Open the app with the specific file

2023-03-18 hit count image

this blog post is about how to open RN(React Native) app with the specific file(like excel, powerpoint, etc).

Outline

sometimes, we download the specific file from the web or the email, and want to open them with our app. for example, open the specific app with pdf file or excel file like below.

in Android,

Android - open the app with file

in iOS,

iOS - open the app with file

this blog is about how to open your app when we open the specific file like above and how to use the specific file in your app. in this blog, we’ll use .temp file to execute the app.

iOS

let’s activate iTunes file share feature to check the specific file is copied well in iOS.

and then, modify ios/[project name]/Info.plist like below to open the app with the specific file on iOS.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  ...
  <!-- custom file start -->
	<key>UTExportedTypeDeclarations</key>
	<array>
		<dict>
			<key>UTTypeConformsTo</key>
			<array>
				<string>public.data</string>
			</array>
			<key>UTTypeDescription</key>
			<string>Custom File</string>
			<key>UTTypeIdentifier</key>
			<!-- change custom file extension -->
			<string>com.example.document.temp</string>
			<key>UTTypeTagSpecification</key>
			<dict>
				<key>public.filename-extension</key>
				<!-- change custom file extension -->
				<array>
					<string>temp</string>
				</array>
			</dict>
		</dict>
	</array>
	<key>CFBundleDocumentTypes</key>
	<array>
		<dict>
			<key>CFBundleTypeName</key>
			<string>Custom File</string>
			<key>CFBundleTypeRole</key>
			<string>Editor</string>
			<key>LSHandlerRank</key>
			<string>Owner</string>
			<key>LSItemContentTypes</key>
			<array>
				<!-- change custom file extension -->
				<string>com.example.document.temp</string>
			</array>
		</dict>
	</array>
	<!-- custom file end -->
  ...
</dict>
</plist>

I mention again, above is to open the app with .temp file. change 3 parts(<!-- change custom file extension --> comments) to the file type you want to use.

first, open iTunes to check the file share feature is activated.

iOS - check itunes file share feature

for testing, change a file name to .temp and send an email with it. open the email app on iOS and select .temp file. when you click the share button on the right top, you can see that you can copy the file to your app.

iOS - open the app with the custom file

if you select your app, the file will be copied in your app.

open iTunes again, and select your app. you cann see Inbox folder is created.

iOS - check file is copied on itunes

copy that folder to outside. you can see the same file which you sent via the email.

iOS - check the inbox file

Android

Android is more difficult than iOS. first, add Intent Filter in android/app/src/main/AndroidManifest.xml.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.react_native_open_file_with">
  ...
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
        <!-- custom file start -->
        <intent-filter
          android:icon="@mipmap/ic_launcher"
          android:label="@string/app_name">
            <action android:name="android.intent.action.VIEW" />
            <action android:name="android.intent.action.EDIT" />
            <category android:name="android.intent.category.DEFAULT" />
            <!-- change custom file extension -->
            <data
              android:mimeType="*/*"
              android:host="*"
              android:pathPattern=".*\\.temp"
            />
        </intent-filter>
        <!-- custom file end -->
  ...
</manifest>

in here also, you would change .temp to the file name that you want to use. open and edit MainActivity.java file like below.

...
import android.content.ContentResolver;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.net.Uri;
import android.provider.MediaStore;
import android.util.Log;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
...

public class MainActivity extends ReactActivity {
    ...
    @Override
    protected void onResume() {
        super.onResume();
        Uri data = getIntent().getData();
        if(data != null) {
            try {
                importData(data);
            }catch (Exception e) {
                Log.e("File Import Error", e.getMessage());
            }
        }
    }

    private void importData(Uri data) {
        final String scheme = data.getScheme();

        if (ContentResolver.SCHEME_CONTENT.equals(scheme)) {
            try {
                ContentResolver cr = getApplicationContext().getContentResolver();
                InputStream is = cr.openInputStream(data);
                if(is == null) return;

                String name = getContentName(cr, data);

                PackageManager m = getPackageManager();
                String s = getPackageName();
                PackageInfo p = m.getPackageInfo(s, 0);
                s = p.applicationInfo.dataDir;

