[Kimchi-devel] [PATCH 3/5] cdrom: Add convinient functions to deal with xml parse

[Aline Manera]

On 01/06/2014 07:32 AM, lvroyce at linux.vnet.ibm.com wrote:
> From: Royce Lv <lvroyce at linux.vnet.ibm.com>
>
> To format xml used to create cdrom, and to parse and filter cdrom
> query results, add three helper function to do this.
>
> Signed-off-by: Royce Lv <lvroyce at linux.vnet.ibm.com>
> ---
>   src/kimchi/model.py    | 42 ++++++++++++++++++++++++++++++++++++++++++
>   src/kimchi/xmlutils.py |  5 +++++
>   2 files changed, 47 insertions(+)
>
> diff --git a/src/kimchi/model.py b/src/kimchi/model.py
> index a21fcf7..c74c973 100644
> --- a/src/kimchi/model.py
> +++ b/src/kimchi/model.py
> @@ -1672,6 +1672,48 @@ def _get_volume_xml(**kwargs):
>       return xml
>
>
> +def _get_disk_xml(**kwargs):
> +    kwargs['readonly'] = "<readonly/>" \
> +                         if kwargs['target']['type'] == 'cdrom' else None

What about:

kargs['readonly'] = None
if kargs['target']['type'] == 'cdrom':
      kwargs['readonly'] = "<readonly/>"

that way we avoid breaking lines and make the code easier to read

> +    xml = """
> +    <disk type='{source[type]}' device='{target[type]}'>
> +        <source file='{source[path]}'/>
> +        <target dev='{target[name]}' bus='{target[bus]}'/>
> +        {readonly}
> +    </disk>
> +    """.format(**kwargs)
> +    return dict(xml=xml)
> +
> +
> +def _parse_vm_disks(xml_str, filter_path, filter_name, filter_val):
> +    # xml_str: xml_str of all disks
> +    # filter_path: xpath of the filter attribute,
> +    #              such as './disk' or './disk/target'
> +    # filter_name: relative path of filter attr of disks etree element
> +    #              such as: type, bus
> +    # filter_val: expected value of filter name
> +    root = ElementTree.fromstring(xml_str)
> +    ret = []
> +    xpath = "%s/[@%s='%s']" % (filter_path, filter_name, filter_val)
> +    for disk in root.findall(xpath):
> +        name = disk.find('./target').attrib['dev']
> +        ret.append(name)
> +
> +    return ret
> +
> +
> +def _parse_device(xml_str, dev_name):
> +    xpath = "./disk/target[@dev='%s']/.." % dev_name
> +    root = ElementTree.fromstring(xml_str)
> +    ret = []
> +    disk = root.find(xpath)
> +    if disk:
> +        path = disk.find('./source').attrib['file']
> +        return dict(name=dev_name, path=path)
> +    else:
> +        raise NotFoundError
> +
> +
>   class LibvirtConnection(object):
>       def __init__(self, uri):
>           self.uri = uri
> diff --git a/src/kimchi/xmlutils.py b/src/kimchi/xmlutils.py
> index 51ff0ec..176ceb1 100644
> --- a/src/kimchi/xmlutils.py
> +++ b/src/kimchi/xmlutils.py
> @@ -40,3 +40,8 @@ def xml_item_update(xml, xpath, value):
>       item = root.find(xpath)
>       item.text = value
>       return ElementTree.tostring(root, encoding="utf-8")
> +
> +def xml_get_child(xml, xpath):
> +    root = ElementTree.fromstring(xml)
> +    item = root.find(xpath)
> +    return ElementTree.tostring(item, encoding="utf-8")