Import a local Json File

[Michael Tawiah Sowah]

How do I Import a local Json file in order to use the data

[Andrew Wilson]

You'll probably want to do something like this in your code:

 File file = new File(_kConfigFile);

    final Map<String, List<Map<String, String>>> data =

        file.existsSync()

            ? convert.JSON.decode(

                file.readAsStringSync(),

              )

            : <String, List<Map<String, String>>>{};

And then use the resulting json object to create widgets.

On Fri, Sep 8, 2017 at 10:12 AM, Michael Tawiah Sowah <michael...@gmail.com> wrote:

How do I Import a local Json file in order to use the data

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[Michael Tawiah Sowah]

am confused...a little clarification her please

On Friday, September 8, 2017 at 6:23:57 PM UTC, Andrew Wilson wrote:

You'll probably want to do something like this in your code:

 File file = new File(_kConfigFile);

    final Map<String, List<Map<String, String>>> data =

        file.existsSync()

            ? convert.JSON.decode(

                file.readAsStringSync(),

              )

            : <String, List<Map<String, String>>>{};

And then use the resulting json object to create widgets.

On Fri, Sep 8, 2017 at 10:12 AM, Michael Tawiah Sowah <michael...@gmail.com> wrote:

How do I Import a local Json file in order to use the data

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[Andrew Wilson]

1. You read the file using File (_kConfigFile is the path to the file).

2. You convert the String read from File to json via convert.JSON.decode (you'll need to import dart.convert).

3. Use the resulting Map or List (depending on the contents of the json file) however you want.

-Andrew

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[Michael Tawiah Sowah]

Do I need to declare the file path in pubspec.yaml before I can use it in the File(path);

File file = new File(path); and I keep getting undefined class 'File '

[Seth Ladd]

+Sarah who I believe just added some support for reading in assets?

[Michael Thomsen]

I think we might not support getting a path to an asset right now? I opened a bug for this a few days ago:

https://github.com/flutter/flutter/issues/11892

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[Michael Tawiah Sowah]

where can I get to read

[Andrew Wilson]

If you include the file in assets you can read it with: AssetBundle.loadString(...)

https://docs.flutter.io/flutter/services/AssetBundle/loadString.html

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[Michael Thomsen]

Yes, please ignore my previous answer (which was for cases where you need the file path, not your case where you need the file data).

I added some sample code here:

https://gist.github.com/mit-mit/4ef4ad302bccf5d1b815ed0c25abd451

This assumes you have the data in data/states.json, with contents similar to this:

https://gist.github.com/mit-mit/fad196b7562b4df89206a7e205893496

[Michael Tawiah Sowah]

Thank you so much Michael.

Now I would appreciate also some help on this if you could

https://groups.google.com/forum/#!topic/flutter-dev/c5DgDVc4gbo

[Michael Thomsen]

Sorry, don't have a good answer for that one. But I think you might have better luck getting an answer if you post your question on StackOverflow:

https://stackoverflow.com/questions/tagged/flutter

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[Michael Tawiah Sowah]

Tried that with an earlier question and nothing

[Michael Tawiah Sowah]

Hi Michael, worked well, I was wondering eg: I have a search input at the top of the list and I want to filter through the list as the user types.

On Monday, September 11, 2017 at 10:58:19 AM UTC, Michael Thomsen wrote:

[Si...@prayuta.com]

can u please give example for this

[Michael Thomsen]

This sounds like a perfect question for StackOverflow; have you tried that?

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[Si...@prayuta.com]

add file to assets

add path to assets in pubspec.yaml file

reading  the data  

for example

 var a = await rootBundle.loadString('assets/countries.json');
var b = JSON.decode(a);
  print(JSON.decode(a));
  b.forEach((Map map) => names.add(new NameData.fromJson(map)));
  return  "xyzzy";
  }

[kya...@yathit.com]

I also have same problem reading data file, that work both app and testing.

I found AssetBundle does not work in test.

[Ian Hickson]

We don't create any assets bundles for testing. You might be able to read from disk using the dart:io APIs, though.

--
Ian Hickson

😸

[kufah...@gmail.com]

To anyone who is still searching for a solution:

- I had a JSON file stored in {project_root}/assets/json/quotes.json
- I tried using File.readAsSync() method to put the contents into a Map variable after decoding it: No luck. When I would run my code by using https://marketplace.visualstudio.com/items?itemName=formulahendry.CodeRunner, it would work perfectly. But if I tried using flutter run, it spit out a "cannot find file" error.

- Finally I followed this tutorial and edited the code to suit my purpose. You can see my json file (it's minified) here and the code that gets a random quote from value from the json list + puts the whole thing into a ListView() here.

Note: I just discovered that Bram (same guy as above) seems to have created a nice tutorial that would do what I wanted to do using File(), but he adds a dependency so he can get the right directory. See the code here: https://github.com/bramvbilsen/Flutter-JSON-Storage-Tutorial/blob/master/lib/main.dart ad the vid here: https://www.youtube.com/watch?v=jVVCHzkI8as

Hope this helps.

[ma...@didierboelens.com]

Hi Kifah,

Very small comment on your code, if I may.

JSON.decode has been deprecated and we should now use json.decode, instead.

Regards, 

Didier