我试图在Ruby on Rails中为多对多关系实现多选，但是我无法访问表示user_ids字段中所选用户ID的字符串数组。
点击更新后，以下是我的import os
import numpy as np
import pandas as pd
from matplotlib.mlab import griddata
from mpl_toolkits.basemap import Basemap
import matplotlib.pyplot as plt
from matplotlib.colors import Normalize
from shapely.geometry import mapping, Polygon, LineString,MultiLineString
import fiona
# set up plot
plt.clf()
fig = plt.figure(figsize=(10, 8))
ax = fig.add_subplot(111, axisbg='w', frame_on=False)
# grab data
data = pd.read_csv('Filename.csv', sep=',')
norm = Normalize()
# define map extent
lllon = -180
lllat = -90
urlon = 180
urlat = 90
# Set up Basemap instance
m = Basemap(#projection = 'merc',llcrnrlon = lllon, llcrnrlat = lllat, urcrnrlon = urlon, urcrnrlat = urlat,resolution='h', epsg=4326)
# transform lon / lat coordinates to map projection
data['projected_lon'], data['projected_lat'] = m(*(data.CLON.values, data.CLAT.values))
# grid data
numcols, numrows = 100, 100
xi = np.linspace(data['projected_lon'].min(), data['projected_lon'].max(), numcols)
yi = np.linspace(data['projected_lat'].min(), data['projected_lat'].max(), numrows)
xi, yi = np.meshgrid(xi, yi)
# interpolate
x, y, z = data['projected_lon'].values, data['projected_lat'].values, data.PRES.values
zi = griddata(x, y, z, xi, yi)
# contour plot
cs = plt.contour(xi, yi, zi,zorder=4)
plt.show()
lenvar = (len(cs.collections)) #number of contours
print(lenvar)
#print(cs.collections)
lines = [] # Empty list for contour sections
for i in range(lenvar):
n = i
p = cs.collections[i].get_paths()[0]
v = p.vertices # getting the individual verticies as a numpy.ndarray
x = v[:,0] #takes first column
y = v[:,1] #takes second column
line = LineString([(i[0], i[1]) for i in zip(x,y)]) #Defines Linestring
lines.append(line) #appends to list
schema = {'geometry': 'LineString','properties': {'id': 'int'}} # sets up parameter for shapefile
with fiona.open('ConShp.shp', 'w', 'ESRI Shapefile', schema) as c: # creates new file to be written to
for j in range(len(lines)):
l = (lines[j]) # creates variable
print(l)
print(type(l))
c.write({'geometry': mapping(l),'properties': {'id': j},})
project_params以下是我的"project"=>{"name"=>"Project Name",
"client"=>"Client X", "project_url"=>""},
"user_ids"=>["2", "3", "4", "5"], "commit"=>"Update Project", "id"=>"1"}
代码
ProjectsController第 def update
puts project_params[:user_ids=>[]]
respond_to do |format|
if @project.update(project_params)
format.html { redirect_to @project, notice: 'Project was successfully updated.' }
format.json { render :show, status: :ok, location: @project }
else
format.html { render :edit }
format.json { render json: @project.errors, status: :unprocessable_entity }
end
end
end
def project_params
params.require(:project).permit(:id, :name, :client, :project_url, :user_ids => [])
end
行打印一个空白行。我还尝试了puts project_params[:user_ids=>[]]和puts project_params[:user_ids] - 其中没有一项工作
以下是我的puts project_params[:user_ids[]]代码
_form.html.erb答案 0 :(得分：1)
select标签将使用第一个参数作为键。因此，值位于：
tableView.reloadSections(IndexSet(integer: indexPath.section),
with: UITableViewRowAnimation.fade)
或者如果您正在使用表单构建器
params[:user_ids]
然后它将在<%= form_for @project do |f| %>
<%= f.select :user_ids,
options_from_collection_for_select(User.all, "id", "name", @project.user),
{ :multiple => true, :size =>10}
%>
<% end %>