PDFObject¶

All functions that take a PDFObject apply an automatic translation between Javascript objects and PDFObject using a few basic rules:

null, true, false, and numbers are translated directly.
Strings are translated to PDF names, unless they are surrounded by parentheses: "Foo" becomes the /Foo and "(Foo)" becomes (Foo).
Arrays and dictionaries are recursively translated to PDF arrays and dictionaries. Be aware of cycles though! The translation does NOT cope with cyclic references!

only mutool run This automatic translation goes both ways – entries of PDF dictionaries and arrays can be accessed like Javascript objects and arrays.

Constructors¶

class PDFObject()¶: You cannot create instances of this class with the new operator!

Use the methods on a PDFDocument instance to create new objects.

Instance properties¶

PDFObject.prototype.length¶: Number of entries in array PDFObjects. Zero for all other object types.

PDFObject.prototype.[n]¶

only mutool run

Get or set the element at index n in an array (0-indexed).

See PDFObject.prototype.get() and PDFObject.prototype.put() for the equivalent in mupdf.js.

Throws:: Error on out of bounds accesses.

var pdfObject = pdfDocument.newArray()
pdfObject[0] = "hello"
pdfObject[1] = "world"

PDFObject.prototype.[name]¶

only mutool run

Access a key named name in a dictionary. It is both possible to get and set its value, but also delete the key entirely.

See PDFObject.prototype.get(), PDFObject.prototype.put(), and PDFObject.prototype.delete() for the equivalent in mupdf.js.

var pages = doc.getTrailer().Root.Pages
pages.Hello = "world"
pages["Xyzzy"] = 42
delete pages["Hello"]
delete pages.Xyzzy

Instance methods¶

PDFObject.prototype.get(...path)¶

Access dictionaries and arrays in the PDFObject.

Returns null if the dictionary key does not exist, or if the array index is out of range.

Arguments:

...path (Array) – The path.

Returns:

PDFObject | null

var dict = pdfDocument.newDictionary()
var value = dict.get("my_key")
var arr = pdfDocument.newArray()
var value = arr.get(1)
var page7 = pdfDocument.getTrailer().get("Root", "Pages", "Kids", 7)

PDFObject.prototype.getInheritable(key)¶

For a dictionary, if the requested key does not exist, getInheritable() will walk Parent references to parent dictionaries and lookup the same key there.

If no key can be found in any parent or grand-parent or grand-grand-parent, all the way up, null is returned.

Arguments:

key (PDFObject | string)

Returns:

PDFObject | null

var page = pdfDocument.loadPage(0)
var pageObj = page.getObject()
var rotate = pageObj.getInheritable("Rotate")

PDFObject.prototype.put(key, value)¶

Set values in PDFObject dictionaries or arrays.

Arguments:

key (PDFObject | string | number) – Interpreted as an index for arrays or a key string for dictionaries.
value (PDFObject | Array | string | number | boolean | null) – The value to set at the array index or for dictionary key.

var dict = pdfDocument.newDictionary()
dict.put("my_key", "my_value")
var arr = pdfDocument.newArray()
arr.put(0, 42)

PDFObject.prototype.delete(key)¶

Delete a reference from a PDFObject.

Arguments:

key (number | string | PDFObject)

var dict = pdfDocument.newDictionary()
dict.put("my_key", "my_value")
dict.delete("my_key")
var arr = pdfDocument.newArray()
arr.put(1, 42)
arr.delete(1)

PDFObject.prototype.resolve()¶

If the object is an indirect reference, return the object it points to; otherwise return the object itself.

Returns:: PDFObject

var resolvedObj = obj.resolve()

PDFObject.prototype.isArray()¶

Returns:: boolean

var result = obj.isArray()

PDFObject.prototype.isDictionary()¶

Returns:: boolean

var result = obj.isDictionary()

PDFObject.prototype.forEach(callback)¶

Iterate over all the entries in a dictionary or array and call a function for each value-key pair.

Arguments:

callback – (val: PDFObject, key: number | string, self: PDFObject) => void

obj.forEach(function (value, key) {
        console.log("value="+value+",key="+key)
})

PDFObject.prototype.push(item)¶

Append item to the end of the object.

