Merge pull request #215 from snowman2/exceptions

add proj error message to exceptions

Author: snowman2

pyproj/_datadir.pxd

@@ -1,4 +1,3 @@
 include "proj.pxi"
 
-
 cdef PJ_CONTEXT* get_pyproj_context()

pyproj/_datadir.pyx

@@ -1,8 +1,16 @@
 
 from libc.stdlib cimport malloc, free
 
-from pyproj.compat import cstrencode
+from pyproj.compat import cstrencode, pystrdecode
 from pyproj.datadir import get_data_dir
+from pyproj.exceptions import ProjError
+
+cdef void pyproj_log_function(void *user_data, int level, const char *error_msg):
+    """
+    Log function for proj.4 errors with CRS class.
+    """
+    if level == PJ_LOG_ERROR:
+        ProjError.internal_proj_error = pystrdecode(error_msg)
 
 
 cdef PJ_CONTEXT* get_pyproj_context():
@@ -16,11 +24,13 @@ cdef PJ_CONTEXT* get_pyproj_context():
             b_data_dir = cstrencode(data_dir_list[iii])
             c_data_dir[iii] = b_data_dir
         proj_context_set_search_paths(pyproj_context, len(data_dir_list), c_data_dir)
-        proj_context_use_proj4_init_rules(pyproj_context, 1)
     except:
         if pyproj_context != NULL:
             proj_context_destroy(pyproj_context)
         raise
     finally:
         free(c_data_dir)
+    proj_context_use_proj4_init_rules(pyproj_context, 1)
+    proj_log_func(pyproj_context, NULL, pyproj_log_function)
+
     return pyproj_context

pyproj/exceptions.py

@@ -4,13 +4,26 @@
 """
 
 
-class CRSError(RuntimeError):
-    """Raised when a CRS error occurs."""
-
-
 class ProjError(RuntimeError):
     """Raised when a Proj error occurs."""
 
+    internal_proj_error = None
+
+    def __init__(self, error_message):
+        if self.internal_proj_error is not None:
+            error_message = (
+                "{error_message}: (Internal Proj Error: {internal_proj_error})"
+            ).format(
+                error_message=error_message,
+                internal_proj_error=self.internal_proj_error,
+            )
+            self.internal_proj_error = None
+        super(ProjError, self).__init__(error_message)
+
+
+class CRSError(ProjError):
+    """Raised when a CRS error occurs."""
+
 
 class GeodError(RuntimeError):
     """Raised when a Geod error occurs."""

pyproj/proj.pxi

@@ -24,6 +24,16 @@ cdef extern from "proj.h":
     ctypedef struct PJ_CONTEXT
     PJ_CONTEXT *proj_context_create ()
     PJ_CONTEXT *proj_context_destroy (PJ_CONTEXT *ctx)
+
+    ctypedef enum PJ_LOG_LEVEL:
+        PJ_LOG_NONE  = 0
+        PJ_LOG_ERROR = 1
+        PJ_LOG_DEBUG = 2
+        PJ_LOG_TRACE = 3
+        PJ_LOG_TELL  = 4
+    ctypedef void (*PJ_LOG_FUNCTION)(void *, int, const char *)
+    void proj_log_func (PJ_CONTEXT *ctx, void *app_data, PJ_LOG_FUNCTION logf)
+
     int  proj_errno (const PJ *P)
     int proj_context_errno (PJ_CONTEXT *ctx)
     const char * proj_errno_string (int err)

unittest/test_exception_logging.py

@@ -0,0 +1,14 @@
+import pytest
+
+from pyproj import CRS, Proj
+from pyproj.exceptions import CRSError, ProjError
+
+
+def test_proj_exception():
+    with pytest.raises(ProjError, match="Internal Proj Error"):
+        Proj("+proj=bobbyjoe")
+
+
+def test_crs_exception():
+    with pytest.raises(CRSError, match="Internal Proj Error"):
+        CRS("+proj=bobbyjoe")