Question

我有一个简单的Cells示例，我想与Devise和Rails集成。但是，所有示例和问题似乎都适用于单元格3.以下内容在我的应用程序中失败（添加了行号）。

line 1: class UserCell < Cell::ViewModel
line 2:   include Devise::Controllers::Helpers
line 3:
line 4:   def index
line 5:     render
line 6:   end
line 7: end

为第2行引发此错误。

undefined method `helper_method' for UserCell:Class

Answer 1

事实证明，默认情况下，Cell不再配置为与Rails一样工作（通过Cell :: Rails）。我不得不添加抽象控制器助手，但这让我自动在我的单元格中找到了所有设计助手。

class UserCell < Cell::ViewModel
   include AbstractController::Helpers
   include Devise::Controllers::Helpers

   def index
     render
   end
 end

Answer 2

另一种方法是

// circuit -- circuit simulator

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

// command parsing control
// NOTE: this can be build up if desired
struct cmd {
    const char *cmd_str;                    // command string
    const char *(*cmd_parse)(struct cmd *); // command parse function
};

// forward declarations
const char *parse_inputvar(struct cmd *cmd);
const char *parse_outputvar(struct cmd *cmd);
const char *parse_and(struct cmd *cmd);
const char *parse_or(struct cmd *cmd);

// list of supported commands
struct cmd cmdlist[] = {
    { .cmd_str = "INPUTVAR", .cmd_parse = parse_inputvar },
    { .cmd_str = "OUTPUTVAR", .cmd_parse = parse_outputvar },
    { .cmd_str = "AND", .cmd_parse = parse_and },
    { .cmd_str = "OR", .cmd_parse = parse_or },
    { .cmd_str = NULL }
};

int
main(int argc,char **argv)
{
    FILE *circuit;
    char line[5000];
    char *cp;
    struct cmd *cmd;
    const char *err;

    --argc;
    ++argv;

    circuit = fopen(*argv, "r");

    while (1) {
        cp = fgets(line, sizeof(line), circuit);
        if (cp == NULL)
            break;

        cp = strchr(line,'\n');
        if (cp != NULL)
            *cp = 0;

        cp = strtok(line," ");

        err = NULL;
        for (cmd = cmdlist;  cmd->cmd_str != NULL;  ++cmd) {
            if (strcmp(cp,cmd->cmd_str) == 0) {
                err = cmd->cmd_parse(cmd);
                break;
            }
        }

        if (cmd->cmd_str == NULL)
            printf("unknown command -- '%s'\n",cp);

        if (err != NULL)
            printf("error in %s command -- %s\n",cmd->cmd_str,err);
    }

    fclose(circuit);
}

const char *
parse_inputvar(struct cmd *cmd)
{
    char *cp;
    char *sym;
    int cnt;
    int idx;
    const char *err = NULL;

    do {
        // get the count string
        cp = strtok(NULL," ");
        if (cp == NULL) {
            err = "missing count";
            break;
        }

        // decode count string into number
        cnt = atoi(cp);
        if (cnt <= 0) {
            err = "bad count";
            break;
        }

        for (idx = 0;  idx < cnt;  ++idx) {
            sym = strtok(NULL," ");

            if (sym == NULL) {
                err = "missing symbol";
                break;
            }

            // NOTE: sym will be invalid after we return so we need to preserve
            // it now
            sym = strdup(sym);

            // do whatever ...
        }
    } while (0);

    return err;
}

const char *
parse_outputvar(struct cmd *cmd)
{
    const char *err = NULL;

    return err;
}

const char *
parse_and(struct cmd *cmd)
{
    const char *err = NULL;

    return err;
}

const char *
parse_or(struct cmd *cmd)
{
    const char *err = NULL;

    return err;
}

您可以将所有内容委托给控制器

还有一种方法，特别是如果你想让你的单元格和控制器彼此独立，你可以在options {} hash中将对象和属性传递给你的单元格。

Rails Cells 4：访问Devise助手

2 个答案: