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my-v0-server/app/actions/update.py
T

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5.4 KiB
Python

"""在大屏 JSON 副本上按路径更新组件属性,用于后端校验动作能否执行"""
from copy import deepcopy
from app.actions.base import BaseActionHandler
from app.schemas.actions import UpdateAction
from app.schemas.screen import Screen, ScreenNode
def fit_existing_path(node: ScreenNode, action: UpdateAction) -> UpdateAction:
"""字段定义允许的路径在组件中可能还没有中间对象(例如未开启过的数值标签)
前端只按已有路径赋值,这里把缺失的部分折叠进值里:改为更新最近的已有对象,
值为补齐的嵌套对象;缺失的若是数组元素则无法补齐,保持原样交给执行时报错
"""
if action.section == "name":
return action
current = getattr(node, action.section) or {}
for index, segment in enumerate(action.path[:-1]):
if isinstance(current, dict) and isinstance(segment, str) and segment not in current:
rest = action.path[index + 1 :]
if not all(isinstance(item, str) for item in rest):
return action
value = action.value
for item in reversed(rest):
value = {item: value}
return action.model_copy(
update={"path": action.path[: index + 1], "value": value}
)
if isinstance(current, dict) and isinstance(segment, str):
current = current[segment]
elif isinstance(current, list) and type(segment) is int and segment < len(current):
current = current[segment]
else:
return action
return action
class UpdateHandler(BaseActionHandler[UpdateAction]):
def apply(self, screen: Screen, action: UpdateAction) -> Screen:
# 确认目标存在,后续路径访问和赋值均在大屏副本中进行
result, target = self.copy_target(screen, action.target_id)
# 组件名称是节点顶层字段,没有后续路径
if action.section == "name":
target.name = action.value
return result
# 未设置的 style 视为空对象,只允许直接添加末级字段
if action.section == "style" and target.style is None:
target.style = {}
# 获取动作指定的属性区域,作为路径遍历的起点
current = getattr(target, action.section)
# 逐段访问路径,只有到达末级时才写入新值
for index, segment in enumerate(action.path):
# 标记当前是否为末级,用于区分继续访问和最终赋值
last = index == len(action.path) - 1
# 保存走到当前段的路径,异常时指出具体失败位置
location = f"{action.section} {action.path[: index + 1]!r}"
# 如果当前容器是字典,路径段必须是字符串键
if isinstance(current, dict):
if not isinstance(segment, str):
raise ValueError(f"对象路径必须使用字符串键: {location}")
# 中间层必须已存在,只允许在末级新增键,避免凭空构造嵌套结构
if not last and segment not in current:
raise ValueError(f"中间路径不存在: {location}")
elif isinstance(current, list):
# 数组只接受整数下标,使用精确类型判断排除 bool
if type(segment) is not int:
raise ValueError(f"数组路径必须使用整数下标: {location}")
# 只允许访问已有元素,不接受负下标,也不通过赋值扩展数组
if not 0 <= segment < len(current):
raise ValueError(f"数组下标越界: {location}")
else:
# 标量或 None 不能继续按路径访问,停止执行并返回明确错误
raise ValueError(f"路径无法继续访问,当前值不是对象或数组: {location}")
if last:
# 新值也复制,避免后续修改结果时影响 Action
current[segment] = deepcopy(action.value)
else:
# 尚未到达末级,进入已校验存在的下一层容器
current = current[segment]
# 返回属性更新后的大屏副本,原始大屏和动作值均未被修改
return result
if __name__ == "__main__":
screen = Screen.model_validate(
{
"canvas": {"width": 1920, "height": 1080},
"nodes": [
{
"id": "sales-chart",
"type": "chart",
"layout": {"x": 100, "y": 200, "width": 400, "height": 300},
"props": {"option": {"title": {"text": "销售额", "show": True}}},
}
],
}
)
action = UpdateAction(
target_id="sales-chart",
section="props",
path=["option", "title", "text"],
value="月度销售额",
)
handler = UpdateHandler()
final_screen = handler.apply(screen, action)
print(final_screen.model_dump_json(indent=2))
print("原始标题:", screen.nodes[0].props["option"]["title"]["text"])
try:
handler.apply(
screen,
UpdateAction(
target_id="sales-chart",
section="props",
path=["missing", "text"],
value="新标题",
),
)
except ValueError as error:
print("无效路径:", error)