Get value from blockly variable

[Julian]

Hey, 

I'm having a hard time getting the value from a blockly var.

Blockly.Blocks["variables_set_counter"] = {

init: function () {

this.appendValueInput("VALUE")

.setCheck(null)

.appendField("set")

.appendField(new Blockly.FieldVariable("zaehler"), "VAR")

.appendField("to");

this.setPreviousStatement(true, null);

this.setNextStatement(true, null);

this.setColour(330);

this.setTooltip("");

this.setHelpUrl("");

}

};

Blockly.JavaScript["variables_set_counter"] = function (block) {

var variable_var = Blockly.JavaScript.variableDB_.getName(

block.getFieldValue("VAR"),

Blockly.Variables.NAME_TYPE

);

var value_value = Blockly.JavaScript.valueToCode(

block,

"VALUE",

Blockly.JavaScript.ORDER_ASSIGNMENT

);

var code = variable_var + " = " + value_value + ";\n" + "setVar('" + block.id + "');\n";

return code;

};

Note: the "setVar(...)" is a helper for me to react when the js-interpreter is getting a var.

When I try to get the variables in my interpreter-method like this:

let allVars = Blockly.getMainWorkspace().getAllVariables();

I get the Variable-Model from blockly but no value:

0: Blockly.VariableModel

id_: "r@2;;rqJsQ*EY_An$({`"

name: "zaehler"

type: ""

workspace: Blockly.WorkspaceSvg { id: "V3E8I5+Z2Qx*h~:]`PeV", options: B…y.Options, RTL: false, horizontalLayout: false, toolboxPosition: 2, … }

__proto__: Object

length: 1

__proto__: Array(0)

The Variable-Model looks like this above. I get the name and the id but i need the value as well.

Thanks for any help.

dsadsadsad

[Beka Westberg]

Hello,

Would you mind clarifying a bit when/why you want to get the information about a variable? Is it for code generation? Is it for some sort of user-facing display? Some other reason? And where is the getAllVariables() function getting called?

I think we can probably find a way to grab this information, I just want to know a bit more about the situtation before I start recommending things : ). Once the problem is figured out I'm sure someone here can help you!

--Beka

[Julian]

Thanks for your fast response.

I need the value of a variable while stepping over the blockly-generated code with js-interpreter. In the example beneath the interpreter is stepping over moveforward();

var counter = 1;

setVar(block_id); // this is the helper I added to the code to handle when variables have to be set

when the interpreter is calling setVar(block_id) i get the block by id and get the variables by getAllVariables()... The problem is that the variable-models have no value field and i really don't know know where to get it.

Maybe also my way with this extra method in the blockly-generated code is no the best practice and you know other ways to handle variables and inputs in the blockly-generated code and js-interpreter?

Thanks for your help.

[Beka Westberg]

Hi again,

So I'm still a little fuzzy on what you're trying to do. It seems like you're trying to pass the value of the variable out of the JS-Interpreter, so then the document can do something with it? If this is the case, I think one way to do it is to set up your generator like so:

Blockly.JavaScript["variables_set_counter"] = function (block) {
  var variable_var = Blockly.JavaScript.variableDB_.getName(
      block.getFieldValue("VAR"), Blockly.Variables.NAME_TYPE);
  var value_value = Blockly.JavaScript.valueToCode(
      block, "VALUE", Blockly.JavaScript.ORDER_ASSIGNMENT);

  // The below line is changed to pass value_value instead of block.id.
  var code = variable_var + " = " + value_value + ";\n" + "setVar('" + value_value + "');\n";
  return code;
};

If this isn't what you're looking for please message back! Hope it helps,

Beka

[Julian]

Thanks a lot :)

I think to pass the value into the parameter of my helper-function getVar is a good idea :) and will work.

To clear your confusion about what I'm doing here: I want to implement a blockly-maze task where pupils have to count their steps in a maze and whenever they set or get a variable i want to visualize the values of the used variables in different drawers. The blockly-docu is not very clear here how to handle variables with the interpreter so I decided to use a helperfunction in the blockly-generated code and i remove it when i show the code to the pupils. 

Thanks again for your help and if know any other good practice handling variables with js-interpreter I would be very interested. I also would be happy to share ideas about exercise-concepts in blockly if you are interested.

Best regards,

Julian

[Beka Westberg]

Hi Julian,

 

whenever they set or get a variable i want to visualize the values of the used variables in different drawers

Wow that sounds like a really cool idea! I like the idea of being able to "inspect" the code while it's running, almost like a debug tool. I think seeing what the variables are doing in real time would really help with concepts like loops.

 I also would be happy to share ideas about exercise-concepts in blockly if you are interested.

I would love to hear! 

--Beka

[Julian]

Hey guys, 

thanks for the help here. I found out a much better solution in the end which includes the usage of js_interpreter.

I still use the helper-function ("setVar()") which is generated from blockly-block-code like this:

var code =

variable_var +

" = " +

value_value +

";\n" +

"setVar('" +

block.id +

"=" +

value_value +

"') ;\n";

return code;

When i initialize the js_interpreter i just place the scope of js_interpreter in the function call like this:

intp.setProperty(

scope,

"setVar",

intp.createNativeFunction(function (b) {

return intp.createPrimitive(dataObj.setVar(b.toString(), scope));

})

);

My helper-function called from interpreter looks like this:

setVar: function(raw_id, scope) {

// set uservar to value:

var var_value = scope.properties.zaehler.data;

var split_index = raw_id.lastIndexOf("=");

var b_id = raw_id.slice(0, split_index);

var value_str = raw_id.slice(split_index + 1, raw_id.length);

console.log(value_str);

this.counter += parseInt(value_str);

this.visQueue.push(["showConsoleVis", b_id, var_value]);

}

As you can see the interpreter value of the current interpreted line is in my scope of the helper-function and everyone is happy.

[Andrew n marshall]

Glad you found the js_interpreter solution. I was just about to suggest it. In addition to allowing stepping and storing intermediate variable values, it is also highly recommended for security reasons.

--
Andrew

--
You received this message because you are subscribed to the Google Groups "Blockly" group.
To unsubscribe from this group and stop receiving emails from it, send an email to blockly+u...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.