I am able to read the file as byte
final bytes = File("path....").readAsBytesSync();
//now, here is the problem
final doc = PdfDocument.load(parserBase);
★ that abstract class PdfDocumentParserBase(bytes) takes Uint8list as its argument which is also a parameter for
PdfDocument.load(parserBase)
, am not good at abstract classes and don't know how to use it in the method.
What I want to achieve is merging multiple pdf files.
Please help me out.
Thanks
Related
Hi is there a method from which I can update a specific line in a file.
My file has data seperated by line break
Sample example to delete line but I have to write everything into file again, can I perform CRUD opertion directly on file lines ?
I want to update specific line in file wihout reading entire file => update string and => write all lines to file.
I may switch to any kind of file type that can offer me this functionality.
Is there a way to store data in row column architecture like sql ?
import 'dart:io';
Future<void> myAsyncFunction() async {
const index = 5;
final File f = File('test.txt');
final List<String> lines = await f.readAsLines();
lines.removeAt(index);
await f.writeAsString(lines.join('\n'));
}
This should be possible by using the String Scanner library, it provides a class called LineScanner and LineScannerState through which you can set the position.
I have not tried this for the exact use case you mention above, so please do evaluate it for your use-case
Files are stored as a contiguous array of bytes on a disk, there is no way to remove a specific line without scanning for newlines and shifting trailing data to fill the void.
For a more sophisticated way of storing data there are many popular database packages, including sqflite, hive, drift, sembast, and objectbox.
How can I get a File from an ImageProvider?
ImageProvider imageProvider = NetworkImage(networkUrl);
File file = imageProvider ?
Although ImageProvider with NetworkImage renders the content of your network image URL, it doesn't have direct APIs or easy way for you to be able to convert it to a File object. With that said, you can still manually cache (or download) the image/s and get the download stream.
As far as I can understand your question, you are trying to access the network image URL as a File object. Instead of using ImageProvider, you can take a look at the flutter_cache_manager, which is a plugin used for downloading and caching files locally, and save it for later use.
Example Usage
Downloading network image file from URL
await DefaultCacheManager().downloadFile(url);
Retrieving File object from the cache dir
// Retrieving File object
var file = await DefaultCacheManager().getSingleFile(imageUrl);
// File object available for use
// Eg. Reading file as string
file.readAsStringSync(...);
Further reading
https://pub.dev/packages/flutter_cache_manager
https://pub.dev/packages/cached_network_image
I am looking for a way to actually get the contents of the file itself, in its text format, dumped. E.g.: i don't want a dictionary object, i don't want some sort of extractionstrategy option, i just want the same text document that itextsharp uses to parse... the WHOLE thing as a string or stringbuilder...
I have not yet found a way to do this using any tools what so ever... my problem is that i am trying to read a dynamic PDF into a C# application... and we all know that those darn dynamic PDFs can't be parsed by iTextSharp (AcroForm and AcroFields always comes up empty), so i figured that if i can get the actual text dump of the entire file, i can see what it looks like and parse it myself for this specific task (e.g.: make a class for each document i know i can received, and make a map there based on what i see).
If anyone can help me do that, or even better, find a way, in C#, to extract the XML Source for the PDF (kinda like clicking the XML Source tab in LiveCycle) instead, it would be greatly appreciated.
Thanks!
Matt
If you are looking for the actual operators and commands of each page in the raw text format, try the following code:
var reader = new PdfReader("test.pdf");
int intPageNum = reader.NumberOfPages;
for (int i = 1; i <= intPageNum; i++)
{
byte[] contentBytes = reader.GetPageContent(i);
File.WriteAllBytes("page-" + i + ".txt", contentBytes);
}
reader.Close();
I am looking for a way to actually get the contents of the file
itself, in its text format, dumped. E.g.: i don't want a dictionary
object, i don't want some sort of extractionstrategy option, i just
want the same text document that itextsharp uses to parse... the WHOLE
thing as a string or stringbuilder...
