presta shop产品功能不会通过webservice添加

Question

我试图通过网络服务将产品添加到prestashop。能够添加所有内容但产品功能值未添加。功能标签在后端被选中但值为空。产品xml如下所示

<?xml version="1.0" encoding="UTF-8"?>
<prestashop xmlns:xlink="http://www.w3.org/1999/xlink">
<product>
    <id></id>
    <id_manufacturer>1</id_manufacturer>
    <id_supplier>1</id_supplier>
    <id_category_default>5</id_category_default>
    <new>1</new>
    <cache_default_attribute>1</cache_default_attribute>
    <id_default_image>1</id_default_image>
    <id_default_combination>1</id_default_combination>
    <id_tax_rules_group>1</id_tax_rules_group>
    <position_in_category>0</position_in_category>
    <type>simple</type>
    <id_shop_default>1</id_shop_default>
    <reference>demo_1</reference>
    <supplier_reference></supplier_reference>
    <location></location>
    <width>0.000000</width>
    <height>0.000000</height>
    <depth>0.000000</depth>
    <weight>0.000000</weight>
    <quantity_discount>0</quantity_discount>
    <ean13>0</ean13>
    <isbn></isbn>
    <upc></upc>
    <cache_is_pack>0</cache_is_pack>
    <cache_has_attachments>0</cache_has_attachments>
    <is_virtual>0</is_virtual>
    <state>1</state>
    <on_sale>0</on_sale>
    <online_only>0</online_only>
    <ecotax>0.000000</ecotax>
    <minimal_quantity>1</minimal_quantity>
    <price>12.00</price>
    <wholesale_price>10.00</wholesale_price>
    <unity></unity>
    <unit_price_ratio>0.000000</unit_price_ratio>
    <additional_shipping_cost>0</additional_shipping_cost>
    <customizable>0</customizable>
    <text_fields>0</text_fields>
    <uploadable_files>0</uploadable_files>
    <active>1</active>
    <redirect_type>404</redirect_type>
    <id_type_redirected>0</id_type_redirected>
    <available_for_order>1</available_for_order>
    <available_date>0000-00-00</available_date>
    <show_condition>0</show_condition>
    <condition>new</condition>
    <show_price>1</show_price>
    <indexed>1</indexed>
    <visibility>both</visibility>
    <advanced_stock_management>0</advanced_stock_management>
    <date_add></date_add>
    <date_upd></date_upd>
    <pack_stock_type>3</pack_stock_type>
    <meta_description><language id="1">dsgfdsgdf</language></meta_description>
    <meta_keywords><language id="1">fgdgdfgdf</language></meta_keywords>
    <meta_title><language id="1">dfgdfgdf</language></meta_title>
    <link_rewrite><language id="1"></language></link_rewrite>
    <name><language id="1">New Product</language></name>
    <description><language id="1">kk descritption</language></description>
    <description_short><language id="1">kk</language></description_short>
    <available_now><language id="1"></language></available_now>
    <available_later><language id="1"></language></available_later>
<associations>
<categories>
    <category>
    <id>2</id>
    </category>
</categories>
<images>
    <image>
    <id></id>
    </image>
</images>
<combinations>
    <combination>
    <id></id>
    </combination>
</combinations>
<product_option_values>
    <product_option_value>
    <id></id>
    </product_option_value>
</product_option_values>
<product_features>
    <product_feature>
        <id>8</id>
        <custom>1</custom>  
        <id_feature_value>222</id_feature_value>
    </product_feature>
</product_features>
<tags>
    <tag>
    <id></id>
    </tag>
</tags>
<stock_availables>
    <stock_available>
    <id>1</id>
    <id_product_attribute>0</id_product_attribute>
    </stock_available>
</stock_availables>
<accessories>
    <product>
    <id></id>
    </product>
</accessories>
<product_bundle>
    <product>
    <id></id>
    <quantity></quantity>
    </product>
</product_bundle>
</associations>
</product>
</prestashop>

下面给出了xml的特征部分

<product_features>
    <product_feature>
        <id>8</id>
        <custom>1</custom>  
        <id_feature_value>222</id_feature_value>
    </product_feature>
</product_features>

附上后端屏幕。