Type Conversion

There are multiple instances where a data needs to be converted into another type due to some properties only allowing specific data types. This can range from converting strings to numbers and vice-versa.

String to Number ​

The following code will create a label that will contain a string data at which will get turned into number.

"label": {
    "type": "label",
    "text": "#text",
    "property_bag": {
        "#str": "10",
        // You don't need to necessarily turn this into a binding
        // property but it alleviate problems later on the line.
        "#float": 1.0
    },
    "bindings": [
        {
            "binding_type": "view",
            "source_property_name": "(#str * 1)",
            "target_property_name": "#integer"
        },
        {
            "binding_type": "view",
            "source_property_name": "(#str * #float)",
            "target_property_name": "#float"
        },
        {
            "binding_type": "view",
            "source_property_name": "('Result: ' + #integer)",
            "target_property_name": "#text"
        }
    ]
}

The Process

By doing arithmetic operation on strings (except addition), you convert a string into a number.

Notes:

• Instances of strings that is alphanumeric (like a123) will not return 123.
• Adding a string and float (like 'abc' + 1.2) will not produce anything.
• It is not possible to directly display floats—refer to this part of the documentation.

Number to String ​

The following code will create a label that will contain a string number at which will get turned into string.

"label": {
    "type": "label",
    "text": "#text",
    "property_bag": {
        "#num": 10
    },
    "bindings": [
        {
            "binding_type": "view",
            "source_property_name": "('Result: ' + #num)",
            "target_property_name": "#text"
        }
    ]
}

The Process

Doing addition between string and a number will always result a string consisting the combined string and number. In this case, the string is the 'Result: '.

Notes:

• You cannot combine a string and a float, it will produce nothing.

Float to String ​

The following code will create a label that will contain a float data at which will get turned into string.

"label": {
    "type": "label",
    "text": "#text",
    "property_bag": {
        "#float": 6.7
    },
    "bindings": [
        {
            "binding_type": "view",
            "source_property_name": "(0 + (#float > 0) + (#float > 1) + (#float > 2) + (#float > 3) + (#float > 4) + (#float > 5) + (#float > 6) + (#float > 7) + (#float > 8) + (#float > 9))",
            "target_property_name": "#integer"
        },
        {
            "binding_type": "view",
            "source_property_name": "('Result: ' + #integer)",
            "target_property_name": "#text"
        }
    ]
}

The Process

It is not feasible to just add a string and a float as that will produce nothing. Therefore, the binding need to guess where the float lies on between the number 1 to 10.

In this process, it also limits itself into only support floats between 1 to 10 and; the output will not include the decimal number. So in this context, it will only output 6, not 6.7.

Notes:

• There is a way to include the decimal but, it requires a more complex expression.
• The code seen is the simplified version of the concept, there is much more better ways of doing this process.
• This is great if you know the range of your number reference, otherwise, you will need to guess.

Boolean to Number ​

The following code will create a label that will contain a boolean data at which will get turned into number.

"label": {
    "type": "label",
    "text": "#text",
    "property_bag": {
        "#bool": true,
        "#hahasixseven": false
    },
    "bindings": [
        {
            "binding_type": "view",
            "source_property_name": "(#bool + #hahasixseven)",
            "target_property_name": "#integer"
        },
        {
            "binding_type": "view",
            "source_property_name": "('Result: ' + #integer)",
            "target_property_name": "#text"
        }
    ]
}

The Process

Any arithmetic operations done between booleans and numbers will always result a number. Internally, true is recognized as 1, and false is 0. The boolean can be an expression as long as it results as a boolean.