> The Delete From Array function has some interesting polymorphic behavior... > it changes the type of one of its output terminals based on *whether* an > input terminal is wired (as opposed to what type is wired to the input > terminal). In particular, if length is unwired, a scalar is output. If > length is wired, an array is output. I would *love* do duplicate this > exact behavior for a Read Row(s) From File function. Anyone know if this > is possible? >
It is possible if the object is built into LV, but otherwise, you have to deal with looking at the value at runtime. It is possible to use nonsense defaults to determine if someone probably wired to an input, but you can't know for certain at the moment. Of course the other thing you can't do yet is build a growable node. For the best approximation of a growable node, you might consider putting a merge VI into the palettes. Build your VI to take an array, then make the palette drop your VI and some growable nodes prewired to it. It is pretty easy for the nodes to be grown or use all the features of the built-in, because it is the built-in. To make a merge VI, you make another VI, like a template with panel and diagram objects you want dropped. Add it to the palettes, and make it a merve VI. When dropped, it isn't a subVI call, but a copy paste of panel and diagram to where the user drops the palette object. Hopefully in a few releases, you guys can write all the nodes yourself and we can just go on vacation of something. Greg McKaskle
