Blob

baja. Blob

A baja:Blob of Bajascript is a wrapper class for raw byte array objects.

Constructor

new Blob(byteArr)

Description:

  • When creating a Blob use make() instead of new Object.
    Constructor should be considered private.

Source:
Since:
  • Niagara 4.14
Parameters:
Name Type Description
byteArr Uint8Array

array of bytes

Extends

Members

(static) DEFAULT

Source:

Methods

byteAt(index) → {Number|undefined}

Source:
Parameters:
Name Type Description
index Number

position of the bytes in the Blob
Returns:

Number if a byte is available at given index else undefined.

Type
Number | undefined

bytesEqual(byteArr) → {boolean}

Description:

  • Checks for equality of bytes in the Blob and input.

Source:
Parameters:
Name Type Description
byteArr Array
Returns:
Type
boolean

copyBytes(arrayToCopy, index) → {Uint8Array}

Description:

  • Returns the blob's byte array with the index position as the pivot.
    In case of an empty array, bytes are copied into it and index position is not considered.

Source:
Parameters:
Name Type Description
arrayToCopy Array
index
Returns:
Type
Uint8Array

decodeAsync(str, batchopt) → {baja.Simple|Promise.<baja.Simple>}

Description:

  • The string encoding of certain Simples may include Type information, or other data that may
    require asynchronous operations to decode. For instance, some Simples may function as
    "containers" for other Simples, and may include that Type information in the string encoding.
    That Simple would then need to import those Types before it could be fully decoded in the
    browser.

    baja.Facets is a great example of this. A Facets may contain FrozenEnum values that are
    defined by Types, such as baja:Weekday. For a Facets containing a Weekday to be fully
    constructed in the browser, the baja:Weekday Type must be imported first. Since importing
    a Type may require a network call, this Facets instance might not be able to be constructed
    synchronously, using only decodeFromString(). baja.Facets has itself implemented
    decodeAsync() to import any necessary Types.

    When implementing a Type Extension for a Simple, if your Simple references arbitrary Types that
    need to be imported when decoding your Simple, implement decodeAsync() and perform any Type
    imports (or other asynchronous operations) there.

    If you are writing code that decodes Simples from strings - that is, when you have a type spec
    and string encoding, and you need to be able to decode any kind of Simple - favor the use of
    decodeAsync, as it gives the individual Simple a chance to perform async operations to ensure
    that the decoded Simple is fully correct.

    The default implementation just returns decodeFromString directly.

    Prior to Niagara 4.14, decodeAsync() was only used in field editors. In 4.14 and later,
    decodeAsync() will be used by BajaScript itself to support asynchronous decoding of Simples
    when resolving ORDs and retrieving other data from the station.

    (Note: decodeAsync() cannot be used by the framework to decode frozen slots. If you
    have a frozen slot, whose definition is a Simple that would require the use of
    decodeAsync() to construct it, it will not work. The best approach would be to implement a
    Type Extension that would use the baja! plugin to preload all the types referenced by the
    default value of that frozen slot, so that decodeFromString would have all the information
    it needed to construct it synchronously.)

Source:
Overrides:
Example
return Promise.resolve(baja.$(simpleTypeSpec).decodeAsync(stringEncoding))
  .then((simpleInstance) => {});
Parameters:
Name Type Attributes Description
str string
batch baja.comm.Batch <optional>

optional batch to use
Returns:

may return the Simple instance
directly, or a Promise resolving to same - so wrap in Promise.resolve()
if unsure.

Type
baja.Simple | Promise.<baja.Simple>

decodeFromString(base64String) → {baja.Blob}

Description:

  • Converts the input string to a Blob.

Source:
Overrides:
Parameters:
Name Type Description
base64String string
Returns:
Type
baja.Blob

encodeToString() → {String}

Description:

  • Returns the Blob as an encoded string.

Source:
Overrides:
Returns:

encoded string

Type
String

equals(obj) → {Boolean}

Description:

  • Equality test.

Source:
Overrides:
Parameters:
Name Type Description
obj
Returns:
Type
Boolean

equivalent(obj) → {Boolean}

Description:

  • Equivalence test.

    equivalent() is used to compare if two Objects have equivalent
    state, but might not want to return true for equals since it
    it has implied semantics for many operations. The default
    implementation returns the result of baja.Object#equals.

Source:
Overrides:
Parameters:
Name Type Description
obj
Returns:
Type
Boolean

getAgents(isopt, batchopt) → {Promise}

Description:

  • Returns a promise that resolves to the agent list for this Object.

Source:
Overrides:
See:
Parameters:
Name Type Attributes Description
is Array.<String> <optional>

An optional array of filters to add to the
agent query.
batch baja.comm.Batch <optional>

An optional object used to batch network
calls together.
Returns:

A promise that will resolve with the Agent Info.

Type
Promise

getBytes() → {Uint8Array}

Source:
Returns:

array of the Blob bytes

Type
Uint8Array

getIcon() → {baja.Icon}

Description:

  • Return the Object's Icon.

Source:
Overrides:
Returns:
Type
baja.Icon

getType() → {Type}

Description:

  • Get the type of this instance.

Source:
Overrides:
Returns:
Type
Type

getTypeDisplayName(cxopt) → {Promise.<string>|string}

Description:

  • Gets the friendly type display name for this object.

Source:
Since:
  • Niagara 4.10
Overrides:
See:
  • baja.Type#getDisplayName
Parameters:
Name Type Attributes Description
cx Object <optional>

a context to be passed down to Type
Returns:

If no context is provided, the type
display name is returned synchronously as a string. If context provided,
the type display name is resolved via a promise as a string.

Type
Promise.<string> | string

length() → {Number}

Source:
Returns:

Byte length of the Blob

Type
Number

make(byteArr) → {baja.Blob}

Description:

  • Makes a Blob.

Source:
Overrides:
Example
// blob can be created with a byte array.
let blob = baja.Blob.make(new Uint8Array([ 1, 2, 3, 4, 5, 6 ]));

// DEFAULT blob can be created with no parameters.
let blob = baja.Blob.make();

// blob can be created as a DEFAULT.
let blob = baja.Blob.DEFAULT;
Parameters:
Name Type Description
byteArr Uint8Array

array of bytes
Returns:
Type
baja.Blob

newCopy(exactopt)

Description:

  • Every value may be cloned using the newCopy method.

    Please note that Simples are immutable so they don't
    allocate a new instance.

Source:
Overrides:
See:
Parameters:
Name Type Attributes Description
exact Boolean <optional>

true if an exact copy of the value should be
made (only valid in the Component architecture).
Returns:

a copy of the value (or the same instance if the value is a
Simple).

toString(cxopt) → {String|Promise.<String>}

Description:

  • Returns the String representation of this object.

Source:
Overrides:
See:
Parameters:
Name Type Attributes Description
cx Object <optional>

optional context information to be used when
formatting the string
Returns:

a string (if no context passed), or
either a string or a Promise (if context passed).

Type
String | Promise.<String>

valueOf() → {String}

Source:
Overrides:
Returns:

the string encoding of the Simple, by default

Type
String

(static) make(byteArr) → {baja.Blob}

Source:
Parameters:
Name Type Description
byteArr Uint8Array
Returns:
Type
baja.Blob

(static) makeBlobFromHexString(hexString) → {baja.Blob}

Description:

  • Makes a Blob from an input hex string.

Source:
Example
let blob = baja.Blob.make('00123a');
Parameters:
Name Type Description
hexString String
Returns:
Type
baja.Blob