The number of bytes contained in the buffer is found by invoking the length method. In files where you want to use base64 encodingdecoding, simply include the header file and use one of the provided nsdata or nsstring additions. So lets utilize our awesome method swizzling to be able to configure the description of nsdata. Addobservernsobject, nsstring, nskeyvalueobservingoptions, intptr. If you want to convert string to nsdata using nsutf8stringencoding. Nsdata can be represented as hexadecimal string, similar to what it outputs in its description method swift. This function returns nil if the encoding is not correct. Nsdictionary pdf nsdata nsdata nsdata stringdouble. In essence, nsdata is an objectivec wrapper around a c data buffer.
You can serialize the object to a byte array, then use that to create the nsdata object and get the byte array back out when you need it again you could also serialize the object to a string with for example, then create the nsdata from the string. To go back the other way, from a base64 encoded nsstring object to an nsdata object is as easy as calling the method initwithbase64encodedstring, passing in the base64 encoded nsstring lines 1415. Am assuming you have your pdf in documents directory here. String this is my string to convert to nsdata let utf8str stri. Nsdata and nsstring saving data in ios raywenderlich. Line 6 encodes the data and returns an nsstring object. In this post ill do the opposite, putting the conversion into the context how to print an nsdata object to the debugging console by default, when you print an nsdata object to the console using nslog, the output will be in hex, it will look something like the following. Readingoptions nsdata apple developer documentation. In the previous post i wrote a few lines of code to convert an nsstring object to an nsdata object. Nsdatensstring nsstring nsstring nsstring nsstring nsstring nsstring nsstring nsstring nsstring nsstring cfstringref. We can usensstring datausingencoding function to convert nsstring to nsdata.
If you need to read potentially large files, use input stream with url. A pdf document object can be constructed with an existing pdf file from a file path, memory buffer, a custom implemented readercallback object and an input file stream. The returned object may be different from the original receiver. Ill also throw in an optimal nsdatatohexstring method for good measure, hopefully to help counteract the awful practice some developers have adopted of using the nsdata description for that serialization. Provide me any good code example of converting nsdata to nsstring. Nsdata write to pdf you can convert nsdata to pdf with bellow code. In listing 31, the document data is plain text, so an nsstring property is all that is needed to hold it.
All lengths, character indexes, and ranges are expressed in terms of 16bit platformendian values, with index values starting at 0 an nsstring object can be initialized from or written to a c buffer, an nsdata object, or the contents of an nsurl. This should work to swap each pair of adjacent bytes in the data. I get the bellow code from this link nsstring stringnsstring. Convert string to nsdata and nsdata to string swift findnerd. Hot network questions is it possible to connect an old rj11 phone line into a cat 6 wall socket to use for fttn service. Convert string to nsdata and nsdata to string swift. I generated a pdf file in my program and i have it here. An nsstring object initialized by converting the bytes in data into utf16 code units using encoding. Nsdata provides methods for atomically saving their contents to a file, which guarantee that the data is either saved in its entirety, or it fails completely. Data objects let simple allocated buffers that is, data with no embedded pointers take on the behavior of foundation objects. Try this to convert pdf to nsdata nsstring pdfpath documentsdirectory stringbyappendingpathcomponent.
The idea is to interpret the bytes as an array of uint16 integers and use the builtin byteswapped property. For instance, if you store a file on a server and download the same onto a device, you can compare the server hosted md5 value to a received copy to verify the file was. Jan 24, 2014 on line 2 we create the nsdata to encode. Objectivec language encoding and decoding a string. Sep 22, 2014 nsdata and its mutable subclass nsmutabledata provide data objects, objectoriented wrappers for byte buffers. Base64 encode and decode nsdata and nsstring objects. By continuing to use pastebin, you agree to our use of cookies as described in the cookies policy. Developer guide for foxit pdf sdk for mac objectivec. Instead of printing the pdf file using device printer, create your own callbacks to write into the file and save the file in custom location.