                InputStreamToFile(is, s + "/files/" + name);
            } catch (Exception e) {
                Log.e("File Import Error", e.getMessage());
            }
        }
    }

    private String getContentName(ContentResolver resolver, Uri uri){
        Cursor cursor = resolver.query(uri, null, null, null, null);
        cursor.moveToFirst();
        int nameIndex = cursor.getColumnIndex(MediaStore.MediaColumns.DISPLAY_NAME);
        if (nameIndex >= 0) {
            return cursor.getString(nameIndex);
        } else {
            return null;
        }
    }

    private void InputStreamToFile(InputStream in, String file) {
        try {
            OutputStream out = new FileOutputStream(new File(file));

            int size = 0;
            byte[] buffer = new byte[1024];

            while ((size = in.read(buffer)) != -1) {
                out.write(buffer, 0, size);
            }

            out.close();
        }
        catch (Exception e) {
            Log.e("MainActivity", "InputStreamToFile exception: " + e.getMessage());
        }
    }
    ...
}

above is when you open the app with the file, copy the file to your app. on iOS, the file is copied automatically, but on Android, we need the code the file is copied on the app.

rename any file to .temp and send the email with it like iOS test. open the email app and select .temp file that you sent or download the file and select it. you can see your app on the copy menu.

Android - open the app with the custom file

the file is copied when you select your app on the menu. the file is located on /data/user/0/[app package name]/files.

How To Use.

let’s see how to use the file that is copied on above with react-native-fs. I’ll use RN(React Native) project that applied below list. if you want to know more details, see the links.

you can see full source code on the repository below.

you can see how to install react-native-fs on the blog post below.

let’s see the main part of the source code.

private _DOCUMENT_PATH = RNFS.DocumentDirectoryPath;

you can access the copied file by RNFS.DocumentDirectoryPath.

private _loadFiles = async () => {
    if (Platform.OS === 'ios') {
        await this._moveInboxFiles();
    }

    RNFS.readDir(this._DOCUMENT_PATH)
    .then((srcFiles: Array<RNFS.ReadDirItem>) => {
        let files: Array<RNFS.ReadDirItem> = [];
        srcFiles.map((file: RNFS.ReadDirItem) => {
            if (file.isFile() && file.name.indexOf('.temp') >= 0) {
                files.push(file);
            }
        });
        this.setState({ files });
    })
    .catch(err => {
        console.log(err.message, err.code);
    });
};

read the folder and if it is the file, push the file to the file list. in iOS, the file is located on Inbox in RNFS.DocumentDirectoryPath. so, before reading the files, copy the files from Inbox.

private _moveInboxFiles = async () => {
    try {
        const inboxFiles = await RNFS.readDir(this._DOCUMENT_PATH + '/Inbox');
        if (inboxFiles) {
            inboxFiles.map(async file => {
                if (file.isFile()) {
                    if (file.isFile()) {
                        await RNFS.moveFile(
                        file.path,
                        `${this._DOCUMENT_PATH}/${file.name}`
                        );
                    }
                }
            });
        }
    } catch (err) {
        console.log(err.message, err.code);
    }
};

these files have the information below. you can use them.

const { ctime, mtime, path, name, size } = file;

Test On iOS Simulator

let’s see how to test on iOS simulator. after executing the simulator, execute the code below to get the simulator id.

xcrun simctl list | egrep '(Booted)'

I made npm command in my repository. check package.json.

npm run get-id
iPhone X (5C0277D7-12FA-42DE-AD6D-AC3C74324B4C) (Booted)

after executing the command, you can get the simulator id.

cd /Users/[user name]/Library/Developer/CoreSimulator/Devices/5C0277D7-12FA-42DE-AD6D-AC3C74324B4C/data/Containers/Data/Application/
open .

you can see the app created at today on the folder above. copy the file to Documents folder in the app folder.

copy the file to the simulator

after it, execute the app or if you use my repository, select the refresh button on the right top.

iOS - show file list on the simulator

after then, you can see the file list like above.

Test on Android

I’ve tested Android on the device. you can see the file list is displayed well on Android.

Android - show file list on Android device

Completed

recently, we save and use all files on the servers, so this feature may not be needed. however, I think someday we can use it if we know it. we saw how to open the app with the specific file and use it. I hope this blog post is helpful for someone to implement to open the app with a specific file.

Was my blog helpful? Please leave a comment at the bottom. it will be a great help to me!

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