Unfortunately the data that itextsharp uses to parse are not yet text; the operators in that data are given in some textual format but the actual glyphs may be given in a completely arbitrary ad-hoc encoding. That been said, often some standard encoding is used as it is the most simple solution for the components in use. You cannot in general count on that, though. The answer by VahidN shows you how to access the starting points for that content; not seldomly, though, that page content data he extracts only contain references to resources which are contained in different objects.
my problem is that i am trying to read a dynamic PDF into a C#
application... and we all know that those darn dynamic PDFs can't be
parsed by iTextSharp (AcroForm and AcroFields always comes up empty),
This sounds as if you actually have a completely different task at hand. Dynamic forms and their contents are not part of the page content but instead stored in a separate XML Forms Architecture stream.
iText in Action, 2nd edition, in chapter 8 gives you some information on how to access the XFA stream data, for a first glimps look at the sample XfaMovie.cs.
You might also want to look at the iText XML Worker project for easier manipulation of XFA streams.
if you just want to dump the text, try this:
PdfReader reader = new PdfReader(pdfFileName);
String text = "";
nPages = reader.NumberOfPages;
for (int i = 0; i < nPages; i++)
{
text += PdfTextExtractor.GetTextFromPage(reader, i + 1);
}
I have a code that handles displaying a blob from a local Oracle database. I store both JPG and PDF files as blob. I could view the JPG file, but not the PDF. I have checked these
$self->content_type('image/jpg')
to
$self->content_type('application/pdf').
And the Blob does have data. I checked the length and it has "184546".
All I get when I click the link for the pdf file is a blank page with the title GETIMAGPAGE(application/pdf).
Any help or pointers would be greatly appreciated.
Also, How can we have the content_type to enable two different mime_types? For example in my case both image as well as pdf, depending on what we get?
File::MMagic can recognize the type of data using magic numbers.
use File::MMagic;
$magic = File::MMagic->new;
$self->content($blob);
$self->content_type($magic->checktype_contents($blob));
If you don't want to require a native/plugin PDF reader, perhaps FlexPaper might fit your needs.
I am working on a project where I need to read some generic text...I am looking for any api by I can read generic text and also can convert it to .csv file...
Can any one plz help...
using java on windows os...
--------------------------MORE Detail---------------------------------------------------------------------------------------
let me clarify:
Assume I have a pdf document or for that matter any file type document. I intend to use Print to Generic text printer option and get the file in that format.Finally, I intend to use some API which shoudl enable me to programatically read this Generic Text Format file. I intend to extract text from this generic text file.
So, be it any file (.doc/.pdf/.xls etc wtatever), I intend to create a Generic Text Format file using print option. Then run my code to read those files and extract some information.
PS: Assume that I have a Status report form with standard fields. Ok. But, some people might submit in .pdf, some in .doc , some in text format. But, every document contains same fields, but probably with diferent layouts.
Now, I am looking for a generic solution, by which i shoudl be able to convert every file type in to generic text file format and then apply some logic to extract my Status report fields.
In Java this is more or less what you need to read a text file, assuming it's comma separated (just change the string in the "line.split" method if you need something else). It also skips the header.
public void parse(String filename) throws IOException {
File file = new File(filename);
FileInputStream fis = new FileInputStream(file);
InputStreamReader isr = new InputStreamReader(fis);
BufferedReader br = new BufferedReader(isr);
String line;
int header = 1;
while ((line = br.readLine()) != null) {
if (header == 1) {
header = 2;
continue; // skips header
}
String[] splitter = line.split(",");
// do whatever
System.out.println(splitter[0]);
}
}
CSV is a format for data in columns. It's not very useful for, say, a Wikipedia article.
The Apache Tika library will take all kinds of data and turn it into bland XML, from which you can make CSV as you like.
It would help if you would edit your question to clarify 'generic' versus' generated', and tell more about the data.
As for Windows printer drivers, are you looking to do something like 'print to pdf' as 'print to csv'? If so, I suspect that you need to start from MSDN samples of printer drivers and code this the hard way.
The so-called 'generic text file format' is not a structured format. It's completely unpredictable what you will find in there for any given input to the printer system.
A generic free book: Text Processing in Python
Just used the standard Java classes for I/O:
BufferedWriter, File, FileWriter, IOException, PrintWriter
.csv is simply a comma-separated values file. So just name your output file with a .csv extension.
You'll also need to figure out how you'd like to split your content.
Here are Java examples to get you going:
writing to a text file
how to read lines from a file