An atomic write first writes the data to a temporary file and then, only if this write succeeds, moves the temporary file to its final location. Encoding and decoding a string using nsdata base64. With the support of native webview and webviewclient, you can create your own print document adapter where you can customize your pdf file as required. How to generate pdf using nsdata or using data bytes objective c. Constants 25 nsdatareadingoptions 25 nsdatawritingoptions 26 nsdatasearchoptions 26 appendixa deprecatednsdatamethods29 deprecatedinios4. How to convert nsstring back to nsdata after converting nsdata to nsstring. This answer is wrong when str contains code points larger than 127. Nsdata and its mutable subclass nsmutabledata provide data objects, objectoriented wrappers for byte buffers. An nsstring object can be initialized from or written to a c buffer, an nsdata object, or the contents of an nsurl. You answered your own question pretty well, except that stringwithutf8string. Extends string class import foundation extension string func base64encoded string let plaindata datausingencodingnsutf8stringencoding let base64string plaindatabase64encodedstringwithoptionsomraw0.
To go back the other way, from a base64 encoded nsstring object to an nsdata object is as easy as calling the method initwithbase64encodedstring, passing in the base64 encoded nsstring lines 1415 lines 1820 go from the base64 nsdata object back to an nsstring which is how we. The text will be converted to an nsdata object that is written to the document file. To access the buffer directly, use the bytes method, which returns a pointer to the buffer. Nsdata can be represented as hexadecimal string, similar to what it outputs in its description method swift extension nsdata func hexstring string return unsafebufferpointer start. Nsdata hexadecimal pdf download objectivec language for free. Nsdata write to pdf nsdata write to pdf nsdata write to pdf download. With your help i basically finished my project enough to.
Uiwebview nsdata responsedata nsurlconnection sendsynchronousrequest. Converting nsdata to nsstring in objective c stack overflow. Adding methods to nsdata and nsstring using categories to. Its a common question among ios developers, how do i convert an nsstring object to an nsdata object the. I got the same error, the above solution didnt work for me, in my case i was calling datawithcontentsofurl from within a unnotificationserviceextension so i had to update the info. I did the following, nsstring string nsstring stringwithformat. Sep 23, 2019 we can convert into nsstring let strjson. Additionally, nsdata provides a handful of methods for copy bytes from the data object into a buffer. Reading options a hint indicating the file should be mapped into virtual memory, if possible and safe. It can also be encoded and decoded to and from ascii, utf8, utf16, utf32, or any other string encoding represented by nsstring encoding. I have a problem converting a file blob comming from a webservice to an nsdata object.
Nsdata creates static data objects, and nsmutabledata creates dynamic data objects. Pdf nsnumber nsnumber nsdata nsdata nsdata stringdouble. Nsdata and its mutable subclass nsmutable data provide data objects, or objectoriented wrappers for byte buffers. Nsstring the nsstring class and its mutable subclass, nsmutablestring, provide an extensive set of apis for working with strings, including methods for comparing, searching, and modifying strings. Creates a data object containing the data from the location specified by a given url. Hi readers,this blog includes the concept of converting nsdata to uiimage with the help of a very simple example. You can also use it to read short files synchronously. Returns nil if the initialization fails for some reason for example if data does not represent valid data for encoding. How to generate a pdf file from html string in xamarin forms.
Create md5 hash from nsstring, nsdata or a file md5 messagedigest algorithm 5 is a crytographic hash function that is commonly used as a means to verify file integrity. When you have some data which is encoded in utf8 data than you can use below code. I tried using getting as nsdata as well, but i get null back. I have utf8 encoded nsdata from windows server and i want to convert it to nsstring for iphone. Get nsstring from nsdata object in base64 nsstring base64encoded nsdata base64encodedstringwithoptions. Matts answer should take care of it, but if it absolutely doesnt and youre somehow absolutely sure that your nsdata object has valid string data in it then you can access the data directly via the data bytes method, build a traditional c stri. This method may fail and return nil for various reasons, like bad urls and filenotfound errors. Nsdata and nsmutabledata are typically used for data.
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