JSON function in PowerApps

Generates a JSON text string for a table, a record, or a value.

Description

The JSON function returns the JavaScript Object Notation (JSON) representation of a data structure as text so that it's suitable for storing or transmitting across a network. ECMA-404 and IETF RFC 8259 describe the format, which is widely used by JavaScript and other programming languages.

Canvas apps support the data types that this table lists with details about their text representation:

Data type Description Result example
Boolean true or false. true
Color String that contains the 8-digit hexadecimal representation for the color. This representation takes the format #rrggbbaa, where rr is the red component, gg is green, bb is blue, and aa is the alpha channel. For the alpha channel, 00 is fully transparent, and ff is fully opaque. You can pass the string to the ColorValue function. "#102030ff"
Currency Number that uses the appropriate decimal separator for the user's language. Scientific notation is used if needed. 1.345
Date String that contains the date in ISO 8601 yyyy-mm-dd format. "2019-03-31"
DateTime String that contains an ISO 8601 date/time. Date/time values are in UTC, as the ending "Z" indicates. "2019-03-31T22:32:06.822Z"
GUID String that contains the GUID value. Letters are lowercase. "751b58ac-380e-4a04-a925-9f375995cc40"
Image, Media If IncludeBinaryData is specified, media files are encoded in a string. Web references that use the http: or https: URL scheme aren't modified. References to in-memory binary data are encoded with the "data:mimetype;base64,..." format. In-memory data includes images that users capture by using the Camera control and any other references with the appres: and blob: URL schemes. "data:image/jpeg;base64,/9j/4AA..."
Number Number that uses the appropriate decimal separator for the user's language. Scientific notation is used if needed. 1.345
Option set Numeric value of the option set, not the label that's used for display. The numeric value is used because it's language independent. 1001
Time String that contains an ISO 8601 hh:mm:ss.fff format. "23:12:49.000"
Record Comma-delimited list, between { and }, of fields and their values. This notation resembles that for records in canvas apps, but the name is always between double quotation marks. This format doesn't support records that are based on many-to-one relationships. { "First Name": "Fred", "Age": 21 }
Table Comma-delimited list, between [ and ], of records. This format doesn't support tables that are based on one-to-many relationships. [ { "First Name": "Fred", "Age": 21 }, { "First Name": "Jean", "Age": 20 } ]
Two option Boolean value of the two option, true or false, not the label that's used for display. The Boolean value is used because it's language independent. false
Hyperlink, Text String between double quotation marks. The function escapes embedded double-quotation marks with a backslash, replaces newlines with "\n", and makes other standard JavaScript replacements. "This is a string."

Specify the optional Format argument to control how readable the result is and how unsupported and binary data types are handled. By default, the output is as compact as possible with no unnecessary spaces or newlines, and unsupported data types and binary data aren't allowed. You can combine multiple formats if you specify the & operator.

JSONFormat enum Description
Compact Default. The output is as compact as possible with no added spaces or newlines.
IndentFour To improve readability, the output contains a newline for each column and nesting level and uses four spaces for each indentation level.
IncludeBinaryData The result includes image, video, and audio-clip columns. This format can dramatically increase the result's size and degrade your app's performance.
IgnoreBinaryData The result doesn't include image, video, or audio-clip columns. If you specify neither IncludeBinaryData nor IgnoreBinaryData, the function produces an error if it encounters binary data.
IgnoreUnsupportedTypes Unsupported data types are allowed, but the result won't include them. By default, unsupported data types produce an error.

Use the ShowColumns and DropColumns functions to control which data the result includes and to remove unsupported data types.

Because JSON can be both memory and compute intensive, you can use this function only in behavior functions. You can capture the result from JSON into a variable, which you can then use in data flow.

If a column has both a display name and a logical name, the result contains the logical name. Display names reflect the language of the app user and are, therefore, inappropriate for data transfer to a common service.

Syntax

JSON( DataStructure [, Format ] )

  • DataStructure – Required. The data structure to convert to JSON. Tables, records, and primitive values are supported, arbitrarily nested.
  • Format - Optional. JSONFormat enum value. The default value is Compact, which doesn't add newlines or spaces and blocks binary data and unsupported columns.

Examples

Hierarchical data

  1. Insert a Button control, and set its OnSelect property to this formula.

    ClearCollect( CityPopulations,
        { City: "London",    Country: "United Kingdom", Population: 8615000 },
        { City: "Berlin",    Country: "Germany",        Population: 3562000 },
        { City: "Madrid",    Country: "Spain",          Population: 3165000 },
        { City: "Hamburg",   Country: "Germany",        Population: 1760000 },
        { City: "Barcelona", Country: "Spain",          Population: 1602000 },
        { City: "Munich",    Country: "Germany",        Population: 1494000 }
    );
    ClearCollect( CitiesByCountry, GroupBy( CityPopulations, "Country", "Cities" ) )
    
  2. Select the button while holding down the Alt key.

    The CitiesByCountry collection is created with this data structure, which you can show by selecting Collections on the File menu and then selecting the name of the collection.

    CitiesByCountry collection

    You can also show this collection by selecting File > App settings > Advanced settings > Enable formula bar result view, selecting the name of the collection in the formula bar, and then selecting the down arrow next to the name of the collection under the formula bar.

    Collection in the formula bar's result view

  3. Insert another button, and set its OnSelect property to this formula:

    Set( CitiesByCountryJSON, JSON( CitiesByCountry ) )
    

    This formula sets the global variable CitiesByCountryJSON to the JSON representation for CitiesByCountry.

  4. Select the button while holding down the Alt key.

  5. Insert a Label control, and set its Text property to this variable.

    CitiesByCountryJSON
    

    The label shows this result, all on a single line with no spaces, suitable for transmission across a network:

    [{"Cities":[{"City":"London","Population":8615000}],"Country":"United Kingdom"},{"Cities":[{"City":"Berlin","Population":3562000},{"City":"Hamburg","Population":1760000},{"City":"Munich","Population":1494000}],"Country":"Germany"},{"Cities":[{"City":"Madrid","Population":3165000},{"City":"Barcelona","Population":1602000}],"Country":"Spain"}]
    
  6. Change the second button's formula to make the output more readable.

    Set( CitiesByCountryJSON, JSON(CitiesByCountry, JSONFormat.IndentFour ))
    
  7. Select the second button while holding down the Alt key.

    The label shows the more readable result.

    [
        {
            "Cities": [
                {
                    "City": "London",
                    "Population": 8615000
                }
            ],
            "Country": "United Kingdom"
        },
        {
            "Cities": [
                {
                    "City": "Berlin",
                    "Population": 3562000
                },
                {
                    "City": "Hamburg",
                    "Population": 1760000
                },
                {
                    "City": "Munich",
                    "Population": 1494000
                }
            ],
            "Country": "Germany"
        },
        {
            "Cities": [
                {
                    "City": "Madrid",
                    "Population": 3165000
                },
                {
                    "City": "Barcelona",
                    "Population": 1602000
                }
            ],
            "Country": "Spain"
        }
    ]
    

Images and media in base64

  1. Add an Image control.

    This control brings SampleImage with it.

  2. Add a Button control, and set its OnSelect property to this formula.

    Set( ImageJSON, JSON( SampleImage, JSONFormat.IncludeBinaryData ) )
    
  3. Select the button while holding down the Alt key.

  4. Add a label, and set its Text property to this variable.

    ImageJSON
    
  5. Resize the control and reduce the font size as needed to show most of the result.

    The label shows the text string that the JSON function captured.

    "data:image/svg+xml;base64,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"