Added API calls for downloading files at version and getting concatenated file diffs (#101)

Fixes #93

Author: erpas

mergin/cli.py

@@ -26,6 +26,8 @@
 from mergin.client_pull import (
     download_project_async,
     download_project_cancel,
+    download_file_async,
+    download_file_finalize,
     download_project_finalize,
     download_project_is_running,
 )
@@ -260,6 +262,41 @@ def download(ctx, project, directory, version):
         _print_unhandled_exception()
 
 
+@cli.command()
+@click.argument("filepath")
+@click.argument("output")
+@click.option("--version", help="Project version tag, for example 'v3'")
+@click.pass_context
+def download_file(ctx, filepath, output, version):
+    """
+    Download project file at specified version. `project` needs to be a combination of namespace/project.
+    If no version is given, the latest will be fetched.
+    """
+    mc = ctx.obj["client"]
+    if mc is None:
+        return
+    mp = MerginProject(os.getcwd())
+    project_path = mp.metadata["name"]
+    try:
+        job = download_file_async(mc, project_path, filepath, output, version)
+        with click.progressbar(length=job.total_size) as bar:
+            last_transferred_size = 0
+            while download_project_is_running(job):
+                time.sleep(1 / 10)  # 100ms
+                new_transferred_size = job.transferred_size
+                bar.update(new_transferred_size - last_transferred_size)  # the update() needs increment only
+                last_transferred_size = new_transferred_size
+        download_file_finalize(job)
+        click.echo("Done")
+    except KeyboardInterrupt:
+        click.secho("Cancelling...")
+        download_project_cancel(job)
+    except ClientError as e:
+        click.secho("Error: " + str(e), fg="red")
+    except Exception as e:
+        _print_unhandled_exception()
+
+
 def num_version(name):
     return int(name.lstrip("v"))
 

mergin/client.py

@@ -11,12 +11,20 @@
 import dateutil.parser
 import ssl
 
-from .common import ClientError, LoginError
+from .common import ClientError, LoginError, InvalidProject
 from .merginproject import MerginProject
-from .client_pull import download_project_async, download_project_wait, download_project_finalize
+from .client_pull import (
+    download_file_finalize,
+    download_project_async,
+    download_file_async,
+    download_diffs_async,
+    download_project_finalize,
+    download_project_wait,
+    download_diffs_finalize,
+)
 from .client_pull import pull_project_async, pull_project_wait, pull_project_finalize
 from .client_push import push_project_async, push_project_wait, push_project_finalize
-from .utils import DateTimeEncoder
+from .utils import DateTimeEncoder, get_versions_with_file_changes
 from .version import __version__
 
 this_dir = os.path.dirname(os.path.realpath(__file__))
@@ -618,3 +626,38 @@ def get_projects_by_names(self, projects):
 
         resp = self.post("/v1/project/by_names", {"projects": projects}, {"Content-Type": "application/json"})
         return json.load(resp)
+
+    def download_file(self, project_dir, file_path, output_filename, version=None):
+        """
+        Download project file at specified version. Get the latest if no version specified.
+
+        :param project_dir: project local directory
+        :type project_dir: String
+        :param file_path: relative path of file to download in the project directory
+        :type file_path: String
+        :param output_filename: full destination path for saving the downloaded file
+        :type output_filename: String
+        :param version: optional version tag for downloaded file
+        :type version: String
+        """
+        job = download_file_async(self, project_dir, file_path, output_filename, version=version)
+        pull_project_wait(job)
+        download_file_finalize(job)
+
+    def get_file_diff(self, project_dir, file_path, output_diff, version_from, version_to):
+        """ Create concatenated diff for project file diffs between versions version_from and version_to.
+
+        :param project_dir: project local directory
+        :type project_dir: String
+        :param file_path: relative path of file to download in the project directory
+        :type file_path: String
+        :param output_diff: full destination path for concatenated diff file
+        :type output_diff: String
+        :param version_from: starting project version tag for getting diff, for example 'v3'
+        :type version_from: String
+        :param version_to: ending project version tag for getting diff
+        :type version_to: String
+        """
+        job = download_diffs_async(self, project_dir, file_path, version_from, version_to)
+        pull_project_wait(job)
+        download_diffs_finalize(job, output_diff)