#Summary

json-trim is a tool used to reduce unused JSON elements. It acts as a simple proxy server between the client and server allowing you to include or exclude attributes and nested objects via simple filter files.

#Usage

to start a local proxy server on port 8080 and a debug server on port 8081:

python server.py

note: you need to edit server.py to set the target server.

#Filtering

By default, all members of an object are filtered. json-trim's philosophy is to require explicit approval. Any values and nested objects which should be proxied are expressed in the JSON filter.

example:

{
 "attributes": ["keep_this_attribute", "and_this_one"],
 "childObject" : {
     "attributes": ["child_object_attribute_to_keep"]
 }
} 

In the example above, the attributes keep_this_attribute and and_this_one will be preserved. All nested objects will be removed except for the one named childObject. The attribute child_object_attribute_to_keep on childObject will also be preserved.

#Advanced Filtering

Child object filters can express required conditions for them to be used. This is done using the following key name:

child_attribute#parent_attribute#parent_attribute_required_value

example:

{
 "attributes": ["name", "ageClass"]
 "address#ageClass#adult": {
     "attributes": ["address", "city", "state"]
 }
 "address#ageClass#child": {
     "attributes": ["city", "state"]
 }
}

In the example above, the address object will preserve address, city, and state if the person has an ageClass of adult. If ageClass is child then only city and state are preserved. (Note: if ageClass is any other value, such as senior, it will be dropped.)

Although it is best to always explicitly include members of an object, it is possible to include all members and their children.

example:

{
 "!_include_all_children": true
}

#Debugging

Connecting to port 8081 returns the complete (unfiltered) JSON response. Keys which would be filtered will be left in lowercase while proxied keys will appear in UPPERCASE.

example:

{
 "droppedAttribute": "this key/value would not appear on port 8080.",
 "INCLUDEDATTRIBUTE": "this key/value would appear normally on port 8080."
}

#to do

1. basic code review (this is really rough at this point)
2. command line arguments
3. make sure POST is working