Where(Contains(Expr(l), Mountain));	
));

Re: How to Write Conditional Change Expressions？

lehaofeng — Fri, 18 Aug 2023 06:19:16 GMT

I can't believe that's the reason, learning, thanks.