How to find flow item from string?

[shanice_c]

[ FlexSim 22.0.0 ]

Hello, I have an external database, and I would change flow item also get some information from database. There problem in find flow item. I have printed out the "/Product1", next step is to assign token.producttake by using "model().find()".

[joerg_vogel_HsH · Accepted solution]

You don’t need the slash. The product need a unique name to find it successfully.
Alternatively you can store an item by its number inside FlexSim.
Command is tonum( a thing). A thing can be a node. Later you can convert this number back to a node by command tonode( from thing number).

[jason_lightfootVL7B4]

It's better to push items to a list and then pull from that list using a WHERE clause or by partition than using find each time. That way you get a direct pointer (or array of pointers) to the item(s).

[shanice_c]

@Joerg Vogel Thank you for the response. I have tried not putting a slash, but still return no path. I found "?" could return the node reference. "token.producttake" could be assigned.

[joerg_vogel_HsH]

@shanice.c , any search by method find will only work successfully, if you have a unique name for each item or object your are looking for! Typically products have equal names like “Product”. Such a Name won’t work, because it isn’t unique. I think you should go with Jason’s suggestion.

[joerg_vogel_HsH]

Structal remark. A query result is always a table and not an array. This means you have to check a table cell by its row and column value. So far you check or assign values only by a column name for a row value.

[shanice_c]

@Joerg Vogel Thank you for your reminds, I might encounter these problems soon.

I could understand 2 things you said. My organization is trying to control Flexsim object by only give agv information it needs(such as fromstation, tostation, whatproduct), and is not going to use process flow to handle any logic in flexsim.

We try to write our logic using external codes, and put information into database. Objects in flexsim are not doing any logic, only query a table recording tasks to check if any tasks to do. If no, just stay there.

[joerg_vogel_HsH]

Then you have a unique key identifying each object in your data base. Now you need a reference to this object in FlexSim. Each Objects reference can be converted to an number by command tonum(thing). This is an absolute unique reference inside FlexSim.

A name can only be resolved to a reference, if each object has got an unique name in the scope of your model.

A relative path description by a string won't work in your case sufficiently, because you would have to be absolutely sure your object is still there when you evaluate the path again.

Because you control FlexSim externally, you have to store in your data base a key which stores the converted objects reference as a number. Or you will translate your own key from an external database inside FlexSim by a List. A List is not a Process Flow structure. It is a structure of the command environment of FlexSim.

[shanice_c]

@Joerg Vogel May I ask how to use tonode()? I follow the example below to use tonum().

and the result on token are same, both "1558663349728"?

but when I look for "uniqueid" from tree, they are 94, 95.

[joerg_vogel_HsH]

unique_item_id.fsm

Item must be present in model. Item must be at different location.

Former versions of Flexsim have got an option to keep once created items in memory.

[shanice_c]

@Joerg Vogel Sorry, I couldn't download attached model.

[joerg_vogel_HsH]

@shanice.c, file updated!

[shanice_c]

@Joerg Vogel Thanks for the provided method. Since we create Source data for simulation, our products have unique name. I've tried the tonum() to get unique id and used tonode() method to returned this double type data to pointer. I would try to use these methods in the future.

unique-item-id_s.fsm