Arguments:

item (PDFObject)

obj.push("item")

PDFObject.prototype.toString(tight, ascii)¶

Returns the object as a pretty-printed string.

Arguments:

tight (boolean) – Whether to print the object as tightly as possible, or as human-readably as possible.
ascii (boolean) – Whether to print binary data as ascii or as binary data.

Returns:

string

var str = obj.toString()

PDFObject.prototype.valueOf()¶

Try to convert a PDF object into a corresponding primitive Javascript value.

Indirect references are converted to the string “obj 0 R” where obj is the PDF object’s object number.

Names are converted to strings.

Arrays and dictionaries are not converted.

Returns:: A Javascript value or this.

var val = obj.valueOf()

PDFObject.prototype.compare(other_obj)¶

only mutool run

Compare the object to another one. Returns 0 on match, non-zero on mismatch.

Arguments:

other (PDFObject)

Returns:

number

var match = pdfObj.compare(other_obj)

Streams¶

The only way to access a stream is via an indirect object, since all streams are numbered objects.

PDFObject.prototype.isStream()¶

Returns whether the object is an indirect reference pointing to a stream.

Returns:: boolean

var val = obj.isStream()

PDFObject.prototype.readStream()¶

Read the contents of the stream object into a Buffer.

Returns:: Buffer

var buffer = obj.readStream()

PDFObject.prototype.readRawStream()¶

Read the raw, uncompressed, contents of the stream object into a Buffer.

Returns:: Buffer

var buffer = obj.readRawStream()

PDFObject.prototype.writeObject(obj)¶

Update the object the indirect reference points to.

Arguments:

obj (PDFObject)

obj.writeObject(obj)

PDFObject.prototype.writeStream(buf)¶

Update the contents of the stream the indirect reference points to. This will update the “Length”, “Filter” and “DecodeParms” automatically.

Arguments:

buf (Buffer | ArrayBuffer | Uint8Array)

obj.writeStream(buffer)

PDFObject.prototype.writeRawStream(buf)¶

Update the contents of the stream the indirect reference points to. The buffer must contain already compressed data that matches the “Filter” and “DecodeParms”. This will update the “Length” automatically, but leave the “Filter” and “DecodeParms” untouched.

Arguments:

buf (Buffer | ArrayBuffer | Uint8Array)

obj.writeRawStream(buffer)

Primitive Objects¶

Primitive PDF objects such as booleans, names, and numbers can usually be treated like Javascript values (thanks to valueOf). When that is not sufficient use these functions:

PDFObject.prototype.isNull()¶

Returns true if the object is null.

Returns:: boolean

var val = obj.isNull()

PDFObject.prototype.isBoolean()¶

Returns whether the object is a boolean.

Returns:: boolean

var val = obj.isBoolean()

PDFObject.prototype.asBoolean()¶

Get the boolean primitive value.

Returns:: boolean

var val = obj.asBoolean()

PDFObject.prototype.isInteger()¶

Returns whether the object is an integer.

Returns:: boolean

var val = obj.isInteger()

PDFObject.prototype.isReal()¶

Returns whether the object is a PDF real number.

Returns:: boolean

var val = pdfObj.isReal()

PDFObject.prototype.isNumber()¶

Returns whether the object is a number (an integer or a real).

Returns:: boolean

var val = obj.isNumber()

PDFObject.prototype.asNumber()¶

Get the number primitive value.

Returns:: number

var val = obj.asNumber()

PDFObject.prototype.isName()¶

Returns whether the object is a name.

Returns:: boolean

var val = obj.isName()

PDFObject.prototype.asName()¶

Get the name as a string.

Returns:: string

var val = obj.asName()

PDFObject.prototype.isString()¶

Returns whether the object is a string.

Returns:: boolean

var val = obj.isString()

PDFObject.prototype.asString()¶

Convert a “text string” to a Javascript unicode string.

Returns:: string

var val = obj.asString()

PDFObject.prototype.asByteString()¶

Convert a string to an array of byte values.

Returns:: Uint8Array | Array of number

var val = obj.asByteString()

PDFObject.prototype.isIndirect()¶

Is the object an indirect reference.

Returns:: boolean

var val = obj.isIndirect()

PDFObject.prototype.asIndirect()¶

Return the object number the indirect reference points to.

Returns:: number

var val = obj.asIndirect()