Image color based on value from a dataset

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1

Hi All, I am sure this has been addressed somewhere on the forum, but I didn’t find it…

I have a container with various controls in it. There is a dataset also associated with the container, with about 20 columns (just one row). I would like to use the value in one column (age) to change the color of an image in the container, but I don’t seem to be able to bind to a specific cell in the dataset through the property binding – property screen. I get an error "Property ‘dsTankData[0,15]’ not defined or not bindable for component ‘cnt801’. I browsed to Root Container.cnt801.dsTankData from within the property binding pop up, then added “[0,15]” after that to signify the first row, 15th column, just as one would do in a script module. No luck.

Next I tried to use an expression thusly: I created an integer dynamic property on the container, then tried to assign its value to the 0,15 of the dataset. I simply typed {Root Container.cnt801.dsTankData}[0,15]. The error this time was "The type of this expression (Object) is not assignment-compatible with the type of the property you are binding to (Integer).

I also looked at using dynamic styles (is that what they are called?) but had no luck with the same kind of binding…

Hmmm. What did I miss? TIA David

2

You were so close. Use the expression binding on the dynamic property, and cast it to an integer, like this:

toInt({Root Container.cnt801.dsTankData}[0,15])

You can then use another binding or the Styles feature to affect a color.

3

Thanks.

Now, to change the ‘tank color’ property of my tank, I tried:

if({Root Container.cnt801.intAge}>21,“0,124,0,255”,“0,0,0,0”)

but it didn’t like what it saw to be a string. Actually what I would like to do is if intAge is >25, make it black, between 17 and 25 make it yellow, and between 13 and 17 make it green.

I thought in the worst case a switch statement with all the possible values for intAge listed might work, but it seems messy, and there will inevitably be an intAge that isn’t caught… Thanks.

4

If you want to use an Expression binding you’ll have to use the Color
function.

if({Root Container.cnt801.intAge}>21,color(0,124,0,255), color(0,0,0,0))

You probably want to use styles - that will allow you to control all properties with flexible states. In your example you only have to create states for 0 (white), 13 (green), 17 (yellow), and 25 (black).

If the driving property values aren’t flexible enough, create an integer dynamic property bound to an expression that encapsulates your logic.

5

David,

It’s the casting that’s messing you up! “0,255,0,255” is not recognized as a color in the expression language so you have to cast it like this:if({Root Container.cnt801.intAge}>21,color(0,124,0,255),color(0,0,0,0))
Now if you like to read EVERY post on the forums (but I’ll just copy it here), there’s one about using a switch statement and binEnum() to get statements into your expression.

switch( binEnum({value}>25, {value}>17, {value}>13) 1,2,3, color(0,0,0,255), //black color(255,255,0,255), //yellow color(0,255,0,255), //green color(255,255,255,255)) //default
Or, like Nathan said as I was typing this, you could use styles.

6

Hi Robert: That was what I was thinking of. I tried the following:

switch( binEnum({Root Container.cnt801.intAge}>25, {Root Container.cnt801.intAge}>17, {Root Container.cnt801.intAge}>13) 1,2,3 color(0,0,0,255), //black color(255,255,0,255), //yellow color(0,255,0,255), //green color(255,255,255,255))

but got a syntax error on Token: ‘Integer const’ (line 5, char 1)
which is the line with 1,2,3 on it…

I tried the styles part, but where I hit a snag was that the hierarchy of objects is as follows: Root Container>>cnt801>>imgTank. I am trying to change the Tank Color property based on the value of intAge. However, intAge is on the cnt801 container, and is not available as a driving property for imgTank – for that my only choices were ‘Capacity’, ‘Data Quality’ and ‘Value’…

So, I am happy to use the switch statement above, but any advice as to why that syntax error… thing occurred?? thanks.

7

David,

You are missing a comma.

[code]switch(
binEnum({Root Container.cnt801.intAge}>25,
{Root Container.cnt801.intAge}>17,
{Root Container.cnt801.intAge}>13)

1,2,3, //<— here after the 3

color(0,0,0,255), //black
color(255,255,0,255), //yellow
color(0,255,0,255), //green
color(255,255,255,255))[/code]
If you want to use the intAge in your style, you can just make another dynamic property and bind it to the one on the container.

8

Thanks. Two missing commas, actually.

Here is the correct snippet:

switch( 
  binEnum({Root Container.cnt801.intAge}>25, 
          {Root Container.cnt801.intAge}>17, 
          {Root Container.cnt801.intAge}>13) 

1,2,3,  //<--- here after the 3 

color(0,0,0,255),           //black 
color(255,255,0,255),       //yellow 
color(0,255,0,255),         //green 
color(255,255,255,255))
9

Styles are mo’ betta - really!

10

Ack! Don’t use a switch expression to bind a color to a number. Even Styles is overkill for this. Just bind the color to the number using a property binding - there is a nice number-to-color translation map there for you!