XmlEngine.py

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import beatbox
import xml.etree.ElementTree as ET
import traceback

import json

__author__ = "Matias Medina"
__date__ = "$11/07/2016 04:02:59 PM$"

class XmlEngine:
    
    # Create a map of attachments by id
    def getMapAttachments(self, parentIds, service):
        
        # Query to Salesforce to get the attachments
        query_result = service.query("SELECT Id, ParentId, Body FROM Attachment WHERE ParentId IN (" + parentIds + ")")
        records = query_result['records']
        total_records = query_result['size']
        query_locator = query_result['queryLocator']
        
        # Map id to xml string
        mapParentIdToXml = {}

        # Loop through, pulling the next 500 and appending it to your records dict
        while query_result['done'] is False and len(records) < total_records:
            query_result = service.queryMore(query_locator)
            query_locator = query_result['queryLocator']
            records = records + query_result['records']
        
        # Build the map
        for att in records:
            if att.Body != None:
                mapParentIdToXml[att.ParentId] = att.Body.decode('base64')
                
        return mapParentIdToXml
    
    # Read the xml and get the data needed to update Salesforce records
    def getDemandSavings(self, xmlStr):
        result = ""
        node = ""
        try:
            # Get the root node
            root = ET.fromstring(xmlStr)
            # Go through the xml nodes to get needed node
            for child in root:
                if "Project" in child.tag:
                    for secondChild in child:
                        if "ProjectDetails" in secondChild.tag:
                            for thirdChild in secondChild:
                                if "EnergySavingsInfo" in thirdChild.tag:
                                    for fourthChild in thirdChild:
                                        if "DemandSavings" in fourthChild.tag:
                                            node = fourthChild.text
            if node != "":
                result = float(node)
        except:
            print "Malformed XML, missing or invalid DemandSavings"
        return result
    
    # Loop through a list of records and update them
    def updateObject(self, recordsToUpdate, fieldToUpdate, fieldValue, objectType, service):
        updateList = []
        for id in recordsToUpdate:
            objectUpdate = {"Id": id, fieldToUpdate: fieldValue, "type": objectType}
            updateList.append(objectUpdate)
        try:
            service.update(objectUpdate)
        except:
            print "failed"
            
    def runScript(self):
        # Initialize the beatbox api to talk to Salesforce
        service = beatbox.PythonClient()
        # Read credentials to log in Salesforce
        with open('settings.json') as data_file:    
            projectSettings = json.load(data_file)
        service.serverUrl = str(projectSettings["SF_SERVER_URL"])
        service.login(str(projectSettings["SF_ORG_USER"]), str(projectSettings["SF_ORG_PASSWORD"]))
        # The "parentId" needs to be replaced by the id of the record that have attached the xml file
        # you can pass a list of string if you want to work with more than one record
        xmlByIdMap = self.getMapAttachments("parentId", service);
        # Get the attachment stored at the map. Replace "appFileId" with the record id that contains the attachment
        # that you you want to parse
        xmlString = xmlByIdMap["appFileId"]
        # Get the value needed from xml file. This value will be used to update an especific record in Salesforce
        demandSavings = self.getDemandSavings(xmlString)
        # Replace recordsToUpdate by the list of records to update with the parsed value
        # Replace fieldToUpdate by the name of the field that you want to update. Eg: Demand_Savings__c
        # Replace objectType by the object that you want to update. Eg: MyCustomObject__c
        self.updateObject("recordsToUpdate", "fieldToUpdate", demandSavings, "objectType", service)