Source code for opc.rels

from .base import XmlTypeobjBase
from .parser import Parser




class Relationships(XmlTypeobjBase):
    """Class for object that represents the xml of |relspart| of the package.
    Inherits XmlTypeobjBase class. Xml of rels part is available as self.e
    """
    xmlns = "http://schemas.openxmlformats.org/package/2006/relationships"



    def get_target_rel_uri_str(self, rid):
        """Method to get the target value of a relation given by rid

        :param rid: relation id string value
        :returns: string value of relationship's target value in xml

        Example::

            presentation_relspart = presentation_part.get_rels_part()
            relationships = presentation_relspart.typeobj

            # say the relationship xml is as below
            # <Relationship Id="rId2" Target="slides/slide1.xml" Type="..." />

            print(relationships.get_target_rel_uri_str('rId2'))
            # slides/slide1.xml
        """
        for r in self.e:
            if r.get('Id') == rid:
                return r.get('Target')




    def get_lst_target_rel_uri_str(self, reltype):
        """Gets the list of relative uri of the target related by the given
        reltype

        :param reltype: str value
        :returns: list of Target attribute values of parts related by reltype
        """
        lst = []
        for r in self.e:
            if r.get('Type') == reltype:
                lst.append(r.get('Target'))
        return lst




    def init_e(self):
        """Add Relationships xml to the self.part object
        """
        parser = Parser()
        self.e = parser.makeelement('Relationships', nsmap={None: self.xmlns})




    def add_relation(self, type, target, target_mode=None):
        """Adds Relationships element to the xml. Assigns new Id and sets the
        Type, Target, TargetMode attributes to the element.

        :param type: str value of reltype
        :param target: relative uri str value of the part target wrt to part
            of this relspart object
        :param target_mode: optional param. Default value is None. No attribute
            TargetMode sets to the Relationships element if it is None. The
            value passed must be str type
        :returns: str value of the new id assigned to the element
        """

        parser = Parser()
        id = self.get_next_id()
        attrib = {'Id': id, 'Type': type, 'Target': target}
        if target_mode:
            attrib['TargetMode'] = target_mode
        rel = parser.makeelement(
            'Relationship', attrib=attrib, nsmap={None: self.xmlns})
        self.e.append(rel)
        return id




    def get_next_id(self):
        """Returns the new available id for the new relationship element
        :returns: str value of the new available id
        """
        used = 0
        for r in self.e:
            id = int(r.get('Id').replace('rId', ''))
            if id > used:
                used = id
        return 'rId'+str(used + 1)